Keyword: astrophysics - astrophysics of galaxies
2023 (3)
iMaNGA: mock MaNGA galaxies based on IllustrisTNG and MaStar SSPs. – III. Stellar metallicity drivers in MaNGA and TNG50. Nanni, L., Neumann, J., Thomas, D., Maraston, C., Trayford, J., Lovell, C. C., Law, D. R., Yan, R., & Chen, Y. September, 2023. arXiv:2309.14257 null
![iMaNGA: mock MaNGA galaxies based on IllustrisTNG and MaStar SSPs. – III. Stellar metallicity drivers in MaNGA and TNG50 [link]](https://bibbase.org/img/filetypes/link.svg "link")
Paper doi abstract bibtex
Paper doi abstract bibtex The iMaNGA project uses a forward-modelling approach to compare the predictions of cosmological simulations with observations from SDSS-IV/MaNGA. We investigate the dependency of age and metallicity radial gradients on galaxy morphology, stellar mass, stellar surface mass density (${\}Sigma_*$), and environment. The key of our analysis is that observational biases affecting the interpretation of MaNGA data are emulated in the theoretical iMaNGA sample. The simulations reproduce the observed global stellar population scaling relations with positive correlations between galaxy mass and age/metallicity quite well and also produce younger stellar populations in late-type in agreement with observations. We do find interesting discrepancies, though, that can inform the physics and further development of the simulations. Ages of spiral galaxies and low-mass ellipticals are overestimated by about 2-4 Gyr. Radial metallicity gradients are steeper in iMaNGA than in MaNGA, a discrepancy most prominent in spiral and lenticular galaxies. Also, the observed steepening of metallicity gradients with increasing galaxy mass is not well matched by the simulations. We find that the theoretical radial profiles of surface mass density ${\}Sigma_*$ are steeper than in observations except for the most massive galaxies. In both MaNGA and iMaNGA [Z/H] correlates with ${\}Sigma_*$, however, the simulations systematically predict lower [Z/H] by almost a factor of 2 at any ${\}Sigma_*$. Most interestingly, for galaxies with stellar mass ${\}log M_*{\}leq 10.80 M_{\}odot$ the MaNGA data reveal a positive correlation between galaxy radius and [Z/H] at fixed ${\}Sigma_*$, which is not recovered in iMaNGA. Finally, the dependence on environmental density is negligible in both the theoretical iMaNGA and the observed MaNGA data.
@misc{nanni_imanga_2023,
title = {{iMaNGA}: mock {MaNGA} galaxies based on {IllustrisTNG} and {MaStar} {SSPs}. -- {III}. {Stellar} metallicity drivers in {MaNGA} and {TNG50}},
shorttitle = {{iMaNGA}},
url = {http://arxiv.org/abs/2309.14257},
doi = {10.48550/arXiv.2309.14257},
abstract = {The iMaNGA project uses a forward-modelling approach to compare the predictions of cosmological simulations with observations from SDSS-IV/MaNGA. We investigate the dependency of age and metallicity radial gradients on galaxy morphology, stellar mass, stellar surface mass density (\${\textbackslash}Sigma\_*\$), and environment. The key of our analysis is that observational biases affecting the interpretation of MaNGA data are emulated in the theoretical iMaNGA sample. The simulations reproduce the observed global stellar population scaling relations with positive correlations between galaxy mass and age/metallicity quite well and also produce younger stellar populations in late-type in agreement with observations. We do find interesting discrepancies, though, that can inform the physics and further development of the simulations. Ages of spiral galaxies and low-mass ellipticals are overestimated by about 2-4 Gyr. Radial metallicity gradients are steeper in iMaNGA than in MaNGA, a discrepancy most prominent in spiral and lenticular galaxies. Also, the observed steepening of metallicity gradients with increasing galaxy mass is not well matched by the simulations. We find that the theoretical radial profiles of surface mass density \${\textbackslash}Sigma\_*\$ are steeper than in observations except for the most massive galaxies. In both MaNGA and iMaNGA [Z/H] correlates with \${\textbackslash}Sigma\_*\$, however, the simulations systematically predict lower [Z/H] by almost a factor of 2 at any \${\textbackslash}Sigma\_*\$. Most interestingly, for galaxies with stellar mass \${\textbackslash}log M\_*{\textbackslash}leq 10.80 M\_{\textbackslash}odot\$ the MaNGA data reveal a positive correlation between galaxy radius and [Z/H] at fixed \${\textbackslash}Sigma\_*\$, which is not recovered in iMaNGA. Finally, the dependence on environmental density is negligible in both the theoretical iMaNGA and the observed MaNGA data.},
urldate = {2023-09-26},
publisher = {arXiv},
author = {Nanni, Lorenza and Neumann, Justus and Thomas, Daniel and Maraston, Claudia and Trayford, James and Lovell, Christopher C. and Law, David R. and Yan, Renbin and Chen, Yanping},
month = sep,
year = {2023},
note = {arXiv:2309.14257 null},
keywords = {Astrophysics - Astrophysics of Galaxies},
}Identifying the SN 2022acko progenitor with JWST. Van Dyk, S. D., Bostroem, K. A., Zheng, W., Brink, T. G., Fox, O. D., Andrews, J. E., Filippenko, A. V., Dong, Y., Hoang, E., Hosseinzadeh, G., Janzen, D., Jencson, J. E., Lundquist, M. J., Meza, N., Milisavljevic, D., Pearson, J., Sand, D. J., Shrestha, M., Valenti, S., & Howell, D. A. \mnras, 524(2):2186-2194, September, 2023.
doi bibtex
doi bibtex
@ARTICLE{2023MNRAS.524.2186V,
author = {{Van Dyk}, Schuyler D. and {Bostroem}, K. Azalee and {Zheng}, WeiKang and {Brink}, Thomas G. and {Fox}, Ori D. and {Andrews}, Jennifer E. and {Filippenko}, Alexei V. and {Dong}, Yize and {Hoang}, Emily and {Hosseinzadeh}, Griffin and {Janzen}, Daryl and {Jencson}, Jacob E. and {Lundquist}, Michael J. and {Meza}, Nicolas and {Milisavljevic}, Dan and {Pearson}, Jeniveve and {Sand}, David J. and {Shrestha}, Manisha and {Valenti}, Stefano and {Howell}, D. Andrew},
title = "{Identifying the SN 2022acko progenitor with JWST}",
journal = {\mnras},
keywords = {stars: evolution, stars: massive, supernovae: general, supernovae: individual: SN 2022acko, Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Astrophysics of Galaxies, Astrophysics - Solar and Stellar Astrophysics},
year = 2023,
month = sep,
volume = {524},
number = {2},
pages = {2186-2194},
doi = {10.1093/mnras/stad2001},
archivePrefix = {arXiv},
eprint = {2302.00274},
primaryClass = {astro-ph.HE},
adsurl = {https://ui.adsabs.harvard.edu/abs/2023MNRAS.524.2186V},
adsnote = {Provided by the SAO/NASA Astrophysics Data System}
}First light and reionization epoch simulations (FLARES) X: environmental galaxy bias and survey variance at high redshift. Thomas, P. A., Lovell, C. C., Maltz, M. G. A., Vijayan, A. P., Wilkins, S. M., Irodotou, D., Roper, W. J., & Seeyave, L. Monthly Notices of the Royal Astronomical Society, 524:43–59, September, 2023. ADS Bibcode: 2023MNRAS.524...43T
Paper doi abstract bibtex
Paper doi abstract bibtex Upcoming deep galaxy surveys with JWST will probe galaxy evolution during the epoch of reionization (EoR, 5 ≤ z ≤ 10) over relatively compact areas (e.g. ~300 arcmin2 for the JADES GTO survey). It is therefore imperative that we understand the degree of survey variance to evaluate how representative the galaxy populations in these studies will be. We use the First Light And Reionization Epoch Simulations (FLARES) to measure the galaxy bias of various tracers over an unprecedentedly large range in overdensity for a hydrodynamic simulation, and use these relations to assess the impact of bias and clustering on survey variance in the EoR. Star formation is highly biased relative to the underlying dark matter distribution, with the mean ratio of the stellar to dark matter density varying by a factor of 100 between regions of low and high matter overdensity (smoothed on a scale of 14 h-1 cMpc). This is reflected in the galaxy distribution - the most massive galaxies are found solely in regions of high overdensity. As a consequence of the above, galaxies in the EoR are highly clustered, which can lead to a large variance in survey number counts. For mean number counts N ≲ 100 (1000), in a unit redshift slice of angular area 300 arcmin2 (1.4 deg2), the 2σ range in N is roughly a factor of four (two). We present relations between the expected variance and survey area for different survey geometries; these relations will be of use to observers wishing to understand the impact of survey variance on their results.
@article{thomas_first_2023,
title = {First light and reionization epoch simulations ({FLARES}) {X}: environmental galaxy bias and survey variance at high redshift},
volume = {524},
issn = {0035-8711},
shorttitle = {First light and reionization epoch simulations ({FLARES}) {X}},
url = {https://ui.adsabs.harvard.edu/abs/2023MNRAS.524...43T},
doi = {10.1093/mnras/stad1819},
abstract = {Upcoming deep galaxy surveys with JWST will probe galaxy evolution during the epoch of reionization (EoR, 5 ≤ z ≤ 10) over relatively compact areas (e.g. {\textasciitilde}300 arcmin2 for the JADES GTO survey). It is therefore imperative that we understand the degree of survey variance to evaluate how representative the galaxy populations in these studies will be. We use the First Light And Reionization Epoch Simulations (FLARES) to measure the galaxy bias of various tracers over an unprecedentedly large range in overdensity for a hydrodynamic simulation, and use these relations to assess the impact of bias and clustering on survey variance in the EoR. Star formation is highly biased relative to the underlying dark matter distribution, with the mean ratio of the stellar to dark matter density varying by a factor of 100 between regions of low and high matter overdensity (smoothed on a scale of 14 h-1 cMpc). This is reflected in the galaxy distribution - the most massive galaxies are found solely in regions of high overdensity. As a consequence of the above, galaxies in the EoR are highly clustered, which can lead to a large variance in survey number counts. For mean number counts N ≲ 100 (1000), in a unit redshift slice of angular area 300 arcmin2 (1.4 deg2), the 2σ range in N is roughly a factor of four (two). We present relations between the expected variance and survey area for different survey geometries; these relations will be of use to observers wishing to understand the impact of survey variance on their results.},
urldate = {2024-01-13},
journal = {Monthly Notices of the Royal Astronomical Society},
author = {Thomas, Peter A. and Lovell, Christopher C. and Maltz, Maxwell G. A. and Vijayan, Aswin P. and Wilkins, Stephen M. and Irodotou, Dimitrios and Roper, William J. and Seeyave, Louise},
month = sep,
year = {2023},
note = {ADS Bibcode: 2023MNRAS.524...43T},
keywords = {Astrophysics - Astrophysics of Galaxies, galaxies: high-redshift, galaxies: luminosity function, mass function},
pages = {43--59},
}2022 (7)
A new emulated Monte Carlo radiative transfer disc-wind model: X-Ray Accretion Disc-wind Emulator - XRADE. Matzeu, G., Lieu, M., Costa, M., Reeves, J., Braito, V., Dadina, M., Nardini, E., Boorman, P., Parker, M., Sim, S., Barret, D., Kammoun, E., Middei, R., Giustini, M., Brusa, M., Cabrera, J. P., & Marchesi, S. \mnras, 515(4):6172-6190, October, 2022.
doi bibtex
doi bibtex
@ARTICLE{2022MNRAS.515.6172M,
author = {{Matzeu}, G.~A. and {Lieu}, M. and {Costa}, M.~T. and {Reeves}, J.~N. and {Braito}, V. and {Dadina}, M. and {Nardini}, E. and {Boorman}, P.~G. and {Parker}, M.~L. and {Sim}, S.~A. and {Barret}, D. and {Kammoun}, E. and {Middei}, R. and {Giustini}, M. and {Brusa}, M. and {Cabrera}, J. P{\'e}rez and {Marchesi}, S.},
title = "{A new emulated Monte Carlo radiative transfer disc-wind model: X-Ray Accretion Disc-wind Emulator - XRADE}",
journal = {\mnras},
keywords = {radiative transfer, methods: numerical, techniques: spectroscopic, galaxies: active, galaxies: individual: PDS 456, Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Astrophysics of Galaxies, Astrophysics - Instrumentation and Methods for Astrophysics},
year = 2022,
month = oct,
volume = {515},
number = {4},
pages = {6172-6190},
doi = {10.1093/mnras/stac2155},
archivePrefix = {arXiv},
eprint = {2207.13731},
primaryClass = {astro-ph.HE},
adsurl = {https://ui.adsabs.harvard.edu/abs/2022MNRAS.515.6172M},
adsnote = {Provided by the SAO/NASA Astrophysics Data System}
}Quantum fluctuations masquerade as halos: Bounds on ultra-light dark matter from quadruply-imaged quasars. Laroche, A., Gilman, D., Li, X., Bovy, J., & Du, X. Technical Report June, 2022. ADS Bibcode: 2022arXiv220611269L Type: article
Paper abstract bibtex
Paper abstract bibtex Ultra-light dark matter (ULDM) refers to a class of theories, including ultra-light axions, in which particles with mass $m_\{{\}psi\} {\textless} 10{\textasciicircum}\{-20\}{\}, {\}rm\{eV\}$ comprise a significant fraction of the dark matter. A galactic scale de Broglie wavelength distinguishes these theories from cold dark matter (CDM), suppressing the overall abundance of structure on sub-galactic scales, and producing wave-like interference phenomena in the density profiles of halos. With the aim of constraining the particle mass, we analyze the flux ratios in a sample of eleven quadruple-image strong gravitational lenses. We account for the suppression of the halo mass function and concentration-mass relation predicted by ULDM theories, and the wave-like fluctuations in the host halo density profile, calibrating the model for the wave interference against numerical simulations of galactic-scale halos. We show that the granular structure of halo density profiles, in particular, the amplitude of the fluctuations, significantly impacts image flux ratios, and therefore inferences on the particle mass derived from these data. We infer relative likelihoods of CDM to ULDM of 8:1, 7:1, 6:1, and 4:1 for particle masses ${\}log_\{10\}(m_{\}psi/{\}rm\{eV\}){\}in[-22.5,-22.25], [-22.25,-22.0],[-22.0,-21.75], [-21.75,-21.5]$, respectively. Repeating the analysis and omitting fluctuations associated with the wave interference effects, we obtain relative likelihoods of CDM to ULDM with a particle mass in the same ranges of 98:1, 48:1, 26:1 and 18:1, highlighting the significant perturbation to image flux ratios associated with the fluctuations. Nevertheless, our results disfavor the lightest particle masses with $m_\{{\}psi\} {\textless} 10{\textasciicircum}\{-21.5\}{\},{\}rm\{eV\}$, adding to mounting pressure on ultra-light axions as a viable dark matter candidate.
@techreport{laroche_quantum_2022,
title = {Quantum fluctuations masquerade as halos: {Bounds} on ultra-light dark matter from quadruply-imaged quasars},
shorttitle = {Quantum fluctuations masquerade as halos},
url = {https://ui.adsabs.harvard.edu/abs/2022arXiv220611269L},
abstract = {Ultra-light dark matter (ULDM) refers to a class of theories, including ultra-light axions, in which particles with mass \$m\_\{{\textbackslash}psi\} {\textless} 10{\textasciicircum}\{-20\}{\textbackslash}, {\textbackslash}rm\{eV\}\$ comprise a significant fraction of the dark matter. A galactic scale de Broglie wavelength distinguishes these theories from cold dark matter (CDM), suppressing the overall abundance of structure on sub-galactic scales, and producing wave-like interference phenomena in the density profiles of halos. With the aim of constraining the particle mass, we analyze the flux ratios in a sample of eleven quadruple-image strong gravitational lenses. We account for the suppression of the halo mass function and concentration-mass relation predicted by ULDM theories, and the wave-like fluctuations in the host halo density profile, calibrating the model for the wave interference against numerical simulations of galactic-scale halos. We show that the granular structure of halo density profiles, in particular, the amplitude of the fluctuations, significantly impacts image flux ratios, and therefore inferences on the particle mass derived from these data. We infer relative likelihoods of CDM to ULDM of 8:1, 7:1, 6:1, and 4:1 for particle masses \${\textbackslash}log\_\{10\}(m\_{\textbackslash}psi/{\textbackslash}rm\{eV\}){\textbackslash}in[-22.5,-22.25], [-22.25,-22.0],[-22.0,-21.75], [-21.75,-21.5]\$, respectively. Repeating the analysis and omitting fluctuations associated with the wave interference effects, we obtain relative likelihoods of CDM to ULDM with a particle mass in the same ranges of 98:1, 48:1, 26:1 and 18:1, highlighting the significant perturbation to image flux ratios associated with the fluctuations. Nevertheless, our results disfavor the lightest particle masses with \$m\_\{{\textbackslash}psi\} {\textless} 10{\textasciicircum}\{-21.5\}{\textbackslash},{\textbackslash}rm\{eV\}\$, adding to mounting pressure on ultra-light axions as a viable dark matter candidate.},
urldate = {2022-08-10},
author = {Laroche, Alexander and Gilman, Daniel and Li, Xinyu and Bovy, Jo and Du, Xiaolong},
month = jun,
year = {2022},
note = {ADS Bibcode: 2022arXiv220611269L
Type: article},
keywords = {Astrophysics - Astrophysics of Galaxies, Astrophysics - Cosmology and Nongalactic Astrophysics},
}The Galactic Dust-Up: Modeling Dust Evolution in FIRE. Choban, C. R., Keres, D., Hopkins, P. F., Sandstrom, K. M., Hayward, C. C., & Faucher-Giguere, C. Technical Report January, 2022. Publication Title: arXiv e-prints ADS Bibcode: 2022arXiv220112369C Type: article
Paper abstract bibtex
Paper abstract bibtex Recent strides have been made developing dust evolution models for galaxy formation simulations but these approaches vary in their assumptions and degree of complexity. Here we introduce and compare two separate dust evolution models (labelled 'Elemental' and 'Species'), based on recent approaches, incorporated into the GIZMO code and coupled with FIRE-2 stellar feedback and ISM physics. Both models account for turbulent dust diffusion, stellar production of dust, dust growth via gas-dust accretion, and dust destruction from time-resolved supernovae, thermal sputtering in hot gas, and astration. The "Elemental" model tracks the evolution of generalized dust species and utilizes a simple, 'tunable' dust growth routine, while the "Species" model tracks the evolution of specific dust species with set chemical compositions and incorporates a physically motivated, two-phase dust growth routine. We test and compare these models in an idealized Milky Way-mass galaxy and find that while both produce reasonable galaxy-integrated dust-to-metals (D/Z) ratios and predict gas-dust accretion as the main dust growth mechanism, a chemically motivated model is needed to reproduce the observed scaling relation between individual element depletions and D/Z with column density and local gas density. We also find the inclusion of theoretical metallic iron and O-bearing dust species are needed in the case of specific dust species in order to match observations of O and Fe depletions, and the integration of a sub-resolution dense molecular gas/CO scheme is needed to both match observed C depletions and ensure carbonaceous dust is not overproduced in dense environments.
@techreport{choban_galactic_2022,
title = {The {Galactic} {Dust}-{Up}: {Modeling} {Dust} {Evolution} in {FIRE}},
shorttitle = {The {Galactic} {Dust}-{Up}},
url = {https://ui.adsabs.harvard.edu/abs/2022arXiv220112369C},
abstract = {Recent strides have been made developing dust evolution models for galaxy formation simulations but these approaches vary in their assumptions and degree of complexity. Here we introduce and compare two separate dust evolution models (labelled 'Elemental' and 'Species'), based on recent approaches, incorporated into the GIZMO code and coupled with FIRE-2 stellar feedback and ISM physics. Both models account for turbulent dust diffusion, stellar production of dust, dust growth via gas-dust accretion, and dust destruction from time-resolved supernovae, thermal sputtering in hot gas, and astration. The "Elemental" model tracks the evolution of generalized dust species and utilizes a simple, 'tunable' dust growth routine, while the "Species" model tracks the evolution of specific dust species with set chemical compositions and incorporates a physically motivated, two-phase dust growth routine. We test and compare these models in an idealized Milky Way-mass galaxy and find that while both produce reasonable galaxy-integrated dust-to-metals (D/Z) ratios and predict gas-dust accretion as the main dust growth mechanism, a chemically motivated model is needed to reproduce the observed scaling relation between individual element depletions and D/Z with column density and local gas density. We also find the inclusion of theoretical metallic iron and O-bearing dust species are needed in the case of specific dust species in order to match observations of O and Fe depletions, and the integration of a sub-resolution dense molecular gas/CO scheme is needed to both match observed C depletions and ensure carbonaceous dust is not overproduced in dense environments.},
urldate = {2022-02-22},
author = {Choban, Caleb R. and Keres, Dusan and Hopkins, Philip F. and Sandstrom, Karin M. and Hayward, Christopher C. and Faucher-Giguere, Claude-Andre},
month = jan,
year = {2022},
note = {Publication Title: arXiv e-prints
ADS Bibcode: 2022arXiv220112369C
Type: article},
keywords = {Astrophysics - Astrophysics of Galaxies},
}Massive Black Hole Binaries from the TNG50 Simulation: I. Coalescence and \textbackslashtextit\LISA\ Detection Rates. Kunyang, Li, Bogdanović, T., Ballantyne, D. R., & Bonetti, M. arXiv:2201.11088 [astro-ph], January, 2022. arXiv: 2201.11088
Paper abstract bibtex
Paper abstract bibtex We evaluate the cosmological coalescence and detection rates for massive black hole (MBH) binaries targeted by the gravitational wave observatory Laser Interferometer Space Antenna (\\textbackslashit LISA\). Our calculation starts with a population of gravitationally unbound MBH pairs, drawn from the TNG50-3 cosmological simulation, and follows their orbital evolution from kpc scales all the way to coalescence using a semi-analytic model developed in our previous work. We find that for a majority of MBH pairs that coalesce within a Hubble time dynamical friction is the most important mechanism that determines their coalescence rate. Our model predicts a MBH coalescence rate \${\textbackslash}lesssim 0.45\$\textasciitildeyr\${\textasciicircum}\{-1\}\$ and a \\textbackslashit LISA\ detection rate \${\textbackslash}lesssim 0.34\$\textasciitildeyr\${\textasciicircum}\{-1\}\$. Most \\textbackslashit LISA\ detections should originate from \$10{\textasciicircum}\{{\textbackslash}rm 6\} - 10{\textasciicircum}\{{\textbackslash}rm 6.8\}{\textbackslash},M_\{{\textbackslash}rm {\textbackslash}odot\}\$ MBHs in gas-rich galaxies at redshifts \$1.6 {\textbackslash}leq z {\textbackslash}leq 2.4\$, and have a characteristic signal to noise ratio SNR \${\textbackslash}sim 100\$. We however find a dramatic reduction in the coalescence and detection rates, as well as the average SNR, if the effects of radiative feedback from accreting MBHs are taken into account. In this case, the MBH coalescence rate is reduced by \$78{\textbackslash}%\$ (to \${\textbackslash}lesssim 0.1\$\textasciitildeyr\${\textasciicircum}\{-1\}\$), and the \textbackslashtextit\LISA\ detection rate is reduced by \$94{\textbackslash}%\$ (to \$0.02\$\textasciitildeyr\${\textasciicircum}\{-1\}\$), whereas the average SNR is \${\textbackslash}sim 10\$. We emphasize that our model provides a lower limit on the \textbackslashtextit\LISA\ detection rate, consistent with other works in the literature that draw their MBH pairs from cosmological simulations.
@article{kunyang_massive_2022,
title = {Massive {Black} {Hole} {Binaries} from the {TNG50} {Simulation}: {I}. {Coalescence} and {\textbackslash}textit\{{LISA}\} {Detection} {Rates}},
shorttitle = {Massive {Black} {Hole} {Binaries} from the {TNG50} {Simulation}},
url = {http://arxiv.org/abs/2201.11088},
abstract = {We evaluate the cosmological coalescence and detection rates for massive black hole (MBH) binaries targeted by the gravitational wave observatory Laser Interferometer Space Antenna (\{{\textbackslash}it LISA\}). Our calculation starts with a population of gravitationally unbound MBH pairs, drawn from the TNG50-3 cosmological simulation, and follows their orbital evolution from kpc scales all the way to coalescence using a semi-analytic model developed in our previous work. We find that for a majority of MBH pairs that coalesce within a Hubble time dynamical friction is the most important mechanism that determines their coalescence rate. Our model predicts a MBH coalescence rate \${\textbackslash}lesssim 0.45\${\textasciitilde}yr\${\textasciicircum}\{-1\}\$ and a \{{\textbackslash}it LISA\} detection rate \${\textbackslash}lesssim 0.34\${\textasciitilde}yr\${\textasciicircum}\{-1\}\$. Most \{{\textbackslash}it LISA\} detections should originate from \$10{\textasciicircum}\{{\textbackslash}rm 6\} - 10{\textasciicircum}\{{\textbackslash}rm 6.8\}{\textbackslash},M\_\{{\textbackslash}rm {\textbackslash}odot\}\$ MBHs in gas-rich galaxies at redshifts \$1.6 {\textbackslash}leq z {\textbackslash}leq 2.4\$, and have a characteristic signal to noise ratio SNR \${\textbackslash}sim 100\$. We however find a dramatic reduction in the coalescence and detection rates, as well as the average SNR, if the effects of radiative feedback from accreting MBHs are taken into account. In this case, the MBH coalescence rate is reduced by \$78{\textbackslash}\%\$ (to \${\textbackslash}lesssim 0.1\${\textasciitilde}yr\${\textasciicircum}\{-1\}\$), and the {\textbackslash}textit\{LISA\} detection rate is reduced by \$94{\textbackslash}\%\$ (to \$0.02\${\textasciitilde}yr\${\textasciicircum}\{-1\}\$), whereas the average SNR is \${\textbackslash}sim 10\$. We emphasize that our model provides a lower limit on the {\textbackslash}textit\{LISA\} detection rate, consistent with other works in the literature that draw their MBH pairs from cosmological simulations.},
urldate = {2022-01-27},
journal = {arXiv:2201.11088 [astro-ph]},
author = {Kunyang and Li and Bogdanović, Tamara and Ballantyne, David R. and Bonetti, Matteo},
month = jan,
year = {2022},
note = {arXiv: 2201.11088},
keywords = {Astrophysics - Astrophysics of Galaxies},
}The MUSE eXtremely Deep Field: Individual detections of Ly\\textbackslashalpha\ haloes around rest-frame UV-selected galaxies at z\textasciitilde2.9-4.4. Kusakabe, H., Verhamme, A., Blaizot, J., Garel, T., Wisotzki, L., Leclercq, F., Bacon, R., Schaye, J., Gallego, S. G., Kerutt, J., Matthee, J., Maseda, M., Nanayakkara, T., Pello, R., Richard, J., Tresse, L., Urrutia, T., & Vitte, E. arXiv:2201.07257 [astro-ph], January, 2022. arXiv: 2201.07257
Paper abstract bibtex
Paper abstract bibtex Hydrogen Ly\$\{{\textbackslash}alpha\}\$ haloes (LAHs) are commonly used as a tracer of the circumgalactic medium (CGM) at high redshifts. In this work, we aim to explore the existence of Ly\$\{{\textbackslash}alpha\}\$ haloes around individual UV-selected galaxies, rather than around Ly\$\{{\textbackslash}alpha\}\$ emitters (LAEs), at high redshifts. Our sample was continuum-selected with F775W\textless=27.5, and spectroscopic redshifts were assigned or constrained for all the sources thanks to the deepest (100- to 140-hour) existing Very Large Telescope (VLT)/Multi-Unit Spectroscopic Explorer (MUSE) data with adaptive optics. The final sample includes 21 galaxies that are purely F775W-magnitude selected within the redshift range z=2.9-4.4 and within a UV magnitude range -20\textless=M1500\textless= -18, thus avoiding any bias toward LAEs. We tested whether galaxy's Ly\$\{{\textbackslash}alpha\}\$ emission is significantly more extended than the MUSE PSF-convolved continuum component. We find 17 LAHs and four non-LAHs. We report the first individual detections of extended Ly\$\{{\textbackslash}alpha\}\$ emission around non-LAEs. The Ly\$\{{\textbackslash}alpha\}\$ halo fraction is thus as high as \$81.0{\textasciicircum}\{+10.3\}_\{-11.2\}\$%, which is close to that for LAEs at z=3-6 in the literature. This implies that UV-selected galaxies generally have a large amount of hydrogen in their CGM. We derived the mean surface brightness (SB) profile for our LAHs with cosmic dimming corrections and find that Ly\$\{{\textbackslash}alpha\}\$ emission extends to 5.4 arcsec (\textasciitilde40 physical kpc at the midpoint redshift z=3.6) above the typical 1\$\{{\textbackslash}sigma\}\$ SB limit. The incidence rate of surrounding gas detected in Ly\$\{{\textbackslash}alpha\}\$ per one-dimensional line of sight per unit redshift, dn/dz, is estimated to be \$0.76{\textasciicircum}\{+0.09\}_\{-0.09\}\$ for galaxies with M1500\textless= -18 mag at z\textasciitilde3.7. Assuming that Ly\$\{{\textbackslash}alpha\}\$ emission and absorption arise in the same gas, this suggests, based on abundance matching, that LAHs trace the same gas as damped Ly\$\{{\textbackslash}alpha\}\$ systems (DLAs) and sub-DLAs.
@article{kusakabe_muse_2022,
title = {The {MUSE} {eXtremely} {Deep} {Field}: {Individual} detections of {Ly}\{{\textbackslash}alpha\} haloes around rest-frame {UV}-selected galaxies at z{\textasciitilde}2.9-4.4},
shorttitle = {The {MUSE} {eXtremely} {Deep} {Field}},
url = {http://arxiv.org/abs/2201.07257},
abstract = {Hydrogen Ly\$\{{\textbackslash}alpha\}\$ haloes (LAHs) are commonly used as a tracer of the circumgalactic medium (CGM) at high redshifts. In this work, we aim to explore the existence of Ly\$\{{\textbackslash}alpha\}\$ haloes around individual UV-selected galaxies, rather than around Ly\$\{{\textbackslash}alpha\}\$ emitters (LAEs), at high redshifts. Our sample was continuum-selected with F775W{\textless}=27.5, and spectroscopic redshifts were assigned or constrained for all the sources thanks to the deepest (100- to 140-hour) existing Very Large Telescope (VLT)/Multi-Unit Spectroscopic Explorer (MUSE) data with adaptive optics. The final sample includes 21 galaxies that are purely F775W-magnitude selected within the redshift range z=2.9-4.4 and within a UV magnitude range -20{\textless}=M1500{\textless}= -18, thus avoiding any bias toward LAEs. We tested whether galaxy's Ly\$\{{\textbackslash}alpha\}\$ emission is significantly more extended than the MUSE PSF-convolved continuum component. We find 17 LAHs and four non-LAHs. We report the first individual detections of extended Ly\$\{{\textbackslash}alpha\}\$ emission around non-LAEs. The Ly\$\{{\textbackslash}alpha\}\$ halo fraction is thus as high as \$81.0{\textasciicircum}\{+10.3\}\_\{-11.2\}\$\%, which is close to that for LAEs at z=3-6 in the literature. This implies that UV-selected galaxies generally have a large amount of hydrogen in their CGM. We derived the mean surface brightness (SB) profile for our LAHs with cosmic dimming corrections and find that Ly\$\{{\textbackslash}alpha\}\$ emission extends to 5.4 arcsec ({\textasciitilde}40 physical kpc at the midpoint redshift z=3.6) above the typical 1\$\{{\textbackslash}sigma\}\$ SB limit. The incidence rate of surrounding gas detected in Ly\$\{{\textbackslash}alpha\}\$ per one-dimensional line of sight per unit redshift, dn/dz, is estimated to be \$0.76{\textasciicircum}\{+0.09\}\_\{-0.09\}\$ for galaxies with M1500{\textless}= -18 mag at z{\textasciitilde}3.7. Assuming that Ly\$\{{\textbackslash}alpha\}\$ emission and absorption arise in the same gas, this suggests, based on abundance matching, that LAHs trace the same gas as damped Ly\$\{{\textbackslash}alpha\}\$ systems (DLAs) and sub-DLAs.},
urldate = {2022-01-21},
journal = {arXiv:2201.07257 [astro-ph]},
author = {Kusakabe, Haruka and Verhamme, Anne and Blaizot, Jeremy and Garel, Thibault and Wisotzki, Lutz and Leclercq, Floriane and Bacon, Roland and Schaye, Joop and Gallego, Sofia G. and Kerutt, Josephine and Matthee, Jorryt and Maseda, Michael and Nanayakkara, Themiya and Pello, Roser and Richard, Johan and Tresse, Laurence and Urrutia, Tanya and Vitte, Eloise},
month = jan,
year = {2022},
note = {arXiv: 2201.07257},
keywords = {Astrophysics - Astrophysics of Galaxies, Astrophysics - Cosmology and Nongalactic Astrophysics},
}Mechanical feedback from stellar winds with an application to galaxy formation at high redshift. Fichtner, Y. A., Grassitelli, L., Romano-Diaz, E., & Porciani, C. arXiv:2201.07244 [astro-ph], January, 2022. arXiv: 2201.07244
Paper abstract bibtex
Paper abstract bibtex We compute different sets of stellar evolutionary tracks in order to quantify the energy, mass, and metals yielded by massive main-sequence and post-main-sequence winds. Our aim is to investigate the impact of binary systems and of a metallicity-dependent distribution of initial rotational velocities on the feedback by stellar winds. We find significant changes compared to the commonly used non-rotating, single-star scenario. The largest differences are noticeable at low metallicity, where the mechanical-energy budget is substantially increased. So as to establish the maximal (i.e. obtained by neglecting dissipation in the near circumstellar environment) influence of winds on the early stages of galaxy formation, we use our new feedback estimates to simulate the formation and evolution of a sub-\$L_*\$ galaxy at redshift 3 (hosted by a dark-matter halo with a mass of \$1.8{\textbackslash}times 10{\textasciicircum}\{11\}\$ M\$_{\textbackslash}odot\$) and compare the outcome with simulations in which only supernova feedback is considered. Accounting for the continuous energy injection by winds reduces the total stellar mass, the metal content, and the burstiness of the star-formation rate as well as of the outflowing gas mass. However, our numerical experiment suggests that the enhanced mechanical feedback from the winds of rotating and binary stars has a limited impact on the most relevant galactic properties compared to the non-rotating single-star scenario. Eventually, we look at the relative abundance between the metals entrained in winds and those ejected by supernovae and find that it stays nearly constant within the simulated galaxy and its surrounding halo.
@article{fichtner_mechanical_2022,
title = {Mechanical feedback from stellar winds with an application to galaxy formation at high redshift},
url = {http://arxiv.org/abs/2201.07244},
abstract = {We compute different sets of stellar evolutionary tracks in order to quantify the energy, mass, and metals yielded by massive main-sequence and post-main-sequence winds. Our aim is to investigate the impact of binary systems and of a metallicity-dependent distribution of initial rotational velocities on the feedback by stellar winds. We find significant changes compared to the commonly used non-rotating, single-star scenario. The largest differences are noticeable at low metallicity, where the mechanical-energy budget is substantially increased. So as to establish the maximal (i.e. obtained by neglecting dissipation in the near circumstellar environment) influence of winds on the early stages of galaxy formation, we use our new feedback estimates to simulate the formation and evolution of a sub-\$L\_*\$ galaxy at redshift 3 (hosted by a dark-matter halo with a mass of \$1.8{\textbackslash}times 10{\textasciicircum}\{11\}\$ M\$\_{\textbackslash}odot\$) and compare the outcome with simulations in which only supernova feedback is considered. Accounting for the continuous energy injection by winds reduces the total stellar mass, the metal content, and the burstiness of the star-formation rate as well as of the outflowing gas mass. However, our numerical experiment suggests that the enhanced mechanical feedback from the winds of rotating and binary stars has a limited impact on the most relevant galactic properties compared to the non-rotating single-star scenario. Eventually, we look at the relative abundance between the metals entrained in winds and those ejected by supernovae and find that it stays nearly constant within the simulated galaxy and its surrounding halo.},
urldate = {2022-02-04},
journal = {arXiv:2201.07244 [astro-ph]},
author = {Fichtner, Yvonne A. and Grassitelli, Luca and Romano-Diaz, Emilio and Porciani, Cristiano},
month = jan,
year = {2022},
note = {arXiv: 2201.07244},
keywords = {Astrophysics - Astrophysics of Galaxies, Astrophysics - Solar and Stellar Astrophysics},
}Deep Learning of DESI Mock Spectra to Find Damped Ly\\textbackslashalpha\ Systems. Wang, B., Zou, J., Cai, Z., Prochaska, J. X., Sun, Z., Ding, J., Font-Ribera, A., Gonzalez, A., Herrera-Alcantar, H. K., Irsic, V., Lin, X., Brooks, D., Chabanier, S., de Belsunce, R., Palanque-Delabrouille, N., Tarle, G., & Zhou, Z. arXiv:2201.00827 [astro-ph], January, 2022. arXiv: 2201.00827
Paper abstract bibtex
Paper abstract bibtex We have updated and applied a convolutional neural network (CNN) machine learning model to discover and characterize damped Ly\${\textbackslash}alpha\$ systems (DLAs) based on Dark Energy Spectroscopic Instrument (DESI) mock spectra. We have optimized the training process and constructed a CNN model that yields a DLA classification accuracy above 99\${\textbackslash}%\$ for spectra which have signal-to-noise (S/N) above 5 per pixel. Classification accuracy is the rate of correct classifications. This accuracy remains above 97\${\textbackslash}%\$ for lower signal-to-noise (S/N) \${\textbackslash}approx1\$ spectra. This CNN model provides estimations for redshift and HI column density with standard deviations of 0.002 and 0.17 dex for spectra with S/N above 3 per pixel. Also, this DLA finder is able to identify overlapping DLAs and sub-DLAs. Further, the impact of different DLA catalogs on the measurement of Baryon Acoustic Oscillation (BAO) is investigated. The cosmological fitting parameter result for BAO has less than \$0.61{\textbackslash}%\$ difference compared to analysis of the mock results with perfect knowledge of DLAs. This difference is lower than the statistical error for the first year estimated from the mock spectra: above \$1.7{\textbackslash}%\$. We also compared the performance of CNN and Gaussian Process (GP) model. Our improved CNN model has moderately 14\${\textbackslash}%\$ higher purity and 7\${\textbackslash}%\$ higher completeness than an older version of GP code, for S/N \${\textgreater}\$ 3. Both codes provide good DLA redshift estimates, but the GP produces a better column density estimate by \$24{\textbackslash}%\$ less standard deviation. A credible DLA catalog for DESI main survey can be provided by combining these two algorithms.
@article{wang_deep_2022,
title = {Deep {Learning} of {DESI} {Mock} {Spectra} to {Find} {Damped} {Ly}\{{\textbackslash}alpha\} {Systems}},
url = {http://arxiv.org/abs/2201.00827},
abstract = {We have updated and applied a convolutional neural network (CNN) machine learning model to discover and characterize damped Ly\${\textbackslash}alpha\$ systems (DLAs) based on Dark Energy Spectroscopic Instrument (DESI) mock spectra. We have optimized the training process and constructed a CNN model that yields a DLA classification accuracy above 99\${\textbackslash}\%\$ for spectra which have signal-to-noise (S/N) above 5 per pixel. Classification accuracy is the rate of correct classifications. This accuracy remains above 97\${\textbackslash}\%\$ for lower signal-to-noise (S/N) \${\textbackslash}approx1\$ spectra. This CNN model provides estimations for redshift and HI column density with standard deviations of 0.002 and 0.17 dex for spectra with S/N above 3 per pixel. Also, this DLA finder is able to identify overlapping DLAs and sub-DLAs. Further, the impact of different DLA catalogs on the measurement of Baryon Acoustic Oscillation (BAO) is investigated. The cosmological fitting parameter result for BAO has less than \$0.61{\textbackslash}\%\$ difference compared to analysis of the mock results with perfect knowledge of DLAs. This difference is lower than the statistical error for the first year estimated from the mock spectra: above \$1.7{\textbackslash}\%\$. We also compared the performance of CNN and Gaussian Process (GP) model. Our improved CNN model has moderately 14\${\textbackslash}\%\$ higher purity and 7\${\textbackslash}\%\$ higher completeness than an older version of GP code, for S/N \${\textgreater}\$ 3. Both codes provide good DLA redshift estimates, but the GP produces a better column density estimate by \$24{\textbackslash}\%\$ less standard deviation. A credible DLA catalog for DESI main survey can be provided by combining these two algorithms.},
urldate = {2022-01-05},
journal = {arXiv:2201.00827 [astro-ph]},
author = {Wang, Ben and Zou, Jiaqi and Cai, Zheng and Prochaska, J. Xavier and Sun, Zechang and Ding, Jiani and Font-Ribera, Andreu and Gonzalez, Alma and Herrera-Alcantar, Hiram K. and Irsic, Vid and Lin, Xiaojing and Brooks, David and Chabanier, Solène and de Belsunce, Roger and Palanque-Delabrouille, Nathalie and Tarle, Gregory and Zhou, Zhimin},
month = jan,
year = {2022},
note = {arXiv: 2201.00827},
keywords = {Astrophysics - Astrophysics of Galaxies, Astrophysics - Cosmology and Nongalactic Astrophysics},
}2021 (21)
Accelerated galaxy growth and environmental quenching in a protocluster at z=3.24. Shi, K., Toshikawa, J., Lee, K., Wang, T., Cai, Z., & Fang, T. arXiv e-prints, 2102:arXiv:2102.06499, February, 2021.
Paper abstract bibtex
Paper abstract bibtex We present a multiwavelength study of galaxies around D4UD01, a spectroscopically confirmed protocluster at z = 3.24 to investigate environmental trends. 450 galaxies are selected based on Ks band detection with photometric redshifts (photo-z) at 3.0 \textless z \textless 3.4, among which \textasciitilde 12% are classified as quiescent galaxies. The quiescent galaxies are among the most massive and reddest ones in the entire sample. We identify a large photo-z galaxy overdensity in the field, which lies close to the previously spectroscopically confirmed sources of the protocluster. We find that the quiescent galaxies are largely concentrated in the overdense protocluster region with a higher quiescent fraction, showing a sign of environmental quenching. Galaxies in the protocluster are forming faster than the field counterparts as seen in the stellar mass function, suggesting early and accelerated mass assembly in the overdense regions. Although weak evidence of suppressed star-formation is found in the protocluster, the statistics are not significant enough to draw a definite conclusion. Our work shed light on how the formation of massive galaxies is affected in the dense region of a protocluster when the Universe was only 2 Gyr old.
@article{shi_accelerated_2021,
title = {Accelerated galaxy growth and environmental quenching in a protocluster at z=3.24},
volume = {2102},
url = {http://adsabs.harvard.edu/abs/2021arXiv210206499S},
abstract = {We present a multiwavelength study of galaxies around D4UD01, a
spectroscopically confirmed protocluster at z = 3.24 to investigate
environmental trends. 450 galaxies are selected based on Ks band
detection with photometric redshifts (photo-z) at 3.0 {\textless} z {\textless} 3.4,
among which {\textasciitilde} 12\% are classified as quiescent galaxies. The quiescent
galaxies are among the most massive and reddest ones in the entire
sample. We identify a large photo-z galaxy overdensity in the field,
which lies close to the previously spectroscopically confirmed sources
of the protocluster. We find that the quiescent galaxies are largely
concentrated in the overdense protocluster region with a higher
quiescent fraction, showing a sign of environmental quenching. Galaxies
in the protocluster are forming faster than the field counterparts as
seen in the stellar mass function, suggesting early and accelerated mass
assembly in the overdense regions. Although weak evidence of suppressed
star-formation is found in the protocluster, the statistics are not
significant enough to draw a definite conclusion. Our work shed light on
how the formation of massive galaxies is affected in the dense region of
a protocluster when the Universe was only 2 Gyr old.},
urldate = {2021-02-15},
journal = {arXiv e-prints},
author = {Shi, Ke and Toshikawa, Jun and Lee, Kyoung-Soo and Wang, Tao and Cai, Zheng and Fang, Taotao},
month = feb,
year = {2021},
keywords = {Astrophysics - Astrophysics of Galaxies, Astrophysics - Cosmology and Nongalactic Astrophysics},
pages = {arXiv:2102.06499},
}Galactic Traversability: A New Concept for Extragalactic SETI. Lacki, B. C. arXiv e-prints, June, 2021.
Paper abstract bibtex
Paper abstract bibtex Interstellar travel in the Milky Way is commonly thought to be a long and dangerous enterprise, but are all galaxies so hazardous? I introduce the concept of galactic traversability to address this question. Stellar populations are one factor in traversability, with higher stellar densities and velocity dispersions aiding rapid spread across a galaxy. The interstellar medium (ISM) is another factor, as gas, dust grains, and cosmic rays (CRs) all pose hazards to starfarers. I review the current understanding of these components in different types of galaxies, and conclude that red quiescent galaxies without star formation have favorable traversability. Compact elliptical galaxies and globular clusters could be "super-traversable", because stars are packed tightly together and there are minimal ISM hazards. Overall, if the ISM is the major hindrance to interstellar travel, galactic traversability increases with cosmic time as gas fractions and star formation decline. Traversability is a consideration in extragalactic surveys for the search for extraterrestrial intelligence (SETI).
@article{lacki_galactic_2021,
title = {Galactic {Traversability}: {A} {New} {Concept} for {Extragalactic} {SETI}},
shorttitle = {Galactic {Traversability}},
url = {https://ui.adsabs.harvard.edu/abs/2021arXiv210607739L},
abstract = {Interstellar travel in the Milky Way is commonly thought to be a long and dangerous enterprise, but are all galaxies so hazardous? I introduce the concept of galactic traversability to address this question. Stellar populations are one factor in traversability, with higher stellar densities and velocity dispersions aiding rapid spread across a galaxy. The interstellar medium (ISM) is another factor, as gas, dust grains, and cosmic rays (CRs) all pose hazards to starfarers. I review the current understanding of these components in different types of galaxies, and conclude that red quiescent galaxies without star formation have favorable traversability. Compact elliptical galaxies and globular clusters could be "super-traversable", because stars are packed tightly together and there are minimal ISM hazards. Overall, if the ISM is the major hindrance to interstellar travel, galactic traversability increases with cosmic time as gas fractions and star formation decline. Traversability is a consideration in extragalactic surveys for the search for extraterrestrial intelligence (SETI).},
urldate = {2021-07-07},
journal = {arXiv e-prints},
author = {Lacki, Brian C.},
month = jun,
year = {2021},
keywords = {Astrophysics - Astrophysics of Galaxies, Physics - Popular Physics},
pages = {arXiv:2106.07739},
}The Evolution of the IR Luminosity Function and Dust-obscured Star Formation in the Last 13 Billion Years. Zavala, J. A., Casey, C. M., Manning, S. M., Aravena, M., Bethermin, M., Caputi, K. I., Clements, D. L., da Cunha, E., Drew, P., Finkelstein, S. L., Fujimoto, S., Hayward, C., Hodge, J., Kartaltepe, J. S., Knudsen, K., Koekemoer, A. M., Long, A. S., Magdis, G. E., Man, A. W. S., Popping, G., Sanders, D., Scoville, N., Sheth, K., Staguhn, J., Toft, S., Treister, E., Vieira, J. D., & Yun, M. S. arXiv e-prints, 2101:arXiv:2101.04734, January, 2021.
Paper abstract bibtex
Paper abstract bibtex We present the first results from the 2mm Mapping Obscuration to Reionization (MORA) survey, the largest ALMA contiguous blank-field survey to-date with a total area of 184 sq. arcmin and the only at 2mm to search for dusty star-forming galaxies (DSFGs). We use the 13 sources detected above 5sigma to estimate the first ALMA galaxy number counts at this wavelength. These number counts are then combined with the state-of-the-art galaxy number counts at 1.2mm and 3mm and with a backward evolution model to place constraints on the evolution of the IR luminosity function and dust-obscured star formation in the last 13 billion years. Our results suggest a steep redshift evolution on the space density of DSFGs and confirm the flattening of the IR luminosity function at faint luminosities, with a slope of \${\textbackslash}alpha_\{LF\} = -0.42{\textasciicircum}\{+0.02\}_\{-0.04\}\$. We conclude that the dust-obscured component, which peaks at z=2-2.5, has dominated the cosmic history of star formation for the past \textasciitilde12 billion years, back to z\textasciitilde4. At z=5, the dust-obscured star formation is estimated to be \textasciitilde35% of the total star formation rate density and decreases to 25%-20% at z=6-7, implying a minor contribution of dust-enshrouded star formation in the first billion years of the Universe. With the dust-obscured star formation history constrained up to the end of the epoch of reionization, our results provide a benchmark to test galaxy formation models, to study the galaxy mass assembly history, and to understand the dust and metal enrichment of the Universe at early times.
@article{zavala_evolution_2021,
title = {The {Evolution} of the {IR} {Luminosity} {Function} and {Dust}-obscured {Star} {Formation} in the {Last} 13 {Billion} {Years}},
volume = {2101},
url = {http://adsabs.harvard.edu/abs/2021arXiv210104734Z},
abstract = {We present the first results from the 2mm Mapping Obscuration to
Reionization (MORA) survey, the largest ALMA contiguous blank-field
survey to-date with a total area of 184 sq. arcmin and the only at 2mm
to search for dusty star-forming galaxies (DSFGs). We use the 13 sources
detected above 5sigma to estimate the first ALMA galaxy number counts at
this wavelength. These number counts are then combined with the
state-of-the-art galaxy number counts at 1.2mm and 3mm and with a
backward evolution model to place constraints on the evolution of the IR
luminosity function and dust-obscured star formation in the last 13
billion years. Our results suggest a steep redshift evolution on the
space density of DSFGs and confirm the flattening of the IR luminosity
function at faint luminosities, with a slope of \${\textbackslash}alpha\_\{LF\} =
-0.42{\textasciicircum}\{+0.02\}\_\{-0.04\}\$. We conclude that the dust-obscured component,
which peaks at z=2-2.5, has dominated the cosmic history of star
formation for the past {\textasciitilde}12 billion years, back to z{\textasciitilde}4. At z=5, the
dust-obscured star formation is estimated to be {\textasciitilde}35\% of the total star
formation rate density and decreases to 25\%-20\% at z=6-7, implying a
minor contribution of dust-enshrouded star formation in the first
billion years of the Universe. With the dust-obscured star formation
history constrained up to the end of the epoch of reionization, our
results provide a benchmark to test galaxy formation models, to study
the galaxy mass assembly history, and to understand the dust and metal
enrichment of the Universe at early times.},
urldate = {2021-02-03},
journal = {arXiv e-prints},
author = {Zavala, J. A. and Casey, C. M. and Manning, S. M. and Aravena, M. and Bethermin, M. and Caputi, K. I. and Clements, D. L. and da Cunha, E. and Drew, P. and Finkelstein, S. L. and Fujimoto, S. and Hayward, C. and Hodge, J. and Kartaltepe, J. S. and Knudsen, K. and Koekemoer, A. M. and Long, A. S. and Magdis, G. E. and Man, A. W. S. and Popping, G. and Sanders, D. and Scoville, N. and Sheth, K. and Staguhn, J. and Toft, S. and Treister, E. and Vieira, J. D. and Yun, M. S.},
month = jan,
year = {2021},
keywords = {Astrophysics - Astrophysics of Galaxies},
pages = {arXiv:2101.04734},
}The THESAN project: properties of the intergalactic medium and its connection to Reionization-era galaxies. Garaldi, E., Kannan, R., Smith, A., Springel, V., Pakmor, R., Vogelsberger, M., & Hernquist, L. Technical Report October, 2021. Publication Title: arXiv e-prints ADS Bibcode: 2021arXiv211001628G Type: article
Paper abstract bibtex
Paper abstract bibtex The high-redshift intergalactic medium (IGM) and the primeval galaxy population are rapidly becoming the new frontier of extra-galactic astronomy. We investigate the IGM properties and their connection to galaxies at \$z{\textbackslash}geq5.5\$ under different assumptions for the ionizing photon escape and the nature of dark matter, employing our novel THESAN radiation-hydrodynamical simulation suite, designed to provide a comprehensive picture of the emergence of galaxies in a full reionization context. Our simulations have realistic `late' reionization histories, match available constraints on global IGM properties and reproduce the recently-observed rapid evolution of the mean free path of ionizing photons. We additionally examine high-z Lyman-\${\textbackslash}alpha\$ transmission. The optical depth evolution is consistent with data, and its distribution suggests an even-later reionization than simulated, although with a strong sensitivity to the source model. We show that the effects of these two unknowns can be disentangled by characterising the spectral shape and separation of Lyman-\${\textbackslash}alpha\$ transmission regions, opening up the possibility to observationally constrain both. For the first time in simulations, THESAN reproduces the modulation of the Lyman-\${\textbackslash}alpha\$ flux as a function of galaxy distance, demonstrating the power of coupling a realistic galaxy formation model with proper radiation-hydrodynamics. We find this feature to be extremely sensitive on the timing of reionization, while being relatively insensitive to the source model. Overall, THESAN produces a realistic IGM and galaxy population, providing a robust framework for future analysis of the high-z Universe.
@techreport{garaldi_thesan_2021,
title = {The {THESAN} project: properties of the intergalactic medium and its connection to {Reionization}-era galaxies},
shorttitle = {The {THESAN} project},
url = {https://ui.adsabs.harvard.edu/abs/2021arXiv211001628G},
abstract = {The high-redshift intergalactic medium (IGM) and the primeval galaxy population are rapidly becoming the new frontier of extra-galactic astronomy. We investigate the IGM properties and their connection to galaxies at \$z{\textbackslash}geq5.5\$ under different assumptions for the ionizing photon escape and the nature of dark matter, employing our novel THESAN radiation-hydrodynamical simulation suite, designed to provide a comprehensive picture of the emergence of galaxies in a full reionization context. Our simulations have realistic `late' reionization histories, match available constraints on global IGM properties and reproduce the recently-observed rapid evolution of the mean free path of ionizing photons. We additionally examine high-z Lyman-\${\textbackslash}alpha\$ transmission. The optical depth evolution is consistent with data, and its distribution suggests an even-later reionization than simulated, although with a strong sensitivity to the source model. We show that the effects of these two unknowns can be disentangled by characterising the spectral shape and separation of Lyman-\${\textbackslash}alpha\$ transmission regions, opening up the possibility to observationally constrain both. For the first time in simulations, THESAN reproduces the modulation of the Lyman-\${\textbackslash}alpha\$ flux as a function of galaxy distance, demonstrating the power of coupling a realistic galaxy formation model with proper radiation-hydrodynamics. We find this feature to be extremely sensitive on the timing of reionization, while being relatively insensitive to the source model. Overall, THESAN produces a realistic IGM and galaxy population, providing a robust framework for future analysis of the high-z Universe.},
urldate = {2021-10-08},
author = {Garaldi, Enrico and Kannan, Rahul and Smith, Aaron and Springel, Volker and Pakmor, Rüdiger and Vogelsberger, Mark and Hernquist, Lars},
month = oct,
year = {2021},
note = {Publication Title: arXiv e-prints
ADS Bibcode: 2021arXiv211001628G
Type: article},
keywords = {Astrophysics - Astrophysics of Galaxies, Astrophysics - Cosmology and Nongalactic Astrophysics},
}A Nascent Tidal Dwarf Galaxy Forming within the Northern H I Streamer of M82. Pasha, I., Lokhorst, D., van Dokkum , P. G., Chen, S., Abraham, R., Greco, J., Danieli, S., Miller, T., Lippitt, E., Polzin, A., Shen, Z., Keim, M. A., Liu, Q., Merritt, A., & Zhang, J. \apjl, 923(2):L21, December, 2021.
doi bibtex
doi bibtex
@ARTICLE{2021ApJ...923L..21P,
author = {{Pasha}, Imad and {Lokhorst}, Deborah and {van Dokkum}, Pieter G. and {Chen}, Seery and {Abraham}, Roberto and {Greco}, Johnny and {Danieli}, Shany and {Miller}, Tim and {Lippitt}, Erin and {Polzin}, Ava and {Shen}, Zili and {Keim}, Michael A. and {Liu}, Qing and {Merritt}, Allison and {Zhang}, Jielai},
title = "{A Nascent Tidal Dwarf Galaxy Forming within the Northern H I Streamer of M82}",
journal = {\apjl},
keywords = {1701, 600, 1088, 691, 416, 1570, 2029, Astrophysics - Astrophysics of Galaxies},
year = 2021,
month = dec,
volume = {923},
number = {2},
eid = {L21},
pages = {L21},
doi = {10.3847/2041-8213/ac3ca6},
archivePrefix = {arXiv},
eprint = {2112.07052},
primaryClass = {astro-ph.GA},
adsurl = {https://ui.adsabs.harvard.edu/abs/2021ApJ...923L..21P},
adsnote = {Provided by the SAO/NASA Astrophysics Data System}
}DETECTIFz galaxy groups in the REFINE survey – 1. Group detection and quenched fraction evolution at \$z {\textless} 2.5\$. Sarron, F. & Conselice, C. J arXiv e-prints, June, 2021.
Paper abstract bibtex
Paper abstract bibtex We use a large K-selected sample of 299,961 galaxies from the REFINE survey, consisting of a combination of data from three of the deepest near-infrared surveys: UKIDSS UDS, COSMOS/UltraVISTA and CFHTLS-D1/VIDEO, that were homogeneously reduced to obtain photometric redshifts and stellar masses. We detect 2588 candidate galaxy groups up to \$z=3.15\$ at \$S/N{\textgreater}1.5\$. We build a very pure (\${\textgreater}90{\textbackslash}%\$) sample of 448 candidate groups up to \$z=2.5\$ and study some of their properties. Cluster detection is done using the DElaunay TEssellation ClusTer IdentiFication with photo-z (DETECTIFz) algorithm that we describe. This new group finder algorithm uses the joint probability distribution functions (PDF) of redshift and stellar-mass of galaxies to detect groups as stellar-mass overdensities in overlapping redshift slices, where density is traced using Monte Carlo realisation of the Delaunay Tessellation Field Estimator (DTFE). We compute the algorithm selection function using mock galaxy catalogues taken from cosmological N-body simulation lightcones. Based on these simulations, we reach a completeness of \${\textbackslash}sim80{\textbackslash}%\$ for clusters (\$M_\{200\}{\textgreater}10{\textasciicircum}\{14\} M_\{{\textbackslash}odot\}\$) at a purity of \${\textbackslash}sim90{\textbackslash}%\$ at \$z{\textless}2.5\$. Using our 403 most massive candidate groups, we constrain the redshift evolution of the group galaxy quenched fraction at \$0.12{\textbackslash}le z{\textless}2.32\$, for galaxies with \$10.25 {\textless} {\textbackslash}log M_{\textbackslash}star/M_\{{\textbackslash}odot\} {\textless} 11\$ in \$0.5{\textbackslash}times R_\{200\}\$. We find that the quenched fraction in group cores is higher than in the field in the full redshift range considered, the difference growing with decreasing redshift. This indicates either more efficient quenching mechanisms in group cores at lower redshift or pre-processing by cosmic filaments.
@article{sarron_detectifz_2021,
title = {{DETECTIFz} galaxy groups in the {REFINE} survey -- 1. {Group} detection and quenched fraction evolution at \$z {\textless} 2.5\$},
url = {https://ui.adsabs.harvard.edu/abs/2021arXiv210613101S},
abstract = {We use a large K-selected sample of 299,961 galaxies from the REFINE survey, consisting of a combination of data from three of the deepest near-infrared surveys: UKIDSS UDS, COSMOS/UltraVISTA and CFHTLS-D1/VIDEO, that were homogeneously reduced to obtain photometric redshifts and stellar masses. We detect 2588 candidate galaxy groups up to \$z=3.15\$ at \$S/N{\textgreater}1.5\$. We build a very pure (\${\textgreater}90{\textbackslash}\%\$) sample of 448 candidate groups up to \$z=2.5\$ and study some of their properties. Cluster detection is done using the DElaunay TEssellation ClusTer IdentiFication with photo-z (DETECTIFz) algorithm that we describe. This new group finder algorithm uses the joint probability distribution functions (PDF) of redshift and stellar-mass of galaxies to detect groups as stellar-mass overdensities in overlapping redshift slices, where density is traced using Monte Carlo realisation of the Delaunay Tessellation Field Estimator (DTFE). We compute the algorithm selection function using mock galaxy catalogues taken from cosmological N-body simulation lightcones. Based on these simulations, we reach a completeness of \${\textbackslash}sim80{\textbackslash}\%\$ for clusters (\$M\_\{200\}{\textgreater}10{\textasciicircum}\{14\} M\_\{{\textbackslash}odot\}\$) at a purity of \${\textbackslash}sim90{\textbackslash}\%\$ at \$z{\textless}2.5\$. Using our 403 most massive candidate groups, we constrain the redshift evolution of the group galaxy quenched fraction at \$0.12{\textbackslash}le z{\textless}2.32\$, for galaxies with \$10.25 {\textless} {\textbackslash}log M\_{\textbackslash}star/M\_\{{\textbackslash}odot\} {\textless} 11\$ in \$0.5{\textbackslash}times R\_\{200\}\$. We find that the quenched fraction in group cores is higher than in the field in the full redshift range considered, the difference growing with decreasing redshift. This indicates either more efficient quenching mechanisms in group cores at lower redshift or pre-processing by cosmic filaments.},
urldate = {2021-07-02},
journal = {arXiv e-prints},
author = {Sarron, Florian and Conselice, Christopher J},
month = jun,
year = {2021},
keywords = {Astrophysics - Astrophysics of Galaxies, Astrophysics - Cosmology and Nongalactic Astrophysics},
pages = {arXiv:2106.13101},
}Galaxy Formation and Reionization: Key Unknowns and Expected Breakthroughs by the James Webb Space Telescope. Robertson, B. E. arXiv:2110.13160 [astro-ph], October, 2021. arXiv: 2110.13160
Paper abstract bibtex
Paper abstract bibtex The scheduled launch of James Webb Space Telescope (JWST) in late 2021 marks a new start for studies of galaxy formation at high redshift z\textgreater\textasciitilde6 during the era of Cosmic Reionization. JWST can capture sensitive, high-resolution images and multi-object spectroscopy in the infrared that will transform our view of galaxy formation during the first billion years of cosmic history. This review summarizes our current knowledge of the role of galaxies in reionizing intergalactic hydrogen ahead of JWST, achieved through observations with Hubble Space Telescope and ground-based facilities including Keck, the Very Large Telescope, Subaru, and the Atacama Large Millimeter/Submillimeter Array. We identify outstanding questions in the field that JWST can address during its mission lifetime, including with the planned JWST Cycle 1 programs. (Abridged)
@article{robertson_galaxy_2021,
title = {Galaxy {Formation} and {Reionization}: {Key} {Unknowns} and {Expected} {Breakthroughs} by the {James} {Webb} {Space} {Telescope}},
shorttitle = {Galaxy {Formation} and {Reionization}},
url = {http://arxiv.org/abs/2110.13160},
abstract = {The scheduled launch of James Webb Space Telescope (JWST) in late 2021 marks a new start for studies of galaxy formation at high redshift z{\textgreater}{\textasciitilde}6 during the era of Cosmic Reionization. JWST can capture sensitive, high-resolution images and multi-object spectroscopy in the infrared that will transform our view of galaxy formation during the first billion years of cosmic history. This review summarizes our current knowledge of the role of galaxies in reionizing intergalactic hydrogen ahead of JWST, achieved through observations with Hubble Space Telescope and ground-based facilities including Keck, the Very Large Telescope, Subaru, and the Atacama Large Millimeter/Submillimeter Array. We identify outstanding questions in the field that JWST can address during its mission lifetime, including with the planned JWST Cycle 1 programs. (Abridged)},
urldate = {2021-11-09},
journal = {arXiv:2110.13160 [astro-ph]},
author = {Robertson, Brant E.},
month = oct,
year = {2021},
note = {arXiv: 2110.13160},
keywords = {Astrophysics - Astrophysics of Galaxies, Astrophysics - Cosmology and Nongalactic Astrophysics},
}Quiescent Ultra-diffuse galaxies in the field originating from backsplash orbits. Benavides, J. A., Sales, L. V., Abadi, M. G., Pillepich, A., Nelson, D., Marinacci, F., Cooper, M., Pakmor, R., Torrey, P., Vogelsberger, M., & Hernquist, L. Technical Report September, 2021. Publication Title: arXiv e-prints ADS Bibcode: 2021arXiv210901677B Type: article
Paper abstract bibtex
Paper abstract bibtex Ultra-diffuse galaxies (UDGs) are the lowest-surface brightness galaxies known, with typical stellar masses of dwarf galaxies but sizes similar to larger galaxies like the Milky Way. The reason for their extended sizes is debated, with suggested internal processes like angular momentum, feedback or mergers versus external mechanisms or a combination of both. Observationally, we know that UDGs are red and quiescent in groups and clusters while their counterparts in the field are blue and star-forming. This dichotomy suggests environmental effects as main culprit. However, this scenario is challenged by recent observations of isolated quiescent UDGs in the field. Here we use \${\textbackslash}Lambda\$CDM cosmological hydrodynamical simulation to show that isolated quenched UDGs are formed as backsplash galaxies that were once satellites of another galactic, group or cluster halo but are today a few Mpc away from them. These interactions, albeit brief, remove the gas and tidally strip the outskirts of the dark matter haloes of the now quenched seemingly-isolated UDGs, which are born as star-forming field UDGs occupying dwarf-mass dark matter haloes. Quiescent UDGs may therefore be found in non-negligible numbers in filaments and voids, bearing the mark of past interactions as stripped outer haloes devoid of dark matter and gas compared to dwarfs with similar stellar content.
@techreport{2021arXiv210901677B,
title = {Quiescent {Ultra}-diffuse galaxies in the field originating from backsplash orbits},
url = {https://ui.adsabs.harvard.edu/abs/2021arXiv210901677B},
abstract = {Ultra-diffuse galaxies (UDGs) are the lowest-surface brightness galaxies known, with typical stellar masses of dwarf galaxies but sizes similar to larger galaxies like the Milky Way. The reason for their extended sizes is debated, with suggested internal processes like angular momentum, feedback or mergers versus external mechanisms or a combination of both. Observationally, we know that UDGs are red and quiescent in groups and clusters while their counterparts in the field are blue and star-forming. This dichotomy suggests environmental effects as main culprit. However, this scenario is challenged by recent observations of isolated quiescent UDGs in the field. Here we use \${\textbackslash}Lambda\$CDM cosmological hydrodynamical simulation to show that isolated quenched UDGs are formed as backsplash galaxies that were once satellites of another galactic, group or cluster halo but are today a few Mpc away from them. These interactions, albeit brief, remove the gas and tidally strip the outskirts of the dark matter haloes of the now quenched seemingly-isolated UDGs, which are born as star-forming field UDGs occupying dwarf-mass dark matter haloes. Quiescent UDGs may therefore be found in non-negligible numbers in filaments and voids, bearing the mark of past interactions as stripped outer haloes devoid of dark matter and gas compared to dwarfs with similar stellar content.},
urldate = {2021-09-07},
author = {Benavides, José A. and Sales, Laura V. and Abadi, Mario. G. and Pillepich, Annalisa and Nelson, Dylan and Marinacci, Federico and Cooper, Michael and Pakmor, Ruediger and Torrey, Paul and Vogelsberger, Mark and Hernquist, Lars},
month = sep,
year = {2021},
note = {Publication Title: arXiv e-prints
ADS Bibcode: 2021arXiv210901677B
Type: article},
keywords = {Astrophysics - Astrophysics of Galaxies},
}The effects of binary stars on galaxies and metal-enriched gas during reionization. Doughty, C. C. & Finlator, K. M. arXiv e-prints, 2105:arXiv:2105.09972, May, 2021.
Paper abstract bibtex
Paper abstract bibtex Binary stars are abundant in nearby galaxies, but are typically unaccounted for in simulations of the high redshift Universe. Stellar population synthesis models that include the effects of binary evolution result in greater relative abundances of ionizing photons that could significantly affect the ambient ionizing background during the epoch of hydrogen reionization, additionally leading to differences in galaxy gas content and star formation. We use hydrodynamic cosmological simulations including in situ multifrequency radiative transfer to evaluate the effects of a high binary fraction in reionization-era galaxies on traits of the early intergalactic medium and the abundance of H I and He II ionizing photons. We further extend this to analyze the traits of enriched gas. In comparing metrics generated using a fiducial simulation assuming single stars with one incorporating a high binary fraction, we find that binary stars cause H I reionization to complete earlier and at an accelerated pace, while also increasing the abundances of high-ionization metals (C IV and Si IV) in simulated absorption spectra while reducing the abundance of low-ionization states (O I, Si II, and C II). However, through increased photoheating of galactic and circumgalactic gas, they simultaneously reduce the rate of star formation in low-mass galaxies, slowing the ongoing process of enrichment and suppressing their own ionizing background. This potentially contributes to a slower He II reionization process at \$z{\textbackslash}geq5\$, and further indicates that self-regulation of galaxies could be underestimated when neglecting binary stellar evolution.
@article{doughty_effects_2021,
title = {The effects of binary stars on galaxies and metal-enriched gas during reionization},
volume = {2105},
url = {http://adsabs.harvard.edu/abs/2021arXiv210509972D},
abstract = {Binary stars are abundant in nearby galaxies, but are typically
unaccounted for in simulations of the high redshift Universe. Stellar
population synthesis models that include the effects of binary evolution
result in greater relative abundances of ionizing photons that could
significantly affect the ambient ionizing background during the epoch of
hydrogen reionization, additionally leading to differences in galaxy gas
content and star formation. We use hydrodynamic cosmological simulations
including in situ multifrequency radiative transfer to evaluate the
effects of a high binary fraction in reionization-era galaxies on traits
of the early intergalactic medium and the abundance of H I and He II
ionizing photons. We further extend this to analyze the traits of
enriched gas. In comparing metrics generated using a fiducial simulation
assuming single stars with one incorporating a high binary fraction, we
find that binary stars cause H I reionization to complete earlier and at
an accelerated pace, while also increasing the abundances of
high-ionization metals (C IV and Si IV) in simulated absorption spectra
while reducing the abundance of low-ionization states (O I, Si II, and C
II). However, through increased photoheating of galactic and
circumgalactic gas, they simultaneously reduce the rate of star
formation in low-mass galaxies, slowing the ongoing process of
enrichment and suppressing their own ionizing background. This
potentially contributes to a slower He II reionization process at
\$z{\textbackslash}geq5\$, and further indicates that self-regulation of galaxies could
be underestimated when neglecting binary stellar evolution.},
urldate = {2021-06-04},
journal = {arXiv e-prints},
author = {Doughty, Caitlin C. and Finlator, Kristian M.},
month = may,
year = {2021},
keywords = {Astrophysics - Astrophysics of Galaxies, Astrophysics - Cosmology and Nongalactic Astrophysics},
pages = {arXiv:2105.09972},
}High-redshift quasars and their host galaxies II: multiphase gas and stellar kinematics. Lupi, A., Volonteri, M., Decarli, R., Bovino, S., & Silk, J. Technical Report September, 2021. Publication Title: arXiv e-prints ADS Bibcode: 2021arXiv210901679L Type: article
Paper abstract bibtex
Paper abstract bibtex Observations of \$z rsim 6\$ quasars provide information on the early phases of the most massive black holes (MBHs) and galaxies. Current observations at sub-mm wavelengths trace cold and warm gas, and future observations will extend information to other gas phases and the stellar properties. The goal of this study is to examine the gas life cycle in a \$z rsim 6\$ quasar: from accretion from the halo to the galaxy and all the way into the MBH, to how star formation and the MBH itself affect the gas properties. Using a very-high resolution cosmological zoom-in simulation of a \$z=7\$ quasar including state-of-the-art non-equilibrium chemistry, MBH formation, growth and feedback, we investigate the distribution of the different gas phases in the interstellar medium across cosmic time. We assess the morphological evolution of the quasar host using different tracers (star- or gas-based) and the thermodynamic distribution of the MBH accretion-driven outflows, finding that obscuration in the disc is mainly due to molecular gas, with the atomic component contributing at larger scales and/or above/below the disc plane. Moreover, our results also show that molecular outflows, if present, are more likely the result of gas being lifted near the MBH than production within the wind because of thermal instabilities. Finally, we also discuss how different gas phases can be employed to dynamically constrain the MBH mass, and argue that resolutions below \${\textbackslash}sim 100\$ pc yield unreliable estimates because of the strong contribution of the nuclear stellar component to the potential at larger scales.
@techreport{2021arXiv210901679L,
title = {High-redshift quasars and their host galaxies {II}: multiphase gas and stellar kinematics},
shorttitle = {High-redshift quasars and their host galaxies {II}},
url = {https://ui.adsabs.harvard.edu/abs/2021arXiv210901679L},
abstract = {Observations of \$z rsim 6\$ quasars provide information on the early phases of the most massive black holes (MBHs) and galaxies. Current observations at sub-mm wavelengths trace cold and warm gas, and future observations will extend information to other gas phases and the stellar properties. The goal of this study is to examine the gas life cycle in a \$z rsim 6\$ quasar: from accretion from the halo to the galaxy and all the way into the MBH, to how star formation and the MBH itself affect the gas properties. Using a very-high resolution cosmological zoom-in simulation of a \$z=7\$ quasar including state-of-the-art non-equilibrium chemistry, MBH formation, growth and feedback, we investigate the distribution of the different gas phases in the interstellar medium across cosmic time. We assess the morphological evolution of the quasar host using different tracers (star- or gas-based) and the thermodynamic distribution of the MBH accretion-driven outflows, finding that obscuration in the disc is mainly due to molecular gas, with the atomic component contributing at larger scales and/or above/below the disc plane. Moreover, our results also show that molecular outflows, if present, are more likely the result of gas being lifted near the MBH than production within the wind because of thermal instabilities. Finally, we also discuss how different gas phases can be employed to dynamically constrain the MBH mass, and argue that resolutions below \${\textbackslash}sim 100\$ pc yield unreliable estimates because of the strong contribution of the nuclear stellar component to the potential at larger scales.},
urldate = {2021-09-07},
author = {Lupi, Alessandro and Volonteri, Marta and Decarli, Roberto and Bovino, Stefano and Silk, Joseph},
month = sep,
year = {2021},
note = {Publication Title: arXiv e-prints
ADS Bibcode: 2021arXiv210901679L
Type: article},
keywords = {Astrophysics - Astrophysics of Galaxies, Astrophysics - Cosmology and Nongalactic Astrophysics},
}The ALPINE-ALMA [CII] survey: The contribution of major mergers to the galaxy mass assembly at z\textasciitilde5. Romano, M., Cassata, P., Morselli, L., Jones, G. C., Ginolfi, M., Zanella, A., Béthermin, M., Capak, P., Faisst, A., Le Fèvre, O., Schaerer, D., Silverman, J. D., Yan, L., Bardelli, S., Boquien, M., Cimatti, A., Dessauges-Zavadsky, M., Enia, A., Fujimoto, S., Gruppioni, C., Hathi, N. P., Ibar, E., Koekemoer, A. M., Lemaux, B. C., Rodighiero, G., Vergani, D., Zamorani, G., & Zucca, E. Technical Report July, 2021. Publication Title: arXiv e-prints ADS Bibcode: 2021arXiv210710856R Type: article
Paper abstract bibtex
Paper abstract bibtex Galaxy mergers are thought to be one of the main mechanisms of the mass assembly of galaxies. Recently, many works have suggested a possible increase in the fraction of major mergers in the early Universe, reviving the debate on which processes (e.g., cold accretion, star formation, mergers) most contribute to the mass build-up of galaxies through cosmic time. To estimate the importance of major mergers in this context, we make use of the new data collected by the ALMA Large Program to INvestigate [CII] at Early times (ALPINE), which observed the [CII] 158 \${\textbackslash}mu\$m emission line from a sample of 75 main-sequence star-forming galaxies at 4.4 \textless z \textless 5.9. We used, for the first time, the morpho-kinematic information provided by the [CII] emission to obtain the fraction of major mergers (\$f_\{MM\}\$) at z\textasciitilde5. By adopting different prescriptions for the merger timescales (\$T_\{MM\}\$), we converted this fraction into the merger rate per galaxy (\$R_\{MM\}\$) and per volume (\${\textbackslash}Gamma_\{MM\}\$). We then combined our results with those at lower redshifts from the literature, computing the cosmic evolution of the merger fraction. This is described by a rapid increase from z\textasciitilde0 to higher redshifts, a peak at z\textasciitilde3, and a slow decrease towards earlier epochs. Depending on the timescale prescription used, this fraction translates into a merger rate ranging between \textasciitilde0.1 and \textasciitilde4.0 Gyr\${\textasciicircum}\{-1\}\$ at z\textasciitilde5. Finally, we compare the specific star formation and star-formation rate density with the analogous quantities from major mergers. Our new ALPINE data reveal the presence of a significant merging activity in the early Universe. However, whether this population of mergers can provide a relevant contribution to the galaxy mass assembly at these redshifts and through the cosmic epochs is strongly dependent on the assumption of the merger timescale.
@techreport{2021arXiv210710856R,
title = {The {ALPINE}-{ALMA} [{CII}] survey: {The} contribution of major mergers to the galaxy mass assembly at z{\textasciitilde}5},
shorttitle = {The {ALPINE}-{ALMA} [{CII}] survey},
url = {https://ui.adsabs.harvard.edu/abs/2021arXiv210710856R},
abstract = {Galaxy mergers are thought to be one of the main mechanisms of the mass assembly of galaxies. Recently, many works have suggested a possible increase in the fraction of major mergers in the early Universe, reviving the debate on which processes (e.g., cold accretion, star formation, mergers) most contribute to the mass build-up of galaxies through cosmic time. To estimate the importance of major mergers in this context, we make use of the new data collected by the ALMA Large Program to INvestigate [CII] at Early times (ALPINE), which observed the [CII] 158 \${\textbackslash}mu\$m emission line from a sample of 75 main-sequence star-forming galaxies at 4.4 {\textless} z {\textless} 5.9. We used, for the first time, the morpho-kinematic information provided by the [CII] emission to obtain the fraction of major mergers (\$f\_\{MM\}\$) at z{\textasciitilde}5. By adopting different prescriptions for the merger timescales (\$T\_\{MM\}\$), we converted this fraction into the merger rate per galaxy (\$R\_\{MM\}\$) and per volume (\${\textbackslash}Gamma\_\{MM\}\$). We then combined our results with those at lower redshifts from the literature, computing the cosmic evolution of the merger fraction. This is described by a rapid increase from z{\textasciitilde}0 to higher redshifts, a peak at z{\textasciitilde}3, and a slow decrease towards earlier epochs. Depending on the timescale prescription used, this fraction translates into a merger rate ranging between {\textasciitilde}0.1 and {\textasciitilde}4.0 Gyr\${\textasciicircum}\{-1\}\$ at z{\textasciitilde}5. Finally, we compare the specific star formation and star-formation rate density with the analogous quantities from major mergers. Our new ALPINE data reveal the presence of a significant merging activity in the early Universe. However, whether this population of mergers can provide a relevant contribution to the galaxy mass assembly at these redshifts and through the cosmic epochs is strongly dependent on the assumption of the merger timescale.},
urldate = {2021-09-07},
author = {Romano, M. and Cassata, P. and Morselli, L. and Jones, G. C. and Ginolfi, M. and Zanella, A. and Béthermin, M. and Capak, P. and Faisst, A. and Le Fèvre, O. and Schaerer, D. and Silverman, J. D. and Yan, L. and Bardelli, S. and Boquien, M. and Cimatti, A. and Dessauges-Zavadsky, M. and Enia, A. and Fujimoto, S. and Gruppioni, C. and Hathi, N. P. and Ibar, E. and Koekemoer, A. M. and Lemaux, B. C. and Rodighiero, G. and Vergani, D. and Zamorani, G. and Zucca, E.},
month = jul,
year = {2021},
note = {Publication Title: arXiv e-prints
ADS Bibcode: 2021arXiv210710856R
Type: article},
keywords = {Astrophysics - Astrophysics of Galaxies},
}Spectroscopic observations of PHz G237.01+42.50: A galaxy protocluster at z=2.16 in the Cosmos field. Polletta, M., Soucail, G., Dole, H., Lehnert, M. D., Pointecouteau, E., Vietri, G., Scodeggio, M., Montier, L., Koyama, Y., Lagache, G., Frye, B. L., Cusano, F., & Fumana, M. Technical Report September, 2021. Publication Title: arXiv e-prints ADS Bibcode: 2021arXiv210904396P Type: article
Paper abstract bibtex
Paper abstract bibtex The Planck satellite has identified more than 2000 protocluster candidates with extreme star formation rates (SFRs). Here, we present the spectroscopic identification of a Planck-selected protocluster located in the Cosmos field, PHz G237.01+42.50 (G237). G237 contains a galaxy overdensity of 31 spectroscopically identified galaxies at z\textasciitilde2.16 (significant at 5.4 sigma) in a 10'x11' region. The overdensity contains two substructures or protoclusters at \textasciitilde2.16 and 2.195 with estimated halo masses at z=0 of \textasciitilde(5-6)x10\textasciicircum14 Msun. The overdensity total SFR, \textasciitilde4000 Msun/yr, is higher than predicted by simulations but much smaller than the SFR derived from the Planck data. The analysis of the Herschel data, in combination with the available ancillary data, shows that such a difference is due to an effect of source alignment along the line of sight that produces a 5 sigma overdensity of red Herschel sources in the field. We analyze the members' UV spectra and UV-far-infrared spectral energy distributions to derive their SFR, stellar mass, and metallicity. Galaxy members include blue star-forming galaxies and AGN with SFRs and stellar masses consistent with the main sequence. AGN, identified through optical spectroscopy or X-ray data, represent a significant fraction (20+/-10%) of all members of the protocluster at z=2.16, and they are powerful enough to produce radiative feedback. The core of this protocluster, besides being denser, includes members that are, on average, more massive and star-forming and contains a larger fraction of AGN and Herschel-detected galaxies than the full sample, suggesting an environmental effect on galaxy growth. A comparison between G237 and other protoclusters in the literature at similar redshifts reveals some common traits and differences that reflect both observational biases and a diversity in intrinsic properties that is not yet fully understood.
@techreport{polletta_spectroscopic_2021,
title = {Spectroscopic observations of {PHz} {G237}.01+42.50: {A} galaxy protocluster at z=2.16 in the {Cosmos} field},
shorttitle = {Spectroscopic observations of {PHz} {G237}.01+42.50},
url = {https://ui.adsabs.harvard.edu/abs/2021arXiv210904396P},
abstract = {The Planck satellite has identified more than 2000 protocluster candidates with extreme star formation rates (SFRs). Here, we present the spectroscopic identification of a Planck-selected protocluster located in the Cosmos field, PHz G237.01+42.50 (G237). G237 contains a galaxy overdensity of 31 spectroscopically identified galaxies at z{\textasciitilde}2.16 (significant at 5.4 sigma) in a 10'x11' region. The overdensity contains two substructures or protoclusters at {\textasciitilde}2.16 and 2.195 with estimated halo masses at z=0 of {\textasciitilde}(5-6)x10{\textasciicircum}14 Msun. The overdensity total SFR, {\textasciitilde}4000 Msun/yr, is higher than predicted by simulations but much smaller than the SFR derived from the Planck data. The analysis of the Herschel data, in combination with the available ancillary data, shows that such a difference is due to an effect of source alignment along the line of sight that produces a 5 sigma overdensity of red Herschel sources in the field. We analyze the members' UV spectra and UV-far-infrared spectral energy distributions to derive their SFR, stellar mass, and metallicity. Galaxy members include blue star-forming galaxies and AGN with SFRs and stellar masses consistent with the main sequence. AGN, identified through optical spectroscopy or X-ray data, represent a significant fraction (20+/-10\%) of all members of the protocluster at z=2.16, and they are powerful enough to produce radiative feedback. The core of this protocluster, besides being denser, includes members that are, on average, more massive and star-forming and contains a larger fraction of AGN and Herschel-detected galaxies than the full sample, suggesting an environmental effect on galaxy growth. A comparison between G237 and other protoclusters in the literature at similar redshifts reveals some common traits and differences that reflect both observational biases and a diversity in intrinsic properties that is not yet fully understood.},
urldate = {2021-10-14},
author = {Polletta, M. and Soucail, G. and Dole, H. and Lehnert, M. D. and Pointecouteau, E. and Vietri, G. and Scodeggio, M. and Montier, L. and Koyama, Y. and Lagache, G. and Frye, B. L. and Cusano, F. and Fumana, M.},
month = sep,
year = {2021},
note = {Publication Title: arXiv e-prints
ADS Bibcode: 2021arXiv210904396P
Type: article},
keywords = {Astrophysics - Astrophysics of Galaxies, Astrophysics - Cosmology and Nongalactic Astrophysics},
}Hierarchical fragmentation in high redshift galaxies revealed by hydrodynamical simulations. Faure, B., Bournaud, F., Fensch, J., Daddi, E., Behrendt, M., Burkert, A., & Richard, J. arXiv e-prints, 2101:arXiv:2101.11013, January, 2021.
Paper abstract bibtex
Paper abstract bibtex High-redshift star-forming galaxies have very different morphologies compared to nearby ones. Indeed, they are often dominated by bright star-forming structures of masses up to \$10{\textasciicircum}\{8-9\}\$ \${\textbackslash}mathrm\{M\}_{\textbackslash}odot\$ dubbed «giant clumps». However, recent observations questioned this result by showing only low-mass structures or no structure at all. We use Adaptative Mesh Refinement hydrodynamical simulations of galaxies with parsec-scale resolution to study the formation of structures inside clumpy high-redshift galaxies. We show that in very gas-rich galaxies star formation occurs in small gas clusters with masses below \$10{\textasciicircum}\{7-8\}\$ \${\textbackslash}mathrm\{M\}_{\textbackslash}odot\$ that are themselves located inside giant complexes with masses up to \$10{\textasciicircum}8\$ and sometimes \$10{\textasciicircum}9\$ \${\textbackslash}mathrm\{M\}_{\textbackslash}odot\$. Those massive structures are similar in mass and size to the giant clumps observed in imaging surveys, in particular with the Hubble Space Telescope. Using mock observations of simulated galaxies, we show that at very high resolution with instruments like the Atacama Large Millimeter Array or through gravitational lensing, only low-mass structures are likely to be detected, and their gathering into giant complexes might be missed. This leads to the non-detection of the giant clumps and therefore introduces a bias in the detection of these structures. We show that the simulated giant clumps can be gravitationally bound even when undetected in mocks representative for ALMA observations and HST observations of lensed galaxies. We then compare the top-down fragmentation of an initially warm disc and the bottom-up fragmentation of an initially cold disc to show that the process of formation of the clumps does not impact their physical properties.
@article{faure_hierarchical_2021,
title = {Hierarchical fragmentation in high redshift galaxies revealed by hydrodynamical simulations},
volume = {2101},
url = {http://adsabs.harvard.edu/abs/2021arXiv210111013F},
abstract = {High-redshift star-forming galaxies have very different morphologies
compared to nearby ones. Indeed, they are often dominated by bright
star-forming structures of masses up to \$10{\textasciicircum}\{8-9\}\$ \${\textbackslash}mathrm\{M\}\_{\textbackslash}odot\$
dubbed «giant clumps». However, recent observations
questioned this result by showing only low-mass structures or no
structure at all. We use Adaptative Mesh Refinement hydrodynamical
simulations of galaxies with parsec-scale resolution to study the
formation of structures inside clumpy high-redshift galaxies. We show
that in very gas-rich galaxies star formation occurs in small gas
clusters with masses below \$10{\textasciicircum}\{7-8\}\$ \${\textbackslash}mathrm\{M\}\_{\textbackslash}odot\$ that are
themselves located inside giant complexes with masses up to \$10{\textasciicircum}8\$ and
sometimes \$10{\textasciicircum}9\$ \${\textbackslash}mathrm\{M\}\_{\textbackslash}odot\$. Those massive structures are
similar in mass and size to the giant clumps observed in imaging
surveys, in particular with the Hubble Space Telescope. Using mock
observations of simulated galaxies, we show that at very high resolution
with instruments like the Atacama Large Millimeter Array or through
gravitational lensing, only low-mass structures are likely to be
detected, and their gathering into giant complexes might be missed. This
leads to the non-detection of the giant clumps and therefore introduces
a bias in the detection of these structures. We show that the simulated
giant clumps can be gravitationally bound even when undetected in mocks
representative for ALMA observations and HST observations of lensed
galaxies. We then compare the top-down fragmentation of an initially
warm disc and the bottom-up fragmentation of an initially cold disc to
show that the process of formation of the clumps does not impact their
physical properties.},
urldate = {2021-02-08},
journal = {arXiv e-prints},
author = {Faure, Baptiste and Bournaud, Frédéric and Fensch, Jérémy and Daddi, Emanuele and Behrendt, Manuel and Burkert, Andreas and Richard, Johan},
month = jan,
year = {2021},
keywords = {Astrophysics - Astrophysics of Galaxies},
pages = {arXiv:2101.11013},
}On the Impact of Inclination-Dependent Attenuation on Derived Star-Formation Histories: Results from Disk Galaxies in the GOODS Fields. Doore, K., Eufrasio, R. T., Lehmer, B. D., Monson, E. B., Basu-Zych, A., Garofali, K., & Ptak, A. arXiv:2109.05039 [astro-ph], September, 2021. arXiv: 2109.05039
Paper abstract bibtex
Paper abstract bibtex We develop and implement an inclination-dependent attenuation prescription for spectral energy distribution (SED) fitting and study its impact on derived star-formation histories. We apply our prescription within the SED fitting code Lightning to a clean sample of 82, z = 0.21-1.35 disk-dominated galaxies in the Great Observatories Origins Deep Survey (GOODS) North and South fields. To compare our inclination-dependent attenuation prescription with more traditional fitting prescriptions, we also fit the SEDs with the inclination-independent Calzetti et al. (2000) attenuation curve. From this comparison, we find that fits to a subset of 58, z \textless 0.7 galaxies in our sample, utilizing the Calzetti et al. (2000) prescription, recover similar trends with inclination as the inclination-dependent fits for the FUV-band attenuation and recent star-formation rates. However, we find a difference between prescriptions in the optical attenuation (AV) that is strongly correlated with inclination (p-value \textless 10\textasciicircum-10). For more face-on galaxies, with i \textless 50 deg, (edge-on, i = 90 deg), the average derived AV is 0.30 +/- 0.10 magnitudes lower (0.55 +/- 0.15 magnitudes higher) for the inclination-dependent model compared to traditional methods. Further, the ratio of stellar masses between prescriptions also has a significant (p-value \textless 10\textasciicircum-2) trend with inclination. For i = 0-65 deg, stellar masses are systematically consistent between fits, with log(Mstar_inc/Mstar_Calzetti) = -0.05 +/- 0.03 dex, and scatter of 0.11 dex. However, for i = 80-90 deg, derived stellar masses are lower for the Calzetti et al. (2000) fits by an average factor of 0.17 +/- 0.02 dex, and scatter of 0.13 dex. Therefore, these results suggest that SED fitting assuming the Calzetti et al. (2000) attenuation law potentially underestimates stellar masses in highly inclined disk-dominated galaxies.
@article{doore_impact_2021,
title = {On the {Impact} of {Inclination}-{Dependent} {Attenuation} on {Derived} {Star}-{Formation} {Histories}: {Results} from {Disk} {Galaxies} in the {GOODS} {Fields}},
shorttitle = {On the {Impact} of {Inclination}-{Dependent} {Attenuation} on {Derived} {Star}-{Formation} {Histories}},
url = {http://arxiv.org/abs/2109.05039},
abstract = {We develop and implement an inclination-dependent attenuation prescription for spectral energy distribution (SED) fitting and study its impact on derived star-formation histories. We apply our prescription within the SED fitting code Lightning to a clean sample of 82, z = 0.21-1.35 disk-dominated galaxies in the Great Observatories Origins Deep Survey (GOODS) North and South fields. To compare our inclination-dependent attenuation prescription with more traditional fitting prescriptions, we also fit the SEDs with the inclination-independent Calzetti et al. (2000) attenuation curve. From this comparison, we find that fits to a subset of 58, z {\textless} 0.7 galaxies in our sample, utilizing the Calzetti et al. (2000) prescription, recover similar trends with inclination as the inclination-dependent fits for the FUV-band attenuation and recent star-formation rates. However, we find a difference between prescriptions in the optical attenuation (AV) that is strongly correlated with inclination (p-value {\textless} 10{\textasciicircum}-10). For more face-on galaxies, with i {\textless} 50 deg, (edge-on, i = 90 deg), the average derived AV is 0.30 +/- 0.10 magnitudes lower (0.55 +/- 0.15 magnitudes higher) for the inclination-dependent model compared to traditional methods. Further, the ratio of stellar masses between prescriptions also has a significant (p-value {\textless} 10{\textasciicircum}-2) trend with inclination. For i = 0-65 deg, stellar masses are systematically consistent between fits, with log(Mstar\_inc/Mstar\_Calzetti) = -0.05 +/- 0.03 dex, and scatter of 0.11 dex. However, for i = 80-90 deg, derived stellar masses are lower for the Calzetti et al. (2000) fits by an average factor of 0.17 +/- 0.02 dex, and scatter of 0.13 dex. Therefore, these results suggest that SED fitting assuming the Calzetti et al. (2000) attenuation law potentially underestimates stellar masses in highly inclined disk-dominated galaxies.},
urldate = {2021-10-25},
journal = {arXiv:2109.05039 [astro-ph]},
author = {Doore, Keith and Eufrasio, Rafael T. and Lehmer, Bret D. and Monson, Erik B. and Basu-Zych, Antara and Garofali, Kristen and Ptak, Andrew},
month = sep,
year = {2021},
note = {arXiv: 2109.05039},
keywords = {Astrophysics - Astrophysics of Galaxies},
}A New Census of the 0.2\textless z \textless3.0 Universe, Part II: The Star-Forming Sequence. Leja, J., Speagle, J. S., Ting, Y., Johnson, B. D., Conroy, C., Whitaker, K. E., Nelson, E. J., van Dokkum, P., & Franx, M. arXiv:2110.04314 [astro-ph], October, 2021. arXiv: 2110.04314
Paper abstract bibtex
Paper abstract bibtex We use the panchromatic SED-fitting code Prospector to measure the galaxy logM\${\textasciicircum}*\$-logSFR relationship (the `star-forming sequence') across \$0.2 {\textless} z {\textless} 3.0\$ using the COSMOS-2015 and 3D-HST UV-IR photometric catalogs. We demonstrate that the chosen method of identifying star-forming galaxies introduces a systematic uncertainty in the inferred normalization and width of the star-forming sequence, peaking for massive galaxies at \${\textbackslash}sim 0.5\$ dex and \${\textbackslash}sim0.2\$ dex respectively. To avoid this systematic, we instead parameterize the density of the full galaxy population in the logM\${\textasciicircum}*\$-logSFR-redshift plane using a flexible neural network known as a normalizing flow. The resulting star-forming sequence has a low-mass slope near unity and a much flatter slope at higher masses, with a normalization \$0.2-0.5\$ dex lower than typical inferences in the literature. We show this difference is due to the sophistication of the Prospector stellar populations modeling: the nonparametric star formation histories naturally produce higher masses while the combination of individualized metallicity, dust, and star formation history constraints produce lower star formation rates than typical UV+IR formulae. We introduce a simple formalism to understand the difference between SFRs inferred from spectral energy distribution fitting and standard template-based approaches such as UV+IR SFRs. Finally, we demonstrate the inferred star-forming sequence is consistent with predictions from theoretical models of galaxy formation, resolving a long-standing \${\textbackslash}sim0.2-0.5\$ dex offset with observations at \$0.5{\textless}z{\textless}3\$. The fully trained normalizing flow including a nonparametric description of \${\textbackslash}rho({\textbackslash}log\{{\textbackslash}rm M\}{\textasciicircum}*,{\textbackslash}log\{{\textbackslash}rm SFR\},z)\$ is made available online to facilitate straightforward comparisons with future work.
@article{leja_new_2021,
title = {A {New} {Census} of the 0.2{\textless} z {\textless}3.0 {Universe}, {Part} {II}: {The} {Star}-{Forming} {Sequence}},
shorttitle = {A {New} {Census} of the 0.2{\textless} z {\textless}3.0 {Universe}, {Part} {II}},
url = {http://arxiv.org/abs/2110.04314},
abstract = {We use the panchromatic SED-fitting code Prospector to measure the galaxy logM\${\textasciicircum}*\$-logSFR relationship (the `star-forming sequence') across \$0.2 {\textless} z {\textless} 3.0\$ using the COSMOS-2015 and 3D-HST UV-IR photometric catalogs. We demonstrate that the chosen method of identifying star-forming galaxies introduces a systematic uncertainty in the inferred normalization and width of the star-forming sequence, peaking for massive galaxies at \${\textbackslash}sim 0.5\$ dex and \${\textbackslash}sim0.2\$ dex respectively. To avoid this systematic, we instead parameterize the density of the full galaxy population in the logM\${\textasciicircum}*\$-logSFR-redshift plane using a flexible neural network known as a normalizing flow. The resulting star-forming sequence has a low-mass slope near unity and a much flatter slope at higher masses, with a normalization \$0.2-0.5\$ dex lower than typical inferences in the literature. We show this difference is due to the sophistication of the Prospector stellar populations modeling: the nonparametric star formation histories naturally produce higher masses while the combination of individualized metallicity, dust, and star formation history constraints produce lower star formation rates than typical UV+IR formulae. We introduce a simple formalism to understand the difference between SFRs inferred from spectral energy distribution fitting and standard template-based approaches such as UV+IR SFRs. Finally, we demonstrate the inferred star-forming sequence is consistent with predictions from theoretical models of galaxy formation, resolving a long-standing \${\textbackslash}sim0.2-0.5\$ dex offset with observations at \$0.5{\textless}z{\textless}3\$. The fully trained normalizing flow including a nonparametric description of \${\textbackslash}rho({\textbackslash}log\{{\textbackslash}rm M\}{\textasciicircum}*,{\textbackslash}log\{{\textbackslash}rm SFR\},z)\$ is made available online to facilitate straightforward comparisons with future work.},
urldate = {2021-10-25},
journal = {arXiv:2110.04314 [astro-ph]},
author = {Leja, Joel and Speagle, Joshua S. and Ting, Yuan-Sen and Johnson, Benjamin D. and Conroy, Charlie and Whitaker, Katherine E. and Nelson, Erica J. and van Dokkum, Pieter and Franx, Marijn},
month = oct,
year = {2021},
note = {arXiv: 2110.04314},
keywords = {Astrophysics - Astrophysics of Galaxies},
}High resolution spectral imaging of CO(7-6), [CI](2-1) and continuum of three high-z lensed dusty star-forming galaxies using ALMA. Gururajan, G., Béthermin, M., Theulé, P., Spilker, J. S., Aravena, M., Archipley, M. A., Chapman, S. C., DeBreuck, C., Gonzalez, A., Hayward, C. C., Hezaveh, Y., Hill, R., Jarugula, S., Litke, K. C., Malkan, M., Marrone, D., Narayanan, D., Phadke, K. A., Reuter, C., Vieira, J., Vizgan, D., & Weiß, A. Technical Report September, 2021. Publication Title: arXiv e-prints ADS Bibcode: 2021arXiv210903450G Type: article
Paper abstract bibtex
Paper abstract bibtex High-redshift dusty star-forming galaxies with very high star formation rates (500 – 3000 M\$_{\textbackslash}odot\$ yr\${\textasciicircum}\{-1\}\$) are key to understanding the formation of the most extreme galaxies in the early Universe. Characterising the gas reservoir of these systems can reveal the driving factor behind the high star formation. Using molecular gas tracers like high-J CO lines, neutral carbon lines and the dust continuum, we can estimate the gas density and radiation field intensity in their interstellar medium. In this paper, we present high resolution(\${\textbackslash}sim\$0.4") observations of CO(7-6), [CI](2-1) and dust continuum of 3 lensed galaxies from the SPT-SMG sample at z\${\textbackslash}sim\$3 with the Atacama Large Millimeter/submillimeter Array. Our sources have high intrinsic star-formation rates (\textgreater850 M\$_{\textbackslash}odot\$ yr\${\textasciicircum}\{-1\}\$) and rather short depletion timescales (\textless100 Myr). Based on the \${\textbackslash}rm L_\{[{\textbackslash}rm CI](2-1)\}/ {\textbackslash}rm L_\{{\textbackslash}rm CO(7-6)\}\$ and \${\textbackslash}rm L_\{[{\textbackslash}rm CI](2-1)\}/{\textbackslash}rm L_\{{\textbackslash}rm IR\}\$ ratios, our sample galaxies exhibit higher radiation field intensity compared to other submillimetre galaxies but have similar gas densities. We perform visibility-based lens modelling on these objects to reconstruct the kinematics in the source plane. We find that the cold gas masses of the sources are compatible with simple dynamical mass estimates using ULIRG-like values of the CO-H\$_2\$ conversion factor \${\textbackslash}alpha_\{{\textbackslash}rm CO\}\$ but not Milky Way-like values. We find diverse source kinematics in our sample: SPT0103-45 and SPT2147-50 are likely rotating disks while SPT2357-51 is a probable major merger. The analysis presented in the paper could be extended to a larger sample to determine better statistics of morphologies and interstellar medium properties of high-z dusty star-forming galaxies.
@techreport{gururajan_high_2021,
title = {High resolution spectral imaging of {CO}(7-6), [{CI}](2-1) and continuum of three high-z lensed dusty star-forming galaxies using {ALMA}},
url = {https://ui.adsabs.harvard.edu/abs/2021arXiv210903450G},
abstract = {High-redshift dusty star-forming galaxies with very high star formation rates (500 -- 3000 M\$\_{\textbackslash}odot\$ yr\${\textasciicircum}\{-1\}\$) are key to understanding the formation of the most extreme galaxies in the early Universe. Characterising the gas reservoir of these systems can reveal the driving factor behind the high star formation. Using molecular gas tracers like high-J CO lines, neutral carbon lines and the dust continuum, we can estimate the gas density and radiation field intensity in their interstellar medium. In this paper, we present high resolution(\${\textbackslash}sim\$0.4") observations of CO(7-6), [CI](2-1) and dust continuum of 3 lensed galaxies from the SPT-SMG sample at z\${\textbackslash}sim\$3 with the Atacama Large Millimeter/submillimeter Array. Our sources have high intrinsic star-formation rates ({\textgreater}850 M\$\_{\textbackslash}odot\$ yr\${\textasciicircum}\{-1\}\$) and rather short depletion timescales ({\textless}100 Myr). Based on the \${\textbackslash}rm L\_\{[{\textbackslash}rm CI](2-1)\}/ {\textbackslash}rm L\_\{{\textbackslash}rm CO(7-6)\}\$ and \${\textbackslash}rm L\_\{[{\textbackslash}rm CI](2-1)\}/{\textbackslash}rm L\_\{{\textbackslash}rm IR\}\$ ratios, our sample galaxies exhibit higher radiation field intensity compared to other submillimetre galaxies but have similar gas densities. We perform visibility-based lens modelling on these objects to reconstruct the kinematics in the source plane. We find that the cold gas masses of the sources are compatible with simple dynamical mass estimates using ULIRG-like values of the CO-H\$\_2\$ conversion factor \${\textbackslash}alpha\_\{{\textbackslash}rm CO\}\$ but not Milky Way-like values. We find diverse source kinematics in our sample: SPT0103-45 and SPT2147-50 are likely rotating disks while SPT2357-51 is a probable major merger. The analysis presented in the paper could be extended to a larger sample to determine better statistics of morphologies and interstellar medium properties of high-z dusty star-forming galaxies.},
urldate = {2021-10-14},
author = {Gururajan, G. and Béthermin, M. and Theulé, P. and Spilker, J. S. and Aravena, M. and Archipley, M. A. and Chapman, S. C. and DeBreuck, C. and Gonzalez, A. and Hayward, C. C. and Hezaveh, Y. and Hill, R. and Jarugula, S. and Litke, K. C. and Malkan, M. and Marrone, D. and Narayanan, D. and Phadke, K. A. and Reuter, C. and Vieira, J. and Vizgan, D. and Weiß, A.},
month = sep,
year = {2021},
note = {Publication Title: arXiv e-prints
ADS Bibcode: 2021arXiv210903450G
Type: article},
keywords = {Astrophysics - Astrophysics of Galaxies},
}COALAS: I. ATCA CO(1-0) survey and luminosity function in the Spiderweb protocluster at z=2.16. Jin, S., Dannerbauer, H., Emonts, B., Serra, P., Lagos, C. D. P., Thomson, A. P., Bassini, L., Lehnert, M., Allison, J. R., Champagne, J. B., Indermuhle, B., Norris, R. P., Seymour, N., Shimakawa, R., Casey, C. M., De Breuck, C., Drouart, G., Hatch, N., Kodama, T., Koyama, Y., Macgregor, P., Miley, G., Overzier, R., Perez-Martinez, J. M., Rodriguez-Espinosa, J. M., Rottgering, H., Sanchez Portal, M., & Ziegler, B. arXiv e-prints, 2103:arXiv:2103.08884, March, 2021.
Paper abstract bibtex
Paper abstract bibtex We report a detailed CO(1-0) survey of a galaxy protocluster field at \$z=2.16\$, based on 475 hours of observations with the Australia Telescope Compact Array. We constructed a large mosaic of 13 individual pointings, covering an area of 21 arcmin\${\textasciicircum}2\$ and \${\textbackslash}pm6500\$ km/s range in velocity. We obtain a robust sample of 46 CO(1-0) detections spanning \$z=2.09-2.22\$, constituting the largest sample of molecular gas measurements in protoclusters to date. The CO emitters show an overdensity at \$z=2.12-2.21\$, suggesting a galaxy super-protocluster or a protocluster connected to large-scale filaments with \textasciitilde120 cMpc size. We find that 90% CO emitters have distances \${\textgreater}0'.5-4'\$ to the center galaxy, indicating that small area surveys would miss the majority of gas reservoirs in similar structures. Half of the CO emitters have velocities larger than escape velocities, which appears gravitationally unbound to the cluster core. These unbound sources are barely found within the \$R_\{200\}\$ radius around the center, which is consistent with a picture in which the cluster core is collapsed while outer regions are still in formation. Compared to other protoclusters, this structure contains relatively more CO emitters with relatively narrow line width and high luminosity, indicating galaxy mergers. We use these CO emitters to place the first constraint on the CO luminosity function and molecular gas density in an overdense environment. The amplitude of the CO luminosity function is 1.6\${\textbackslash}pm\$0.5 orders of magnitudes higher than observed for field galaxy samples at \$z{\textbackslash}sim2\$, and one order of magnitude higher than predictions for galaxy protoclusters from semi-analytical SHARK models. We derive a high molecular gas density of \$0.6-1.3{\textbackslash}times10{\textasciicircum}\{9\}\$ \$M_{\textbackslash}odot\$ cMpc\${\textasciicircum}\{-3\}\$ for this structure, consistent with predictions for cold gas density of massive structures from hydro-dynamical DIANOGA simulations.
@article{jin_coalas_2021,
title = {{COALAS}: {I}. {ATCA} {CO}(1-0) survey and luminosity function in the {Spiderweb} protocluster at z=2.16},
volume = {2103},
shorttitle = {{COALAS}},
url = {http://adsabs.harvard.edu/abs/2021arXiv210308884J},
abstract = {We report a detailed CO(1-0) survey of a galaxy protocluster field at
\$z=2.16\$, based on 475 hours of observations with the Australia
Telescope Compact Array. We constructed a large mosaic of 13 individual
pointings, covering an area of 21 arcmin\${\textasciicircum}2\$ and \${\textbackslash}pm6500\$ km/s range in
velocity. We obtain a robust sample of 46 CO(1-0) detections spanning
\$z=2.09-2.22\$, constituting the largest sample of molecular gas
measurements in protoclusters to date. The CO emitters show an
overdensity at \$z=2.12-2.21\$, suggesting a galaxy super-protocluster or
a protocluster connected to large-scale filaments with {\textasciitilde}120 cMpc size.
We find that 90\% CO emitters have distances \${\textgreater}0'.5-4'\$ to the center
galaxy, indicating that small area surveys would miss the majority of
gas reservoirs in similar structures. Half of the CO emitters have
velocities larger than escape velocities, which appears gravitationally
unbound to the cluster core. These unbound sources are barely found
within the \$R\_\{200\}\$ radius around the center, which is consistent with
a picture in which the cluster core is collapsed while outer regions are
still in formation. Compared to other protoclusters, this structure
contains relatively more CO emitters with relatively narrow line width
and high luminosity, indicating galaxy mergers. We use these CO emitters
to place the first constraint on the CO luminosity function and
molecular gas density in an overdense environment. The amplitude of the
CO luminosity function is 1.6\${\textbackslash}pm\$0.5 orders of magnitudes higher than
observed for field galaxy samples at \$z{\textbackslash}sim2\$, and one order of
magnitude higher than predictions for galaxy protoclusters from
semi-analytical SHARK models. We derive a high molecular gas density of
\$0.6-1.3{\textbackslash}times10{\textasciicircum}\{9\}\$ \$M\_{\textbackslash}odot\$ cMpc\${\textasciicircum}\{-3\}\$ for this structure,
consistent with predictions for cold gas density of massive structures
from hydro-dynamical DIANOGA simulations.},
urldate = {2021-03-23},
journal = {arXiv e-prints},
author = {Jin, S. and Dannerbauer, H. and Emonts, B. and Serra, P. and Lagos, C. D. P. and Thomson, A. P. and Bassini, L. and Lehnert, M. and Allison, J. R. and Champagne, J. B. and Indermuhle, B. and Norris, R. P. and Seymour, N. and Shimakawa, R. and Casey, C. M. and De Breuck, C. and Drouart, G. and Hatch, N. and Kodama, T. and Koyama, Y. and Macgregor, P. and Miley, G. and Overzier, R. and Perez-Martinez, J. M. and Rodriguez-Espinosa, J. M. and Rottgering, H. and Sanchez Portal, M. and Ziegler, B.},
month = mar,
year = {2021},
keywords = {Astrophysics - Astrophysics of Galaxies, Astrophysics - Cosmology and Nongalactic Astrophysics},
pages = {arXiv:2103.08884},
}Relative distribution of dark matter, gas and stars around cosmic filaments in the IllustrisTNG simulation. Galárraga-Espinosa, D., Langer, M., & Aghanim, N. arXiv:2109.06198 [astro-ph], September, 2021. arXiv: 2109.06198
Paper abstract bibtex
Paper abstract bibtex We present a comprehensive study of the distribution of matter around different populations of filaments, using the IllustrisTNG simulation at z=0. We compute the dark matter (DM), gas, and stellar radial density profiles of filaments, and we characterise the distribution of the baryon fraction in these structures. We find that baryons exactly follow the underlying DM distribution only down to r\textasciitilde7 Mpc to the filament spines. At shorter distances (r\textless7 Mpc) the baryon fraction profile of filaments departs from the cosmic value Omega_b/Omega_m. While in the r\textasciitilde0.7 - 7 Mpc radial domain this departure is due to the radial accretion of WHIM gas towards the filament cores (creating an excess of baryons with respect to the cosmic fraction), the cores of filaments (r\textless0.7 Mpc) show instead a clear baryon depletion, quantified by a depletion factor of Y_b = 0.63-0.68. The analysis of the efficiency of AGN feedback events in filaments reveals that they are potentially powerful enough to eject gas outside of the gravitational potential wells of filaments. We show that the large-scale environment (i.e. denser vs less-dense, hotter vs colder regions) has a non-negligible effect on the absolute values of the DM, gas, and stellar densities around filaments. Nevertheless, the relative distribution of baryons with respect to the underlying DM density field is found to be independent from the filament population. Finally, we provide scaling relations between gas density, temperature, and pressure for the different populations of cosmic filaments. We compare these relations to those pertaining to clusters of galaxies, and find that these cosmic structures occupy separate regions of the density-temperature and density-pressure planes.
@article{galarraga-espinosa_relative_2021,
title = {Relative distribution of dark matter, gas and stars around cosmic filaments in the {IllustrisTNG} simulation},
url = {http://arxiv.org/abs/2109.06198},
abstract = {We present a comprehensive study of the distribution of matter around different populations of filaments, using the IllustrisTNG simulation at z=0. We compute the dark matter (DM), gas, and stellar radial density profiles of filaments, and we characterise the distribution of the baryon fraction in these structures. We find that baryons exactly follow the underlying DM distribution only down to r{\textasciitilde}7 Mpc to the filament spines. At shorter distances (r{\textless}7 Mpc) the baryon fraction profile of filaments departs from the cosmic value Omega\_b/Omega\_m. While in the r{\textasciitilde}0.7 - 7 Mpc radial domain this departure is due to the radial accretion of WHIM gas towards the filament cores (creating an excess of baryons with respect to the cosmic fraction), the cores of filaments (r{\textless}0.7 Mpc) show instead a clear baryon depletion, quantified by a depletion factor of Y\_b = 0.63-0.68. The analysis of the efficiency of AGN feedback events in filaments reveals that they are potentially powerful enough to eject gas outside of the gravitational potential wells of filaments. We show that the large-scale environment (i.e. denser vs less-dense, hotter vs colder regions) has a non-negligible effect on the absolute values of the DM, gas, and stellar densities around filaments. Nevertheless, the relative distribution of baryons with respect to the underlying DM density field is found to be independent from the filament population. Finally, we provide scaling relations between gas density, temperature, and pressure for the different populations of cosmic filaments. We compare these relations to those pertaining to clusters of galaxies, and find that these cosmic structures occupy separate regions of the density-temperature and density-pressure planes.},
urldate = {2021-10-25},
journal = {arXiv:2109.06198 [astro-ph]},
author = {Galárraga-Espinosa, Daniela and Langer, Mathieu and Aghanim, Nabila},
month = sep,
year = {2021},
note = {arXiv: 2109.06198},
keywords = {Astrophysics - Astrophysics of Galaxies, Astrophysics - Cosmology and Nongalactic Astrophysics},
}Evolution of the galaxy stellar mass function: evidence for an increasing \${M}{\textasciicircum}*\$ from \$z=2\$ to the present day. Adams, N. J., Bowler, R. A. A., Jarvis, M. J., Haußler, B., & Lagos, C. D. P. arXiv e-prints, 2101:arXiv:2101.07182, January, 2021.
Paper abstract bibtex
Paper abstract bibtex Utilising optical and near-infrared broadband photometry covering \${\textgreater} 5{\textbackslash},\{{\textbackslash}rm deg\}{\textasciicircum}2\$ in two of the most well-studied extragalactic legacy fields (COSMOS and XMM-LSS), we measure the galaxy stellar mass function (GSMF) between \$0.1 {\textless} z {\textless} 2.0\$. We explore in detail the effect of two source extraction methods (SExtractor and ProFound) in addition to the inclusion/exclusion of Spitzer IRAC 3.6 and 4.5\${\textbackslash}mu\$m photometry when measuring the GSMF. We find that including IRAC data reduces the number of massive (\${\textbackslash}log_\{10\}(M/M_{\textbackslash}odot) {\textgreater} 11.25\$) galaxies found due to improved photometric redshift accuracy, but has little effect on the more numerous lower-mass galaxies. We fit the resultant GSMFs with double Schechter functions down to \${\textbackslash}log_\{10\}(M/M_{\textbackslash}odot)\$ = 7.75 (9.75) at z = 0.1 (2.0) and find that the choice of source extraction software has no significant effect on the derived best-fit parameters. However, the choice of methodology used to correct for the Eddington bias has a larger impact on the high-mass end of the GSMF, which can partly explain the spread in derived \$M{\textasciicircum}*\$ values from previous studies. Using an empirical correction to model the intrinsic GSMF, we find evidence for an evolving characteristic stellar mass with \${\textbackslash}delta {\textbackslash}log_\{10\}(M{\textasciicircum}*/M_{\textbackslash}odot)/{\textbackslash}delta z\$ = \$-0.16{\textbackslash}pm0.05 {\textbackslash}, (-0.11{\textbackslash}pm0.05)\$, when using SExtractor (ProFound). We argue that with widely quenched star formation rates in massive galaxies at low redshift (\$z{\textless}0.5\$), additional growth via mergers is required in order to sustain such an evolution to a higher characteristic mass.
@article{adams_evolution_2021,
title = {Evolution of the galaxy stellar mass function: evidence for an increasing \${M}{\textasciicircum}*\$ from \$z=2\$ to the present day},
volume = {2101},
shorttitle = {Evolution of the galaxy stellar mass function},
url = {http://adsabs.harvard.edu/abs/2021arXiv210107182A},
abstract = {Utilising optical and near-infrared broadband photometry covering \${\textgreater}
5{\textbackslash},\{{\textbackslash}rm deg\}{\textasciicircum}2\$ in two of the most well-studied extragalactic legacy
fields (COSMOS and XMM-LSS), we measure the galaxy stellar mass function
(GSMF) between \$0.1 {\textless} z {\textless} 2.0\$. We explore in detail the effect of
two source extraction methods (SExtractor and ProFound) in addition to
the inclusion/exclusion of Spitzer IRAC 3.6 and 4.5\${\textbackslash}mu\$m photometry
when measuring the GSMF. We find that including IRAC data reduces the
number of massive (\${\textbackslash}log\_\{10\}(M/M\_{\textbackslash}odot) {\textgreater} 11.25\$) galaxies found due
to improved photometric redshift accuracy, but has little effect on the
more numerous lower-mass galaxies. We fit the resultant GSMFs with
double Schechter functions down to \${\textbackslash}log\_\{10\}(M/M\_{\textbackslash}odot)\$ = 7.75 (9.75)
at z = 0.1 (2.0) and find that the choice of source extraction software
has no significant effect on the derived best-fit parameters. However,
the choice of methodology used to correct for the Eddington bias has a
larger impact on the high-mass end of the GSMF, which can partly explain
the spread in derived \$M{\textasciicircum}*\$ values from previous studies. Using an
empirical correction to model the intrinsic GSMF, we find evidence for
an evolving characteristic stellar mass with \${\textbackslash}delta
{\textbackslash}log\_\{10\}(M{\textasciicircum}*/M\_{\textbackslash}odot)/{\textbackslash}delta z\$ = \$-0.16{\textbackslash}pm0.05 {\textbackslash}, (-0.11{\textbackslash}pm0.05)\$,
when using SExtractor (ProFound). We argue that with widely quenched
star formation rates in massive galaxies at low redshift (\$z{\textless}0.5\$),
additional growth via mergers is required in order to sustain such an
evolution to a higher characteristic mass.},
urldate = {2021-02-04},
journal = {arXiv e-prints},
author = {Adams, N. J. and Bowler, R. A. A. and Jarvis, M. J. and Haußler, B. and Lagos, C. D. P.},
month = jan,
year = {2021},
keywords = {Astrophysics - Astrophysics of Galaxies},
pages = {arXiv:2101.07182},
}Measuring the HI content of individual galaxies out to the epoch of reionization with [CII]. Heintz, K. E., Watson, D., Oesch, P., Narayanan, D., & Madden, S. C. Technical Report August, 2021. Publication Title: arXiv e-prints ADS Bibcode: 2021arXiv210813442H Type: article
Paper abstract bibtex
Paper abstract bibtex The HI gas content is a key ingredient in galaxy evolution, the study of which has been limited to moderate cosmological distances for individual galaxies due to the weakness of the hyperfine HI 21-cm transition. Here we present a new approach that allows us to infer the HI gas mass \$M_\{{\textbackslash}rm HI\}\$ of individual galaxies up to \$z{\textbackslash}approx 6\$, based on a direct measurement of the [CII]-to-HI conversion factor in star-forming galaxies at \$zrsim 2\$ using \${\textbackslash}gamma\$-ray burst afterglows. By compiling recent [CII]-158 \${\textbackslash}mu\$m emission line measurements we quantify the evolution of the HI content in galaxies through cosmic time. We find that the HI mass starts to exceed the stellar mass \$M_{\textbackslash}star\$ at \$zrsim 1\$, and increases as a function of redshift. The HI fraction of the total baryonic mass increases from around \$20{\textbackslash}%\$ at \$z = 0\$ to about \$60{\textbackslash}%\$ at \$z{\textbackslash}sim 6\$. We further uncover a universal relation between the HI gas fraction \$M_\{{\textbackslash}rm HI\}/M_{\textbackslash}star\$ and the gas-phase metallicity, which seems to hold from \$z{\textbackslash}approx 6\$ to \$z=0\$. The majority of galaxies at \$z{\textgreater}2\$ are observed to have HI depletion times, \$t_\{{\textbackslash}rm dep,HI\} = M_\{{\textbackslash}rm HI\}/\{{\textbackslash}rm SFR\}\$, less than \${\textbackslash}approx 2\$ Gyr, substantially shorter than for \$z{\textbackslash}sim 0\$ galaxies. Finally, we use the [CII]-to-HI conversion factor to determine the cosmic mass density of HI in galaxies, \${\textbackslash}rho_\{{\textbackslash}rm HI\}\$, at three distinct epochs: \$z{\textbackslash}approx 0\$, \$z{\textbackslash}approx 2\$, and \$z{\textbackslash}sim 4-6\$. These measurements are consistent with previous estimates based on 21-cm HI observations in the local Universe and with damped Lyman-\${\textbackslash}alpha\$ absorbers (DLAs) at \$zrsim 2\$, suggesting an overall decrease by a factor of \${\textbackslash}approx 5\$ in \${\textbackslash}rho_\{{\textbackslash}rm HI\}(z)\$ from the end of the reionization epoch to the present.
@techreport{2021arXiv210813442H,
title = {Measuring the {HI} content of individual galaxies out to the epoch of reionization with [{CII}]},
url = {https://ui.adsabs.harvard.edu/abs/2021arXiv210813442H},
abstract = {The HI gas content is a key ingredient in galaxy evolution, the study of which has been limited to moderate cosmological distances for individual galaxies due to the weakness of the hyperfine HI 21-cm transition. Here we present a new approach that allows us to infer the HI gas mass \$M\_\{{\textbackslash}rm HI\}\$ of individual galaxies up to \$z{\textbackslash}approx 6\$, based on a direct measurement of the [CII]-to-HI conversion factor in star-forming galaxies at \$zrsim 2\$ using \${\textbackslash}gamma\$-ray burst afterglows. By compiling recent [CII]-158 \${\textbackslash}mu\$m emission line measurements we quantify the evolution of the HI content in galaxies through cosmic time. We find that the HI mass starts to exceed the stellar mass \$M\_{\textbackslash}star\$ at \$zrsim 1\$, and increases as a function of redshift. The HI fraction of the total baryonic mass increases from around \$20{\textbackslash}\%\$ at \$z = 0\$ to about \$60{\textbackslash}\%\$ at \$z{\textbackslash}sim 6\$. We further uncover a universal relation between the HI gas fraction \$M\_\{{\textbackslash}rm HI\}/M\_{\textbackslash}star\$ and the gas-phase metallicity, which seems to hold from \$z{\textbackslash}approx 6\$ to \$z=0\$. The majority of galaxies at \$z{\textgreater}2\$ are observed to have HI depletion times, \$t\_\{{\textbackslash}rm dep,HI\} = M\_\{{\textbackslash}rm HI\}/\{{\textbackslash}rm SFR\}\$, less than \${\textbackslash}approx 2\$ Gyr, substantially shorter than for \$z{\textbackslash}sim 0\$ galaxies. Finally, we use the [CII]-to-HI conversion factor to determine the cosmic mass density of HI in galaxies, \${\textbackslash}rho\_\{{\textbackslash}rm HI\}\$, at three distinct epochs: \$z{\textbackslash}approx 0\$, \$z{\textbackslash}approx 2\$, and \$z{\textbackslash}sim 4-6\$. These measurements are consistent with previous estimates based on 21-cm HI observations in the local Universe and with damped Lyman-\${\textbackslash}alpha\$ absorbers (DLAs) at \$zrsim 2\$, suggesting an overall decrease by a factor of \${\textbackslash}approx 5\$ in \${\textbackslash}rho\_\{{\textbackslash}rm HI\}(z)\$ from the end of the reionization epoch to the present.},
urldate = {2021-09-07},
author = {Heintz, Kasper E. and Watson, Darach and Oesch, Pascal and Narayanan, Desika and Madden, Suzanne C.},
month = aug,
year = {2021},
note = {Publication Title: arXiv e-prints
ADS Bibcode: 2021arXiv210813442H
Type: article},
keywords = {Astrophysics - Astrophysics of Galaxies, Astrophysics - High Energy Astrophysical Phenomena},
}The morphology of star-forming gas and its alignment with galaxies and dark matter haloes in the EAGLE simulations. Hill, A. D., Crain, R. A., Kwan, J., & McCarthy, I. G. arXiv e-prints, 2102:arXiv:2102.13603, February, 2021.
Paper abstract bibtex
Paper abstract bibtex We present measurements of the morphology of star-forming gas in galaxies from the EAGLE simulations, and its alignment relative to stars and dark matter (DM). Imaging of such gas in the radio continuum enables weak lensing experiments that complement traditional optical approaches. Star-forming gas is typically more flattened than its associated stars and DM, particularly for present-day subhaloes of total mass \${\textbackslash}sim\$\$10{\textasciicircum}\{p̌hantom{\}} 12-12.5p̌hantom{\{}\} {\textbackslash}mathrm\{M_\{ {\textbackslash}odot\}\}\$, which preferentially host star-forming galaxies with rotationally-supported stellar discs. Such systems have oblate, spheroidal star-forming gas distributions, but in both less- and more-massive subhaloes the distributions tend to be prolate, and its morphology correlates positively and significantly with that of its host galaxy's stars, both in terms of sphericity and triaxiality. The minor axis of star-forming gas most commonly aligns with the minor axis of its host subhalo's DM, but often aligns more closely with one of the other two principal axes of the DM distribution in prolate subhaloes. Star-forming gas aligns with DM less strongly than is the case for stars, but its morphological minor axis aligns closely with its kinematic axis, affording a route to observational identification of the unsheared morphological axis. The projected ellipticities of star-forming gas in EAGLE are consistent with shapes inferred from high-fidelity radio continuum images, and they exhibit greater shape noise than is the case for images of the stars, owing to the greater characteristic flattening of star-forming gas with respect to stars.
@article{hill_morphology_2021,
title = {The morphology of star-forming gas and its alignment with galaxies and dark matter haloes in the {EAGLE} simulations},
volume = {2102},
url = {http://adsabs.harvard.edu/abs/2021arXiv210213603H},
abstract = {We present measurements of the morphology of star-forming gas in
galaxies from the EAGLE simulations, and its alignment relative to stars
and dark matter (DM). Imaging of such gas in the radio continuum enables
weak lensing experiments that complement traditional optical approaches.
Star-forming gas is typically more flattened than its associated stars
and DM, particularly for present-day subhaloes of total mass \${\textbackslash}sim\$\$10{\textasciicircum}\{\vphantom{\}}
12-12.5\vphantom{\{}\} {\textbackslash}mathrm\{M\_\{ {\textbackslash}odot\}\}\$, which preferentially host star-forming
galaxies with rotationally-supported stellar discs. Such systems have
oblate, spheroidal star-forming gas distributions, but in both less- and
more-massive subhaloes the distributions tend to be prolate, and its
morphology correlates positively and significantly with that of its host
galaxy's stars, both in terms of sphericity and triaxiality. The minor
axis of star-forming gas most commonly aligns with the minor axis of its
host subhalo's DM, but often aligns more closely with one of the other
two principal axes of the DM distribution in prolate subhaloes.
Star-forming gas aligns with DM less strongly than is the case for
stars, but its morphological minor axis aligns closely with its
kinematic axis, affording a route to observational identification of the
unsheared morphological axis. The projected ellipticities of
star-forming gas in EAGLE are consistent with shapes inferred from
high-fidelity radio continuum images, and they exhibit greater shape
noise than is the case for images of the stars, owing to the greater
characteristic flattening of star-forming gas with respect to stars.},
urldate = {2021-03-04},
journal = {arXiv e-prints},
author = {Hill, Alexander D. and Crain, Robert A. and Kwan, Juliana and McCarthy, Ian G.},
month = feb,
year = {2021},
keywords = {Astrophysics - Astrophysics of Galaxies, Astrophysics - Cosmology and Nongalactic Astrophysics},
pages = {arXiv:2102.13603},
}2020 (16)
Evolution of Disc Thickness in High-Redshift Galaxies. Meng, X. & Gnedin, O. Y. arXiv e-prints, 2006:arXiv:2006.10642, June, 2020.
Paper abstract bibtex
Paper abstract bibtex We study the growth of stellar discs of Milky Way-sized galaxies using a suite of cosmological simulations. We calculate the half-mass axis lengths and axis ratios of stellar populations split by age in isolated galaxies with stellar mass \$M_* = 10{\textasciicircum}7 - 10{\textasciicircum}\{10\} M_\{{\textbackslash}odot\}\$ at redshifts \$z\$ \textgreater 1.5. We find that in our simulations stars always form in relatively thin discs, and at ages below 100 Myr are contained within half-mass height \$z_\{1/2\}\$ \textasciitilde 0.1 kpc and short-to-long axis ratio \$z_\{1/2\}/x_\{1/2\}\$ \textasciitilde 0.15. The disc thickness increases with the age of stellar population, reaching median \$z_\{1/2\}\$ \textasciitilde 0.8 kpc and \$z_\{1/2\}/x_\{1/2\}\$ \textasciitilde 0.6 for stars older than 500 Myr. We trace the same group of stars over the simulation snapshots and show explicitly that their intrinsic shape grows more spheroidal over time. The observed increase in disc thickness is due to the gradual vertical expansion of the originally thin stellar population, combined with the rapidly changing orientation of the galactic plane which mixes the configuration of young stars. The frequently mentioned "upside-down" formation scenario of galactic discs, which posits that young stars form in already thick discs at high redshift, is describing only the final product of this quick disc inflation while missing the actual formation of stars within a fairly thin plane. The location of very young stars in thin discs is due to the correspondingly flat configuration of dense molecular gas that participates in star formation.
@article{meng_evolution_2020,
title = {Evolution of {Disc} {Thickness} in {High}-{Redshift} {Galaxies}},
volume = {2006},
url = {http://adsabs.harvard.edu/abs/2020arXiv200610642M},
abstract = {We study the growth of stellar discs of Milky Way-sized galaxies using a suite of cosmological simulations. We calculate the half-mass axis lengths and axis ratios of stellar populations split by age in isolated galaxies with stellar mass \$M\_* = 10{\textasciicircum}7 - 10{\textasciicircum}\{10\} M\_\{{\textbackslash}odot\}\$ at redshifts \$z\$ {\textgreater} 1.5. We find that in our simulations stars always form in
relatively thin discs, and at ages below 100 Myr are contained within half-mass height \$z\_\{1/2\}\$ {\textasciitilde} 0.1 kpc and short-to-long axis ratio \$z\_\{1/2\}/x\_\{1/2\}\$ {\textasciitilde} 0.15. The disc thickness increases with the age of stellar population, reaching median \$z\_\{1/2\}\$ {\textasciitilde} 0.8 kpc and
\$z\_\{1/2\}/x\_\{1/2\}\$ {\textasciitilde} 0.6 for stars older than 500 Myr. We trace the same group of stars over the simulation snapshots and show explicitly that their intrinsic shape grows more spheroidal over time. The observed increase in disc thickness is due to the gradual vertical expansion of the originally thin stellar population, combined with the rapidly changing orientation of the galactic plane which mixes the configuration of young stars. The frequently mentioned "upside-down" formation scenario of galactic discs, which posits that young stars form in already thick discs at high redshift, is describing only the final product of this quick disc inflation while missing the actual formation of stars within a fairly thin plane. The location of very young stars in thin discs is due to the correspondingly flat configuration of dense molecular gas that participates in star formation.},
urldate = {2020-06-22},
journal = {arXiv e-prints},
author = {Meng, Xi and Gnedin, Oleg Y.},
month = jun,
year = {2020},
keywords = {Astrophysics - Astrophysics of Galaxies},
pages = {arXiv:2006.10642},
}Radial Star Formation Histories in 32 Nearby Galaxies. Dale, D. A., Anderson, K. R., Bran, L. M., Cox, I. S., Drake, C. L., Lee, N. J., Pilawa, J. D., Alexander Slane, F., Soto, S., Jensen, E. I., Sutter, J. S., Turner, J. A., & Kobulnicky, H. A. \aj, 159(5):195, May, 2020.
doi bibtex
doi bibtex
@ARTICLE{2020AJ....159..195D,
author = {{Dale}, Daniel A. and {Anderson}, Kristin R. and {Bran}, Louis M. and {Cox}, Isaiah S. and {Drake}, Carolyn L. and {Lee}, Nathan J. and {Pilawa}, Jacob D. and {Alexander Slane}, F. and {Soto}, Susana and {Jensen}, Emily I. and {Sutter}, Jessica S. and {Turner}, Jordan A. and {Kobulnicky}, Henry A.},
title = "{Radial Star Formation Histories in 32 Nearby Galaxies}",
journal = {\aj},
keywords = {576, 594, 598, Astrophysics - Astrophysics of Galaxies},
year = 2020,
month = may,
volume = {159},
number = {5},
eid = {195},
pages = {195},
doi = {10.3847/1538-3881/ab7eb2},
archivePrefix = {arXiv},
eprint = {2003.10260},
primaryClass = {astro-ph.GA},
adsurl = {https://ui.adsabs.harvard.edu/abs/2020AJ....159..195D},
adsnote = {Provided by the SAO/NASA Astrophysics Data System}
}The ALMA Spectroscopic Survey Large Program: The Infrared Excess of z=1.5-10 UV-selected Galaxies and the Implied High-Redshift Star Formation History. Bouwens, R., Gonzalez-Lopez, J., Aravena, M., Decarli, R., Novak, M., Stefanon, M., Walter, F., Boogaard, L., Carilli, C., Dudzeviciute, U., Smail, I., Daddi, E., da Cunha, E., Ivison, R., Nanayakkara, T., Cortes, P., Cox, P., Inami, H., Oesch, P., Popping, G., Riechers, D., van der Werf, P., Weiss, A., Fudamoto, Y., & Wagg, J. arXiv e-prints, 2009:arXiv:2009.10727, September, 2020.
Paper abstract bibtex
Paper abstract bibtex We make use of sensitive (9.3 microJy/beam RMS) 1.2mm-continuum observations from the ASPECS ALMA large program of the Hubble Ultra Deep Field (HUDF) to probe dust-enshrouded star formation from 1362 Lyman-break galaxies spanning the redshift range z=1.5-10 (to \textasciitilde7-28 Msolar/yr at 4 sigma over the entire range). We find that the fraction of ALMA-detected galaxies in our z=1.5-10 samples increases steeply with stellar mass, with the detection fraction rising from 0% at 10\textasciicircum9 Msolar to 85(-18)(+9)% at \textgreater10\textasciicircum\10\ Msolar. Moreover, stacking all 1253 low-mass (\textless10\textasciicircum\9.25\ Msolar) galaxies over the ASPECS footprint, we find a mean continuum flux of -0.1+/-0.4 microJy/beam, implying a hard upper limit on the obscured SFR of \textless0.6 Msolar/yr (4 sigma) in a typical low-mass galaxy. The correlation between the infrared excess IRX of UV-selected galaxies (L(IR)/L(UV)) and the UV-continuum slope is also seen in our ASPECS data and shows consistency with a Calzetti-like relation at \textgreater10\textasciicircum\9.5\ M_\solar\ and a SMC-like relation at lower masses. Using stellar-mass and beta measurements for z\textasciitilde2 galaxies over CANDELS, we derive a new empirical relation between beta and stellar mass and then use this correlation to show that our IRX-beta and IRX-stellar mass relations are consistent with each other. We then use these constraints to express the infrared excess as a bivariate function of beta and stellar mass. Finally, we present updated estimates of star-formation rate density determinations at z\textgreater3, leveraging current improvements in the measured infrared excess and recent probes of ultra-luminous far-IR galaxies at z\textgreater2.
@article{bouwens_alma_2020,
title = {The {ALMA} {Spectroscopic} {Survey} {Large} {Program}: {The} {Infrared} {Excess} of z=1.5-10 {UV}-selected {Galaxies} and the {Implied} {High}-{Redshift} {Star} {Formation} {History}},
volume = {2009},
shorttitle = {The {ALMA} {Spectroscopic} {Survey} {Large} {Program}},
url = {http://adsabs.harvard.edu/abs/2020arXiv200910727B},
abstract = {We make use of sensitive (9.3 microJy/beam RMS) 1.2mm-continuum
observations from the ASPECS ALMA large program of the Hubble Ultra Deep
Field (HUDF) to probe dust-enshrouded star formation from 1362
Lyman-break galaxies spanning the redshift range z=1.5-10 (to {\textasciitilde}7-28
Msolar/yr at 4 sigma over the entire range). We find that the fraction
of ALMA-detected galaxies in our z=1.5-10 samples increases steeply with
stellar mass, with the detection fraction rising from 0\% at 10{\textasciicircum}9 Msolar
to 85(-18)(+9)\% at {\textgreater}10{\textasciicircum}\{10\} Msolar. Moreover, stacking all 1253
low-mass ({\textless}10{\textasciicircum}\{9.25\} Msolar) galaxies over the ASPECS footprint, we
find a mean continuum flux of -0.1+/-0.4 microJy/beam, implying a hard
upper limit on the obscured SFR of {\textless}0.6 Msolar/yr (4 sigma) in a
typical low-mass galaxy. The correlation between the infrared excess IRX
of UV-selected galaxies (L(IR)/L(UV)) and the UV-continuum slope is also
seen in our ASPECS data and shows consistency with a Calzetti-like
relation at {\textgreater}10{\textasciicircum}\{9.5\} M\_\{solar\} and a SMC-like relation at lower
masses. Using stellar-mass and beta measurements for z{\textasciitilde}2 galaxies over
CANDELS, we derive a new empirical relation between beta and stellar
mass and then use this correlation to show that our IRX-beta and
IRX-stellar mass relations are consistent with each other. We then use
these constraints to express the infrared excess as a bivariate function
of beta and stellar mass. Finally, we present updated estimates of
star-formation rate density determinations at z{\textgreater}3, leveraging current
improvements in the measured infrared excess and recent probes of
ultra-luminous far-IR galaxies at z{\textgreater}2.},
urldate = {2020-10-22},
journal = {arXiv e-prints},
author = {Bouwens, Rychard and Gonzalez-Lopez, Jorge and Aravena, Manuel and Decarli, Roberto and Novak, Mladen and Stefanon, Mauro and Walter, Fabian and Boogaard, Leindert and Carilli, Chris and Dudzeviciute, Ugne and Smail, Ian and Daddi, Emanuele and da Cunha, Elisabete and Ivison, Rob and Nanayakkara, Themiya and Cortes, Paulo and Cox, Pierre and Inami, Hanae and Oesch, Pascal and Popping, Gergo and Riechers, Dominik and van der Werf, Paul and Weiss, Axel and Fudamoto, Yoshi and Wagg, Jeff},
month = sep,
year = {2020},
keywords = {Astrophysics - Astrophysics of Galaxies},
pages = {arXiv:2009.10727},
}The kinematics of massive quiescent galaxies at \$1.4 {\textless} z {\textless} 2.1\$: dark matter fractions, IMF variation, and the relation to local early-type galaxies. Mendel, J. T., Beifiori, A., Saglia, R., Bender, R., Brammer, G., Chan, J., Forster Schreiber, N., Fossati, M., Galametz, A., Momcheva, I., Nelson, E., Wilman, D., & Wuyts, S. arXiv e-prints, 2006:arXiv:2006.13949, June, 2020.
Paper abstract bibtex
Paper abstract bibtex We study the dynamical properties of massive quiescent galaxies at \$1.4 {\textless} z {\textless} 2.1\$ using deep Hubble Space Telescope WFC3/F160W imaging and a combination of literature stellar velocity dispersion measurements and new near-infrared spectra obtained using KMOS on the ESO VLT. We use these data to show that the typical dynamical-to-stellar mass ratio has increased by \${\textbackslash}sim\$0.2 dex from \$z = 2\$ to the present day, and investigate this evolution in the context of possible changes in the stellar initial mass function (IMF) and/or fraction of dark matter contained within the galaxy effective radius, \$f_{\textbackslash}mathrm\{DM\}\$. Comparing our high-redshift sample to their likely descendants at low-redshift, we find that \$f_{\textbackslash}mathrm\{DM\}\$ has increased by a factor of more than 4 since \$z {\textbackslash}approx 1.8\$, from \$f_{\textbackslash}mathrm\{DM\}\$ = \$6.6{\textbackslash}pm1.0\$% to \${\textbackslash}sim\$24%. The observed increase appears robust to changes in the methods used to estimate dynamical masses or match progenitors and descendants. We quantify possible variation of the stellar IMF through the offset parameter \${\textbackslash}alpha\$, defined as the ratio of dynamical mass in stars to the stellar mass estimated using a Chabrier IMF. We demonstrate that the correlation between stellar velocity dispersion and \${\textbackslash}alpha\$ reported among quiescent galaxies at low-redshift is already in place at \$z = 2\$, and argue that subsequent evolution through (mostly minor) merging should act to preserve this relation while contributing significantly to galaxies overall growth in size and stellar mass.
@article{mendel_kinematics_2020,
title = {The kinematics of massive quiescent galaxies at \$1.4 {\textless} z {\textless} 2.1\$: dark matter fractions, {IMF} variation, and the relation to local early-type galaxies},
volume = {2006},
shorttitle = {The kinematics of massive quiescent galaxies at \$1.4 {\textless} z {\textless} 2.1\$},
url = {http://adsabs.harvard.edu/abs/2020arXiv200613949M},
abstract = {We study the dynamical properties of massive quiescent galaxies at \$1.4
{\textless} z {\textless} 2.1\$ using deep Hubble Space Telescope WFC3/F160W imaging
and a combination of literature stellar velocity dispersion measurements
and new near-infrared spectra obtained using KMOS on the ESO VLT. We use
these data to show that the typical dynamical-to-stellar mass ratio has
increased by \${\textbackslash}sim\$0.2 dex from \$z = 2\$ to the present day, and
investigate this evolution in the context of possible changes in the
stellar initial mass function (IMF) and/or fraction of dark matter
contained within the galaxy effective radius, \$f\_{\textbackslash}mathrm\{DM\}\$. Comparing
our high-redshift sample to their likely descendants at low-redshift, we
find that \$f\_{\textbackslash}mathrm\{DM\}\$ has increased by a factor of more than 4 since
\$z {\textbackslash}approx 1.8\$, from \$f\_{\textbackslash}mathrm\{DM\}\$ = \$6.6{\textbackslash}pm1.0\$\% to \${\textbackslash}sim\$24\%. The
observed increase appears robust to changes in the methods used to
estimate dynamical masses or match progenitors and descendants. We
quantify possible variation of the stellar IMF through the offset
parameter \${\textbackslash}alpha\$, defined as the ratio of dynamical mass in stars to
the stellar mass estimated using a Chabrier IMF. We demonstrate that the
correlation between stellar velocity dispersion and \${\textbackslash}alpha\$ reported
among quiescent galaxies at low-redshift is already in place at \$z = 2\$,
and argue that subsequent evolution through (mostly minor) merging
should act to preserve this relation while contributing significantly to
galaxies overall growth in size and stellar mass.},
urldate = {2020-06-29},
journal = {arXiv e-prints},
author = {Mendel, J. Trevor and Beifiori, Alessandra and Saglia, Roberto and Bender, Ralf and Brammer, Gabe and Chan, Jeffrey and Forster Schreiber, Natascha and Fossati, Matteo and Galametz, Audrey and Momcheva, Iva and Nelson, Erica and Wilman, Dave and Wuyts, Stijn},
month = jun,
year = {2020},
keywords = {Astrophysics - Astrophysics of Galaxies},
pages = {arXiv:2006.13949},
}Stellar Masses of Giant Clumps in CANDELS and Simulated Galaxies Using Machine Learning. Huertas-Company, M., Guo, Y., Ginzburg, O., Lee, C. T., Mandelker, N., Metter, M., Primack, J. R., Dekel, A., Ceverino, D., Faber, S. M., Koo, D. C., Koekemoer, A., Snyder, G., Giavalisco, M., & Zhang, H. arXiv e-prints, 2006:arXiv:2006.14636, June, 2020.
Paper abstract bibtex
Paper abstract bibtex A significant fraction of high redshift star-forming disc galaxies are known to host giant clumps, whose formation, nature and role in galaxy evolution are yet to be understood. In this work we first present a new automated method based on deep neural networks to detect clumps in galaxy images and show that it is more sensitive and faster than previous proposed methods. We then use this method to systematically detect clumps in the rest-frame optical and UV images of a complete sample of \${\textbackslash}sim1500\$ star forming galaxies at \$110{\textasciicircum}\{7\}M_{\textbackslash}odot\$) off-centered clump but only \${\textbackslash}sim2-5{\textbackslash}%\$ of the total galaxy stellar mass is in those clumps. We also show indications that the contribution of clumps to the stellar mass is more important in extended and low mass galaxies. The simulations explored in this work overall reproduce the shape of the observed clump stellar mass function when confronted under the same conditions although tend to lie in the lower limit of the confidence intervals of the observations. This agreement suggests that most of the observed clumps are formed in-situ through violent disk instabilities.
@article{huertas-company_stellar_2020,
title = {Stellar {Masses} of {Giant} {Clumps} in {CANDELS} and {Simulated} {Galaxies} {Using} {Machine} {Learning}},
volume = {2006},
url = {http://adsabs.harvard.edu/abs/2020arXiv200614636H},
abstract = {A significant fraction of high redshift star-forming disc galaxies are
known to host giant clumps, whose formation, nature and role in galaxy
evolution are yet to be understood. In this work we first present a new
automated method based on deep neural networks to detect clumps in
galaxy images and show that it is more sensitive and faster than
previous proposed methods. We then use this method to systematically
detect clumps in the rest-frame optical and UV images of a complete
sample of \${\textbackslash}sim1500\$ star forming galaxies at \$110{\textasciicircum}\{7\}M\_{\textbackslash}odot\$) off-centered clump but only \${\textbackslash}sim2-5{\textbackslash}\%\$ of the
total galaxy stellar mass is in those clumps. We also show indications
that the contribution of clumps to the stellar mass is more important in
extended and low mass galaxies. The simulations explored in this work
overall reproduce the shape of the observed clump stellar mass function
when confronted under the same conditions although tend to lie in the
lower limit of the confidence intervals of the observations. This
agreement suggests that most of the observed clumps are formed in-situ
through violent disk instabilities.},
urldate = {2020-06-29},
journal = {arXiv e-prints},
author = {Huertas-Company, M. and Guo, Y. and Ginzburg, O. and Lee, C. T. and Mandelker, N. and Metter, M. and Primack, J. R. and Dekel, A. and Ceverino, D. and Faber, S. M. and Koo, D. C. and Koekemoer, A. and Snyder, G. and Giavalisco, M. and Zhang, H.},
month = jun,
year = {2020},
keywords = {Astrophysics - Astrophysics of Galaxies, Astrophysics - Cosmology and Nongalactic Astrophysics},
pages = {arXiv:2006.14636},
}MEGA: Merger graphs of structure formation. Roper, W. J., Thomas, P. A., & Srisawat, C. arXiv:2003.01187 [astro-ph], March, 2020. arXiv: 2003.01187
Paper abstract bibtex
Paper abstract bibtex When following the growth of structure in the Universe, we propose replacing merger trees with merger graphs, in which haloes can both merge and split into separate pieces. We show that this leads to smoother mass growth and eliminates catastrophic failures in which massive haloes have no progenitors or descendants. For those who prefer to stick with merger trees, we find that trees derived from our merger graphs have similar mass growth properties to previous methods, but again without catastrophic failures. For future galaxy formation modelling, two different density thresholds can be used to distinguish host haloes (extended galactic haloes, groups and clusters) from higher-density subhaloes: sites of galaxy formation.
@article{roper_mega_2020,
title = {{MEGA}: {Merger} graphs of structure formation},
shorttitle = {{MEGA}},
url = {http://arxiv.org/abs/2003.01187},
abstract = {When following the growth of structure in the Universe, we propose replacing merger trees with merger graphs, in which haloes can both merge and split into separate pieces. We show that this leads to smoother mass growth and eliminates catastrophic failures in which massive haloes have no progenitors or descendants. For those who prefer to stick with merger trees, we find that trees derived from our merger graphs have similar mass growth properties to previous methods, but again without catastrophic failures. For future galaxy formation modelling, two different density thresholds can be used to distinguish host haloes (extended galactic haloes, groups and clusters) from higher-density subhaloes: sites of galaxy formation.},
urldate = {2020-03-04},
journal = {arXiv:2003.01187 [astro-ph]},
author = {Roper, William J. and Thomas, Peter A. and Srisawat, Chaichalit},
month = mar,
year = {2020},
note = {arXiv: 2003.01187},
keywords = {Astrophysics - Astrophysics of Galaxies, Astrophysics - Cosmology and Nongalactic Astrophysics},
}TARDIS Paper II: Synergistic Density Reconstruction from Lyman-alpha Forest and Spectroscopic Galaxy Surveys with Applications to Protoclusters and the Cosmic Web. Horowitz, B., Zhang, B., Lee, K., & Kooistra, R. arXiv e-prints, 2007:arXiv:2007.15994, July, 2020.
Paper abstract bibtex
Paper abstract bibtex In this work we expand upon the Tomographic Absorption Reconstruction and Density Inference Scheme (TARDIS) in order to include multiple tracers while reconstructing matter density fields at Cosmic Noon (z \textasciitilde 2-3). In particular, we jointly reconstruct the underlying density field from simulated Lyman-Alpha forest observations at \$z{\textbackslash}sim 2.5\$ and an overlapping galaxy survey. We find that these data are synergistic, with the Lyman Alpha forest providing reconstruction of low density regions and galaxy surveys tracing the density peaks. We find a more accurate power spectra reconstruction going to higher scales when fitting these two data-sets simultaneously than if using either one individually. When applied to cosmic web analysis, we find performing the joint analysis is equivalent to a Lyman Alpha survey with significantly increased sight-line spacing. Since we reconstruct the velocity field and matter field jointly, we demonstrate the ability to evolve the mock observed volume further to z=0, allowing us to create a rigorous definition of "proto-cluster" as regions which will evolve into clusters. We apply our reconstructions to study protocluster structure and evolution, finding for realistic survey parameters we can provide accurate mass estimates of the z \textbackslashapprox 2 structures and their z = 0 fate.
@article{horowitz_tardis_2020,
title = {{TARDIS} {Paper} {II}: {Synergistic} {Density} {Reconstruction} from {Lyman}-alpha {Forest} and {Spectroscopic} {Galaxy} {Surveys} with {Applications} to {Protoclusters} and the {Cosmic} {Web}},
volume = {2007},
shorttitle = {{TARDIS} {Paper} {II}},
url = {http://adsabs.harvard.edu/abs/2020arXiv200715994H},
abstract = {In this work we expand upon the Tomographic Absorption Reconstruction
and Density Inference Scheme (TARDIS) in order to include multiple
tracers while reconstructing matter density fields at Cosmic Noon (z {\textasciitilde}
2-3). In particular, we jointly reconstruct the underlying density field
from simulated Lyman-Alpha forest observations at \$z{\textbackslash}sim 2.5\$ and an
overlapping galaxy survey. We find that these data are synergistic, with
the Lyman Alpha forest providing reconstruction of low density regions
and galaxy surveys tracing the density peaks. We find a more accurate
power spectra reconstruction going to higher scales when fitting these
two data-sets simultaneously than if using either one individually. When
applied to cosmic web analysis, we find performing the joint analysis is
equivalent to a Lyman Alpha survey with significantly increased
sight-line spacing. Since we reconstruct the velocity field and matter
field jointly, we demonstrate the ability to evolve the mock observed
volume further to z=0, allowing us to create a rigorous definition of
"proto-cluster" as regions which will evolve into clusters. We apply our
reconstructions to study protocluster structure and evolution, finding
for realistic survey parameters we can provide accurate mass estimates
of the z {\textbackslash}approx 2 structures and their z = 0 fate.},
urldate = {2020-08-04},
journal = {arXiv e-prints},
author = {Horowitz, Benjamin and Zhang, Benjamin and Lee, Khee-Gan and Kooistra, Robin},
month = jul,
year = {2020},
keywords = {Astrophysics - Astrophysics of Galaxies, Astrophysics - Cosmology and Nongalactic Astrophysics},
pages = {arXiv:2007.15994},
}The fate of disk galaxies in IllustrisTNG clusters. Joshi, G. D., Pillepich, A., Nelson, D., Marinacci, F., Springel, V., Rodriguez-Gomez, V., Vogelsberger, M., & Hernquist, L. arXiv e-prints, 2004:arXiv:2004.01191, April, 2020.
Paper abstract bibtex
Paper abstract bibtex We study the stellar morphological evolution of disk galaxies within clusters in the TNG50 and TNG100 runs from the IllustrisTNG simulation suite. We select satellites of masses \$10{\textasciicircum}\{9.7\}{\textless}=M_\{*,z=0\}/M_\{sun\}{\textless}=10{\textasciicircum}\{11.6\}\$ residing in clusters of total masses \$10{\textasciicircum}\{14\}{\textless}=M_\{{\textbackslash}text\{200c,z=0\}\}/M_\{sun\}{\textless}10{\textasciicircum}\{14.6\}\$ at z=0 and study those that were disks at accretion according to a kinematic morphology indicator (the circularity fraction). The galaxies' histories are traced from the time of accretion to \$z=0\$ and compared to a control sample of central galaxies mass-matched at the time of accretion. Most cluster disks become non-disky by z=0, in stark contrast with the control disks, of which a significant fraction remains disky over the same timescales. The transformation to non-disky morphologies is accompanied by gas removal and star formation quenching for both cluster and control galaxies. However, cluster disks that become non-disky by z=0 have lost dark matter (DM) mass and show little growth or a loss of stellar mass, whereas the corresponding control disks show significant growth in both components. Most cluster satellites change their morphologies on similar timescales regardless of stellar mass, in \textasciitilde0.5-4 Gyr after accretion. Cluster disks that have had more numerous and closer pericentric passages show the largest change in morphology. Morphological change in both cluster and control disks requires the presence of a gravitational perturbation to drive stellar orbits to non-disky configurations, along with gas removal/heating to prevent replenishment of the disk through continued star-formation. For cluster disks, the perturbation is in the form of impulsive tidal shocking at pericentres and not tidal stripping of the outer disk stellar material, whereas for control disks, a combination of mergers and AGN feedback appears to be the key driving force behind morphological transformations.
@article{joshi_fate_2020,
title = {The fate of disk galaxies in {IllustrisTNG} clusters},
volume = {2004},
url = {http://adsabs.harvard.edu/abs/2020arXiv200401191J},
abstract = {We study the stellar morphological evolution of disk galaxies within clusters in the TNG50 and TNG100 runs from the IllustrisTNG simulation suite. We select satellites of masses
\$10{\textasciicircum}\{9.7\}{\textless}=M\_\{*,z=0\}/M\_\{sun\}{\textless}=10{\textasciicircum}\{11.6\}\$ residing in clusters of total masses \$10{\textasciicircum}\{14\}{\textless}=M\_\{{\textbackslash}text\{200c,z=0\}\}/M\_\{sun\}{\textless}10{\textasciicircum}\{14.6\}\$ at z=0 and study those that were disks at accretion according to a
kinematic morphology indicator (the circularity fraction). The galaxies' histories are traced from the time of accretion to \$z=0\$ and compared to a control sample of central galaxies mass-matched at the time of accretion. Most cluster disks become non-disky by z=0, in stark contrast with the control disks, of which a significant fraction remains disky over the same timescales. The transformation to non-disky morphologies is accompanied by gas removal and star formation quenching for both cluster and control galaxies. However, cluster disks that become non-disky by z=0 have lost dark matter (DM) mass and show little growth or a loss of stellar mass, whereas the corresponding control disks show significant growth in both components. Most cluster satellites change their morphologies on similar timescales regardless of stellar mass, in {\textasciitilde}0.5-4 Gyr after accretion. Cluster disks that have had more numerous and closer pericentric passages show the largest change in morphology. Morphological change in both cluster and control disks requires the presence of a gravitational perturbation to drive stellar orbits to non-disky configurations, along with gas removal/heating to prevent replenishment of the disk through continued star-formation. For cluster disks, the perturbation is in the form of impulsive tidal shocking at pericentres and not tidal stripping of the outer disk stellar material, whereas for control disks, a combination of mergers and AGN feedback appears to be the key driving force behind morphological
transformations.},
urldate = {2020-04-06},
journal = {arXiv e-prints},
author = {Joshi, Gandhali D. and Pillepich, Annalisa and Nelson, Dylan and Marinacci, Federico and Springel, Volker and Rodriguez-Gomez, Vicente and Vogelsberger, Mark and Hernquist, Lars},
month = apr,
year = {2020},
keywords = {Astrophysics - Astrophysics of Galaxies, Astrophysics - Cosmology and Nongalactic Astrophysics},
pages = {arXiv:2004.01191},
}The UV Luminosity Function of Protocluster Galaxies at \$z{\textbackslash}sim4\$: the Bright-end Excess and the Enhanced Star Formation Rate Density. Ito, K., Kashikawa, N., Toshikawa, J., Overzier, R., Kubo, M., Uchiyama, H., Liang, Y., Onoue, M., Tanaka, M., Komiyama, Y., Lee, C., Lin, Y., Marinello, M., Martin, C. L., & Shibuya, T. arXiv e-prints, 2007:arXiv:2007.02961, July, 2020.
Paper abstract bibtex
Paper abstract bibtex We report the rest-frame ultraviolet luminosity function of \$g\$-dropout galaxies in 177 protocluster candidates (PC UVLF) at \$z{\textbackslash}sim4\$ selected in the Hyper Suprime-Cam Subaru Strategic Program. Comparing with the UVLF of field galaxies at the same redshift, we find that the PC UVLF shows a significant excess towards the bright-end. This excess can not be explained by the contribution of only active galactic nuclei, and we also find that this is more significant in higher dense regions. Assuming that all protocluster members are located on the star formation main sequence, the PC UVLF can be converted into a stellar mass function. Consequently, our protocluster members are inferred to have a 2.8 times more massive characteristic stellar mass than that of the field Lyman break galaxies at the same redshift. This study, for the first time, clearly shows that the enhancement in star formation or stellar mass in overdense regions can generally be seen as early as at \$z{\textbackslash}sim4\$. We also estimate the star formation rate density (SFRD) in protocluster regions as \${\textbackslash}simeq 6-20{\textbackslash}%\$ of the cosmic SFRD, based on the measured PC UVLF after correcting for the selection incompleteness in our protocluster sample. This high value suggests that protoclusters make a non-negligible contribution to the cosmic SFRD at \$z{\textbackslash}sim4\$, as previously suggested by simulations. Our results suggest that protoclusters are essential components for the galaxy evolution at \$z{\textbackslash}sim4\$.
@article{ito_uv_2020,
title = {The {UV} {Luminosity} {Function} of {Protocluster} {Galaxies} at \$z{\textbackslash}sim4\$: the {Bright}-end {Excess} and the {Enhanced} {Star} {Formation} {Rate} {Density}},
volume = {2007},
shorttitle = {The {UV} {Luminosity} {Function} of {Protocluster} {Galaxies} at \$z{\textbackslash}sim4\$},
url = {http://adsabs.harvard.edu/abs/2020arXiv200702961I},
abstract = {We report the rest-frame ultraviolet luminosity function of \$g\$-dropout
galaxies in 177 protocluster candidates (PC UVLF) at \$z{\textbackslash}sim4\$ selected
in the Hyper Suprime-Cam Subaru Strategic Program. Comparing with the
UVLF of field galaxies at the same redshift, we find that the PC UVLF
shows a significant excess towards the bright-end. This excess can not
be explained by the contribution of only active galactic nuclei, and we
also find that this is more significant in higher dense regions.
Assuming that all protocluster members are located on the star formation
main sequence, the PC UVLF can be converted into a stellar mass
function. Consequently, our protocluster members are inferred to have a
2.8 times more massive characteristic stellar mass than that of the
field Lyman break galaxies at the same redshift. This study, for the
first time, clearly shows that the enhancement in star formation or
stellar mass in overdense regions can generally be seen as early as at
\$z{\textbackslash}sim4\$. We also estimate the star formation rate density (SFRD) in
protocluster regions as \${\textbackslash}simeq 6-20{\textbackslash}\%\$ of the cosmic SFRD, based on the
measured PC UVLF after correcting for the selection incompleteness in
our protocluster sample. This high value suggests that protoclusters
make a non-negligible contribution to the cosmic SFRD at \$z{\textbackslash}sim4\$, as
previously suggested by simulations. Our results suggest that
protoclusters are essential components for the galaxy evolution at
\$z{\textbackslash}sim4\$.},
urldate = {2020-07-09},
journal = {arXiv e-prints},
author = {Ito, Kei and Kashikawa, Nobunari and Toshikawa, Jun and Overzier, Roderik and Kubo, Mariko and Uchiyama, Hisakazu and Liang, Yongming and Onoue, Masafusa and Tanaka, Masayuki and Komiyama, Yutaka and Lee, Chien-Hsiu and Lin, Yen-Ting and Marinello, Murilo and Martin, Crystal L. and Shibuya, Takatoshi},
month = jul,
year = {2020},
keywords = {Astrophysics - Astrophysics of Galaxies},
pages = {arXiv:2007.02961},
}The rocky road to quiescence: compaction and quenching of quasar host galaxies at z\textasciitilde2. Stacey, H. R., McKean, J. P., Powell, D. M., Vegetti, S., Rizzo, F., Spingola, C., Auger, M. W., Ivison, R. J., & van der Werf, P. P. arXiv e-prints, 2009:arXiv:2009.01277, September, 2020.
Paper abstract bibtex
Paper abstract bibtex We resolve the host galaxies of seven gravitationally lensed quasars at redshift 1.5 to 2.8 using observations with the Atacama Large (sub-)Millimetre Array. Using a visibility-plane lens modelling technique, we create pixellated reconstructions of the dust morphology, and CO line morphology and kinematics. We find that the quasar hosts in our sample can be distinguished into two types: 1) galaxies characterised by clumpy, extended dust distributions (\$R_\{{\textbackslash}rm eff\}{\textbackslash}sim2\$ kpc) and mean star formation rate surface densities comparable to sub-mm-selected dusty star-forming galaxies (\${\textbackslash}Sigma_\{{\textbackslash}rm SFR\}{\textbackslash}sim5\$ M\$_\{{\textbackslash}odot\}\$ yr\${\textasciicircum}\{-1\}\$ kpc\${\textasciicircum}\{-2\}\$); 2) galaxies that have sizes in dust emission similar to coeval passive galaxies and compact starbursts (\$R_\{{\textbackslash}rm eff\}{\textbackslash}sim0.5\$ kpc), with high mean star formation rate surface densities (\${\textbackslash}Sigma_\{{\textbackslash}rm SFR\}=\$ 40\$-\$2200 M\$_\{{\textbackslash}odot\}\$ yr\${\textasciicircum}\{-1\}\$ kpc\${\textasciicircum}\{-2\}\$) and peak densities of 280\$-\$3700 M\$_\{{\textbackslash}odot\}\$ yr\${\textasciicircum}\{-1\}\$ kpc\${\textasciicircum}\{-2\}\$ that in some cases are Eddington-limited. The small size of some quasar hosts suggests that we observe them at a stage in their transformation into compact spheroids, where a high density of dynamically unstable gas leads to efficient star formation and black hole accretion. For the one system where we probe the mass of the gas reservoir, we find a gas fraction of just \$0.06 {\textbackslash}pm 0.04\$ and a depletion timescale of \$50 {\textbackslash}pm 40\$ Myr, suggesting it is transitioning into quiescence. In general, we expect that the extreme level of star formation in the compact quasar host galaxies will rapidly exhaust their gas reservoirs and could quench with or without help from active galactic nuclei feedback.
@article{stacey_rocky_2020,
title = {The rocky road to quiescence: compaction and quenching of quasar host galaxies at z{\textasciitilde}2},
volume = {2009},
shorttitle = {The rocky road to quiescence},
url = {http://adsabs.harvard.edu/abs/2020arXiv200901277S},
abstract = {We resolve the host galaxies of seven gravitationally lensed quasars at
redshift 1.5 to 2.8 using observations with the Atacama Large
(sub-)Millimetre Array. Using a visibility-plane lens modelling
technique, we create pixellated reconstructions of the dust morphology,
and CO line morphology and kinematics. We find that the quasar hosts in
our sample can be distinguished into two types: 1) galaxies
characterised by clumpy, extended dust distributions (\$R\_\{{\textbackslash}rm eff\}{\textbackslash}sim2\$
kpc) and mean star formation rate surface densities comparable to
sub-mm-selected dusty star-forming galaxies (\${\textbackslash}Sigma\_\{{\textbackslash}rm SFR\}{\textbackslash}sim5\$
M\$\_\{{\textbackslash}odot\}\$ yr\${\textasciicircum}\{-1\}\$ kpc\${\textasciicircum}\{-2\}\$); 2) galaxies that have sizes in dust
emission similar to coeval passive galaxies and compact starbursts
(\$R\_\{{\textbackslash}rm eff\}{\textbackslash}sim0.5\$ kpc), with high mean star formation rate surface
densities (\${\textbackslash}Sigma\_\{{\textbackslash}rm SFR\}=\$ 40\$-\$2200 M\$\_\{{\textbackslash}odot\}\$ yr\${\textasciicircum}\{-1\}\$
kpc\${\textasciicircum}\{-2\}\$) and peak densities of 280\$-\$3700 M\$\_\{{\textbackslash}odot\}\$ yr\${\textasciicircum}\{-1\}\$
kpc\${\textasciicircum}\{-2\}\$ that in some cases are Eddington-limited. The small size of
some quasar hosts suggests that we observe them at a stage in their
transformation into compact spheroids, where a high density of
dynamically unstable gas leads to efficient star formation and black
hole accretion. For the one system where we probe the mass of the gas
reservoir, we find a gas fraction of just \$0.06 {\textbackslash}pm 0.04\$ and a
depletion timescale of \$50 {\textbackslash}pm 40\$ Myr, suggesting it is transitioning
into quiescence. In general, we expect that the extreme level of star
formation in the compact quasar host galaxies will rapidly exhaust their
gas reservoirs and could quench with or without help from active
galactic nuclei feedback.},
urldate = {2020-09-06},
journal = {arXiv e-prints},
author = {Stacey, H. R. and McKean, J. P. and Powell, D. M. and Vegetti, S. and Rizzo, F. and Spingola, C. and Auger, M. W. and Ivison, R. J. and van der Werf, P. P.},
month = sep,
year = {2020},
keywords = {Astrophysics - Astrophysics of Galaxies},
pages = {arXiv:2009.01277},
}Dimensionality Reduction of SDSS Spectra with Variational Autoencoders. Portillo, S. K. N., Parejko, J. K., Vergara, J. R., & Connolly, A. J. The Astronomical Journal, 160:45, July, 2020. ADS Bibcode: 2020AJ....160...45P
Paper doi abstract bibtex
Paper doi abstract bibtex High-resolution galaxy spectra contain much information about galactic physics, but the high dimensionality of these spectra makes it difficult to fully utilize the information they contain. We apply variational autoencoders (VAEs), a nonlinear dimensionality reduction technique, to a sample of spectra from the Sloan Digital Sky Survey (SDSS). In contrast to principal component analysis (PCA), a widely used technique, VAEs can capture nonlinear relationships between latent parameters and the data. We find that a VAE can reconstruct the SDSS spectra well with only six latent parameters, outperforming PCA with the same number of components. Different galaxy classes are naturally separated in this latent space, without class labels having been given to the VAE. The VAE latent space is interpretable because the VAE can be used to make synthetic spectra at any point in latent space. For example, making synthetic spectra along tracks in latent space yields sequences of realistic spectra that interpolate between two different types of galaxies. Using the latent space to find outliers may yield interesting spectra: in our small sample, we immediately find unusual data artifacts and stars misclassified as galaxies. In this exploratory work, we show that VAEs create compact, interpretable latent spaces that capture nonlinear features of the data. While a VAE takes substantial time to train (≍1 day for 48,000 spectra), once trained, VAEs can enable the fast exploration of large astronomical data sets.
@article{portillo_dimensionality_2020,
title = {Dimensionality {Reduction} of {SDSS} {Spectra} with {Variational} {Autoencoders}},
volume = {160},
issn = {0004-6256},
url = {https://ui.adsabs.harvard.edu/abs/2020AJ....160...45P},
doi = {10.3847/1538-3881/ab9644},
abstract = {High-resolution galaxy spectra contain much information about galactic physics, but the high dimensionality of these spectra makes it difficult to fully utilize the information they contain. We apply variational autoencoders (VAEs), a nonlinear dimensionality reduction technique, to a sample of spectra from the Sloan Digital Sky Survey (SDSS). In contrast to principal component analysis (PCA), a widely used technique, VAEs can capture nonlinear relationships between latent parameters and the data. We find that a VAE can reconstruct the SDSS spectra well with only six latent parameters, outperforming PCA with the same number of components. Different galaxy classes are naturally separated in this latent space, without class labels having been given to the VAE. The VAE latent space is interpretable because the VAE can be used to make synthetic spectra at any point in latent space. For example, making synthetic spectra along tracks in latent space yields sequences of realistic spectra that interpolate between two different types of galaxies. Using the latent space to find outliers may yield interesting spectra: in our small sample, we immediately find unusual data artifacts and stars misclassified as galaxies. In this exploratory work, we show that VAEs create compact, interpretable latent spaces that capture nonlinear features of the data. While a VAE takes substantial time to train (≍1 day for 48,000 spectra), once trained, VAEs can enable the fast exploration of large astronomical data sets.},
urldate = {2021-12-10},
journal = {The Astronomical Journal},
author = {Portillo, Stephen K. N. and Parejko, John K. and Vergara, Jorge R. and Connolly, Andrew J.},
month = jul,
year = {2020},
note = {ADS Bibcode: 2020AJ....160...45P},
keywords = {1558, 1933, 1943, 573, 582, 78, Astrophysics - Astrophysics of Galaxies, Astrophysics - Instrumentation and Methods for Astrophysics},
pages = {45},
}A comparison of \${\textbackslash}text\{{H}\}_2\$ formation models at high redshift. Schäbe, A., Romano-Díaz, E., Porciani, C., Ludlow, A. D., & Tomassetti, M. arXiv e-prints, 2003:arXiv:2003.04329, March, 2020.
Paper abstract bibtex
Paper abstract bibtex Modelling the molecular gas that is routinely detected through CO observations of high-redshift galaxies constitutes a major challenge for ab initio simulations of galaxy formation. We carry out a suite of cosmological hydrodynamic simulations in order to compare three approximate methods that have been used in the literature to track the formation and evolution of the simplest and most abundant molecule, H\$_2\$. Namely, we consider: i) a semi-empirical procedure that associates H\$_2\$ to dark-matter haloes based on a series of scaling relations inferred from observations; ii) a model that assumes chemical equilibrium between the H\$_2\$ formation and destruction rates; and iii) a model that fully solves the out-of-equilibrium rate equations and accounts for the unresolved structure of molecular clouds. We study the impact of finite spatial resolution and show that robust H\$_2\$ masses at redshift \$z{\textbackslash}approx 4\$ can only be obtained for galaxies that are sufficiently metal enriched in which H\$_2\$ formation is fast. This corresponds to H\$_2\$ reservoirs with masses \$M_\{{\textbackslash}mathrm\{H_2\}\}{\textbackslash}gtrsim 6{\textbackslash}times 10{\textasciicircum}9 {\textbackslash}mathrm\{M\}_{\textbackslash}odot\$. In this range, equilibrium and non-equilibrium models predict similar molecular masses (but different galaxy morphologies) while the semi-empirical method produces less H\$_2\$. The star-formation rates as well as the stellar and H\$_2\$ masses of the simulated galaxies are in line with those observed in actual galaxies at similar redshifts that are not massive starbursts. The H\$_2\$ mass functions extracted from the simulations at \$z{\textbackslash}approx 4\$ agree well with recent observations that only sample the high-mass end. However, our results indicate that most molecular material at high-\$z\$ lies yet undetected in reservoirs with \$10{\textasciicircum}9
@article{schabe_comparison_2020,
title = {A comparison of \${\textbackslash}text\{{H}\}\_2\$ formation models at high redshift},
volume = {2003},
url = {http://adsabs.harvard.edu/abs/2020arXiv200304329S},
abstract = {Modelling the molecular gas that is routinely detected through CO observations of high-redshift galaxies constitutes a major challenge for ab initio simulations of galaxy formation. We carry out a suite of cosmological hydrodynamic simulations in order to compare three
approximate methods that have been used in the literature to track the formation and evolution of the simplest and most abundant molecule, H\$\_2\$. Namely, we consider: i) a semi-empirical procedure that
associates H\$\_2\$ to dark-matter haloes based on a series of scaling relations inferred from observations; ii) a model that assumes chemical equilibrium between the H\$\_2\$ formation and destruction rates; and iii) a model that fully solves the out-of-equilibrium rate equations and accounts for the unresolved structure of molecular clouds. We study the impact of finite spatial resolution and show that robust H\$\_2\$ masses at redshift \$z{\textbackslash}approx 4\$ can only be obtained for galaxies that are sufficiently metal enriched in which H\$\_2\$ formation is fast. This corresponds to H\$\_2\$ reservoirs with masses \$M\_\{{\textbackslash}mathrm\{H\_2\}\}{\textbackslash}gtrsim 6{\textbackslash}times 10{\textasciicircum}9 {\textbackslash}mathrm\{M\}\_{\textbackslash}odot\$. In this range, equilibrium and
non-equilibrium models predict similar molecular masses (but different galaxy morphologies) while the semi-empirical method produces less H\$\_2\$. The star-formation rates as well as the stellar and H\$\_2\$ masses of the simulated galaxies are in line with those observed in actual galaxies at similar redshifts that are not massive starbursts. The H\$\_2\$ mass functions extracted from the simulations at \$z{\textbackslash}approx 4\$ agree well with recent observations that only sample the high-mass end. However, our results indicate that most molecular material at high-\$z\$ lies yet undetected in reservoirs with \$10{\textasciicircum}9},
urldate = {2020-03-12},
journal = {arXiv e-prints},
author = {Schäbe, Alexander and Romano-Díaz, Emilio and Porciani, Cristiano and Ludlow, Aaron D. and Tomassetti, Matteo},
month = mar,
year = {2020},
keywords = {Astrophysics - Astrophysics of Galaxies},
pages = {arXiv:2003.04329},
}Photometric properties of reionization-epoch galaxies in the SIMBA simulations. Wu, X., Davé, R., Tacchella, S., & Lotz, J. Monthly Notices of the Royal Astronomical Society, 494:5636–5651, April, 2020.
Paper doi abstract bibtex
Paper doi abstract bibtex We study the photometric properties and sizes of the reionization-epoch galaxies in high-resolution SIMBA cosmological hydrodynamical simulations with box sizes of \$[25,50]{\textbackslash}, h{\textasciicircum}\{-1\}{\textbackslash}, \{{\textbackslash}rm Mpc\}\$ . Assuming various attenuation laws, we compute photometry by extincting each star particle's spectrum using the line-of-sight gas metal column density. The predicted ultraviolet luminosity function (UVLF) generally agrees with observations at z = 6, owing to a partial cancellation between the high metallicities of the simulated galaxies and lower dust-to-metal ratios. The simulated z = 8 UVLF is low compared to observations, likely owing to excessive dust extinction. SIMBA predicts UV continuum slopes (β) in agreement with the z = 6 observations, with the best agreement obtained using a Calzetti extinction law. Interestingly, the gas-phase mass-metallicity relation in SIMBA is higher at z ∼ 6 than at z ∼ 2, suggesting that rapid early enrichment (and dust growth) might be necessary to match the observed β. We find that β is more sensitive to the dust extinction law than the UVLF. By generating mock James Webb Space Telescope (JWST) images and analysing in a manner similar to observations, we show that SIMBA's galaxy size-luminosity relation well reproduces the current z = 6 Hubble observations. Unlike observations at lower redshifts, SIMBA predicts similar rest-UV and rest-optical sizes of z = 6 galaxies, owing to weak age gradients and dust extinction in star-forming regions counteract each other to weaken the colour gradients within galaxies. These predictions will be testable with JWST.
@article{wu_photometric_2020,
title = {Photometric properties of reionization-epoch galaxies in the {SIMBA} simulations},
volume = {494},
url = {http://adsabs.harvard.edu/abs/2020MNRAS.494.5636W},
doi = {10.1093/mnras/staa1044},
abstract = {We study the photometric properties and sizes of the reionization-epoch galaxies in high-resolution SIMBA cosmological hydrodynamical
simulations with box sizes of \$[25,50]{\textbackslash}, h{\textasciicircum}\{-1\}{\textbackslash}, \{{\textbackslash}rm Mpc\}\$ . Assuming various attenuation laws, we compute photometry by extincting each star particle's spectrum using the line-of-sight gas metal column density. The predicted ultraviolet luminosity function (UVLF) generally agrees with observations at z = 6, owing to a partial cancellation between the high metallicities of the simulated galaxies and lower dust-to-metal ratios. The simulated z = 8 UVLF is low compared to observations, likely owing to excessive dust extinction. SIMBA predicts UV continuum slopes (β) in agreement with the z = 6 observations, with the best
agreement obtained using a Calzetti extinction law. Interestingly, the gas-phase mass-metallicity relation in SIMBA is higher at z ∼ 6 than at z ∼ 2, suggesting that rapid early enrichment (and dust growth) might be necessary to match the observed β. We find that β is
more sensitive to the dust extinction law than the UVLF. By generating mock James Webb Space Telescope (JWST) images and analysing in a manner similar to observations, we show that SIMBA's galaxy size-luminosity relation well reproduces the current z = 6 Hubble observations. Unlike observations at lower redshifts, SIMBA predicts similar rest-UV and rest-optical sizes of z = 6 galaxies, owing to weak age gradients and dust extinction in star-forming regions counteract each other to weaken the colour gradients within galaxies. These predictions will be testable with JWST.},
urldate = {2020-10-01},
journal = {Monthly Notices of the Royal Astronomical Society},
author = {Wu, Xiaohan and Davé, Romeel and Tacchella, Sandro and Lotz, Jennifer},
month = apr,
year = {2020},
keywords = {Astrophysics - Astrophysics of Galaxies, Astrophysics - Cosmology and Nongalactic Astrophysics, galaxies: evolution, galaxies: formation, galaxies: high-redshift, galaxies: photometry, galaxies: stellar content},
pages = {5636--5651},
}The LOFAR Two-metre Sky Survey Deep fields: The star formation rate - radio luminosity relation at low frequencies. Smith, D. J. B., Haskell, P., Gürkan, G., Best, P. N., Hardcastle, M. J., Kondapally, R., Williams, W., Duncan, K. J., Cochrane, R. K., McCheyne, I., Röttgering, H. J. A., Sabater, J., Shimwell, T. W., Tasse, C., Bonato, M., Bondi, M., Jarvis, M. J., Leslie, S. K., Prandoni, I., & Wang, L. arXiv e-prints, 2011:arXiv:2011.08196, November, 2020.
Paper abstract bibtex
Paper abstract bibtex In this paper, we investigate the relationship between 150MHz luminosity and star formation rate (the SFR-L150 relation) using 150MHz measurements for a near-infrared selected sample of 118,517 \$z{\textless}1\$ galaxies. New radio survey data offer compelling advantages for studying star formation in galaxies, with huge increases in sensitivity, survey speed and resolution over previous generation surveys, and remaining impervious to extinction. The LOFAR Surveys Key Science Project is transforming our understanding of the low-frequency radio sky, with the 150MHz data over the ELAIS-N1 field reaching an RMS sensitivity of 20uJy/beam over 10 deg\${\textasciicircum}2\$ at 6" resolution. All of the galaxies studied have SFR and stellar mass estimates derived from energy balance SED fitting, using redshifts and aperture-matched forced photometry from the LOFAR Two-metre Sky Survey (LoTSS) deep fields data release. The impact of active galactic nuclei is minimised by leveraging the deep ancillary data alongside outlier-resistant median-likelihood methods. We find a linear and non-evolving SFR-L150 relation, apparently consistent with expectations based on calorimetric arguments, down to the lowest SFRs. However, we also recover compelling evidence for stellar mass dependence in line with previous work on this topic, in the sense that higher mass galaxies have a larger 150MHz luminosity at a given SFR, suggesting that the overall agreement with calorimetric arguments may be a coincidence. We conclude that in the absence of AGN, 150MHz observations can be used to measure accurate galaxy SFRs out to \$z=1\$ at least, but it is necessary to account for stellar mass in order to obtain 150MHz-derived SFRs accurate to \textless0.5 dex. Our best-fit relation is \${\textbackslash}log_\{10\} (L_{\textbackslash}mathrm\{150 MHz\} / W{\textbackslash},Hz{\textasciicircum}\{-1\}) = (0.90{\textbackslash}pm 0.01) {\textbackslash}log_\{10\}({\textbackslash}psi/M_{\textbackslash}odot{\textbackslash},{\textbackslash}mathrm\{yr\}{\textasciicircum}\{-1\}) + (0.33 {\textbackslash}pm 0.04) {\textbackslash}log_\{10\} (M/10{\textasciicircum}\{10\}M_{\textbackslash}odot) + 22.22 {\textbackslash}pm 0.02\$. (Abridged)
@article{smith_lofar_2020,
title = {The {LOFAR} {Two}-metre {Sky} {Survey} {Deep} fields: {The} star formation rate - radio luminosity relation at low frequencies},
volume = {2011},
shorttitle = {The {LOFAR} {Two}-metre {Sky} {Survey} {Deep} fields},
url = {http://adsabs.harvard.edu/abs/2020arXiv201108196S},
abstract = {In this paper, we investigate the relationship between 150MHz luminosity
and star formation rate (the SFR-L150 relation) using 150MHz
measurements for a near-infrared selected sample of 118,517 \$z{\textless}1\$
galaxies. New radio survey data offer compelling advantages for studying
star formation in galaxies, with huge increases in sensitivity, survey
speed and resolution over previous generation surveys, and remaining
impervious to extinction. The LOFAR Surveys Key Science Project is
transforming our understanding of the low-frequency radio sky, with the
150MHz data over the ELAIS-N1 field reaching an RMS sensitivity of
20uJy/beam over 10 deg\${\textasciicircum}2\$ at 6" resolution. All of the galaxies studied
have SFR and stellar mass estimates derived from energy balance SED
fitting, using redshifts and aperture-matched forced photometry from the
LOFAR Two-metre Sky Survey (LoTSS) deep fields data release. The impact
of active galactic nuclei is minimised by leveraging the deep ancillary
data alongside outlier-resistant median-likelihood methods. We find a
linear and non-evolving SFR-L150 relation, apparently consistent with
expectations based on calorimetric arguments, down to the lowest SFRs.
However, we also recover compelling evidence for stellar mass dependence
in line with previous work on this topic, in the sense that higher mass
galaxies have a larger 150MHz luminosity at a given SFR, suggesting that
the overall agreement with calorimetric arguments may be a coincidence.
We conclude that in the absence of AGN, 150MHz observations can be used
to measure accurate galaxy SFRs out to \$z=1\$ at least, but it is
necessary to account for stellar mass in order to obtain 150MHz-derived
SFRs accurate to {\textless}0.5 dex. Our best-fit relation is \${\textbackslash}log\_\{10\}
(L\_{\textbackslash}mathrm\{150 MHz\} / W{\textbackslash},Hz{\textasciicircum}\{-1\}) = (0.90{\textbackslash}pm 0.01)
{\textbackslash}log\_\{10\}({\textbackslash}psi/M\_{\textbackslash}odot{\textbackslash},{\textbackslash}mathrm\{yr\}{\textasciicircum}\{-1\}) + (0.33 {\textbackslash}pm 0.04) {\textbackslash}log\_\{10\}
(M/10{\textasciicircum}\{10\}M\_{\textbackslash}odot) + 22.22 {\textbackslash}pm 0.02\$. (Abridged)},
urldate = {2020-11-20},
journal = {arXiv e-prints},
author = {Smith, D. J. B. and Haskell, P. and Gürkan, G. and Best, P. N. and Hardcastle, M. J. and Kondapally, R. and Williams, W. and Duncan, K. J. and Cochrane, R. K. and McCheyne, I. and Röttgering, H. J. A. and Sabater, J. and Shimwell, T. W. and Tasse, C. and Bonato, M. and Bondi, M. and Jarvis, M. J. and Leslie, S. K. and Prandoni, I. and Wang, L.},
month = nov,
year = {2020},
keywords = {Astrophysics - Astrophysics of Galaxies},
pages = {arXiv:2011.08196},
}A Systematic Search for Galaxy Proto-Cluster Cores at \$z{\textbackslash}sim 2\$. Ando, M., Shimasaku, K., & Momose, R. arXiv e-prints, 2002:arXiv:2002.10511, February, 2020.
Paper abstract bibtex
Paper abstract bibtex A proto-cluster core is the most massive dark matter halo (DMH) in a given proto-cluster. To reveal the galaxy formation in core regions, we search for proto-cluster cores at \$z{\textbackslash}sim 2\$ in \${\textbackslash}sim 1.5{\textbackslash}, {\textbackslash}mathrm\{deg\}{\textasciicircum}\{2\}\$ of the COSMOS field. Using pairs of massive galaxies (\${\textbackslash}log(M_\{*\}/M_\{{\textbackslash}odot\}){\textbackslash}geq11\$) as tracers of cores, we find 75 candidate cores, among which 54\textbackslash% are estimated to be real. A clustering analysis finds that these cores have an average DMH mass of \$2.6_\{-0.8\}{\textasciicircum}\{+0.9\}{\textbackslash}times 10{\textasciicircum}\{13\}{\textbackslash}, M_\{{\textbackslash}odot\}\$, or \$4.0_\{-1.5\}{\textasciicircum}\{+1.8\}{\textbackslash}, {\textbackslash}times 10{\textasciicircum}\{13\} M_\{{\textbackslash}odot\}\$ after contamination correction. The extended Press-Schechter model shows that their descendant mass at \$z=0\$ is consistent with Fornax-like or Virgo-like clusters. Moreover, using the IllustrisTNG simulation, we confirm that pairs of massive galaxies are good tracers of DMHs massive enough to be regarded as proto-cluster cores. We then derive the stellar mass function (SMF) and the quiescent fraction for member galaxies of the 75 candidate cores. We find that the core galaxies have a more top-heavy SMF than field galaxies at the same redshift, showing an excess at \${\textbackslash}log(M_\{*\}/M_\{{\textbackslash}odot\}){\textbackslash}gtrsim 10.5\$. The quiescent fraction, \$0.17_\{-0.04\}{\textasciicircum}\{+0.04\}\$ in the mass range \$9.0{\textbackslash}leq {\textbackslash}log(M_\{*\}/M_\{{\textbackslash}odot\}){\textbackslash}leq 11.0\$, is about three times higher than that of field counterparts, giving an environmental quenching efficiency of \$0.13_\{-0.04\}{\textasciicircum}\{+0.04\}\$. These results suggest that stellar mass assembly and quenching are accelerated as early as at \$z{\textbackslash}sim 2\$ in proto-cluster cores.
@article{ando_systematic_2020,
title = {A {Systematic} {Search} for {Galaxy} {Proto}-{Cluster} {Cores} at \$z{\textbackslash}sim 2\$},
volume = {2002},
url = {http://adsabs.harvard.edu/abs/2020arXiv200210511A},
abstract = {A proto-cluster core is the most massive dark matter halo (DMH) in a given proto-cluster. To reveal the galaxy formation in core regions, we search for proto-cluster cores at \$z{\textbackslash}sim 2\$ in \${\textbackslash}sim 1.5{\textbackslash},
{\textbackslash}mathrm\{deg\}{\textasciicircum}\{2\}\$ of the COSMOS field. Using pairs of massive galaxies (\${\textbackslash}log(M\_\{*\}/M\_\{{\textbackslash}odot\}){\textbackslash}geq11\$) as tracers of cores, we find 75
candidate cores, among which 54{\textbackslash}\% are estimated to be real. A clustering analysis finds that these cores have an average DMH mass of
\$2.6\_\{-0.8\}{\textasciicircum}\{+0.9\}{\textbackslash}times 10{\textasciicircum}\{13\}{\textbackslash}, M\_\{{\textbackslash}odot\}\$, or \$4.0\_\{-1.5\}{\textasciicircum}\{+1.8\}{\textbackslash}, {\textbackslash}times 10{\textasciicircum}\{13\} M\_\{{\textbackslash}odot\}\$ after contamination correction. The extended Press-Schechter model shows that their descendant mass at \$z=0\$ is consistent with Fornax-like or Virgo-like clusters. Moreover, using the IllustrisTNG simulation, we confirm that pairs of massive galaxies are good tracers of DMHs massive enough to be regarded as proto-cluster cores. We then derive the stellar mass function (SMF) and the quiescent fraction for member galaxies of the 75 candidate cores. We find that the core galaxies have a more top-heavy SMF than field galaxies at the same redshift, showing an excess at \${\textbackslash}log(M\_\{*\}/M\_\{{\textbackslash}odot\}){\textbackslash}gtrsim 10.5\$. The quiescent fraction, \$0.17\_\{-0.04\}{\textasciicircum}\{+0.04\}\$ in the mass range \$9.0{\textbackslash}leq {\textbackslash}log(M\_\{*\}/M\_\{{\textbackslash}odot\}){\textbackslash}leq 11.0\$, is about three times higher than that of field counterparts, giving an environmental quenching efficiency of \$0.13\_\{-0.04\}{\textasciicircum}\{+0.04\}\$. These results suggest that stellar mass assembly and quenching are accelerated as early as at \$z{\textbackslash}sim 2\$ in proto-cluster cores.},
urldate = {2020-02-28},
journal = {arXiv e-prints},
author = {Ando, Makoto and Shimasaku, Kazuhiro and Momose, Rieko},
month = feb,
year = {2020},
keywords = {Astrophysics - Astrophysics of Galaxies},
pages = {arXiv:2002.10511},
}Redshift evolution of the hot intracluster gas metallicity in the C-EAGLE cluster simulations. Pearce, F. A., Kay, S. T., Barnes, D. J., Bahe, Y. M., & Bower, R. G. arXiv e-prints, 2005:arXiv:2005.12391, May, 2020.
Paper abstract bibtex
Paper abstract bibtex The abundance and distribution of metals in galaxy clusters contains valuable information about their chemical history and evolution. By looking at how metallicity evolves with redshift, it is possible to constrain the different metal production channels. We use the C-EAGLE clusters, a sample of 30 high resolution (\$m_\{gas\} {\textbackslash}simeq 1.8{\textbackslash}times 10{\textasciicircum}\{6\}\$ M\$_\{{\textbackslash}odot\}\$) cluster zoom simulations, to investigate the redshift evolution of metallicity, with particular focus on the cluster outskirts. The early enrichment model, in which the majority of metals are produced in the core of cluster progenitors at high redshift, suggests that metals in cluster outskirts have not significantly evolved since \$z=2\$. With the C-EAGLE sample, we find reasonable agreement with the early enrichment model as there is very little scatter in the metallicity abundance at large radius across the whole sample, out to at least \$z=2\$. The exception is Fe for which the radial dependence of metallicity was found to evolve at low redshift as a result of being mainly produced by Type Ia supernovae, which are more likely to be formed at later times than core-collapse supernovae. We also found considerable redshift evolution of metal abundances in the cores of the C-EAGLE clusters which has not been seen in other simulations or observation based metallicity studies. Since we find this evolution to be driven by accretion of low metallicity gas, it suggests that the interaction between outflowing, AGN heated material and the surrounding gas is important for determining the core abundances in clusters.
@article{pearce_redshift_2020,
title = {Redshift evolution of the hot intracluster gas metallicity in the {C}-{EAGLE} cluster simulations},
volume = {2005},
url = {http://adsabs.harvard.edu/abs/2020arXiv200512391P},
abstract = {The abundance and distribution of metals in galaxy clusters contains
valuable information about their chemical history and evolution. By
looking at how metallicity evolves with redshift, it is possible to
constrain the different metal production channels. We use the C-EAGLE
clusters, a sample of 30 high resolution (\$m\_\{gas\} {\textbackslash}simeq 1.8{\textbackslash}times
10{\textasciicircum}\{6\}\$ M\$\_\{{\textbackslash}odot\}\$) cluster zoom simulations, to investigate the
redshift evolution of metallicity, with particular focus on the cluster
outskirts. The early enrichment model, in which the majority of metals
are produced in the core of cluster progenitors at high redshift,
suggests that metals in cluster outskirts have not significantly evolved
since \$z=2\$. With the C-EAGLE sample, we find reasonable agreement with
the early enrichment model as there is very little scatter in the
metallicity abundance at large radius across the whole sample, out to at
least \$z=2\$. The exception is Fe for which the radial dependence of
metallicity was found to evolve at low redshift as a result of being
mainly produced by Type Ia supernovae, which are more likely to be
formed at later times than core-collapse supernovae. We also found
considerable redshift evolution of metal abundances in the cores of the
C-EAGLE clusters which has not been seen in other simulations or
observation based metallicity studies. Since we find this evolution to
be driven by accretion of low metallicity gas, it suggests that the
interaction between outflowing, AGN heated material and the surrounding
gas is important for determining the core abundances in clusters.},
urldate = {2020-06-04},
journal = {arXiv e-prints},
author = {Pearce, Francesca A. and Kay, Scott T. and Barnes, David J. and Bahe, Yannick M. and Bower, Richard G.},
month = may,
year = {2020},
keywords = {Astrophysics - Astrophysics of Galaxies, Astrophysics - Cosmology and Nongalactic Astrophysics},
pages = {arXiv:2005.12391},
}2019 (9)
A Systematic Search for Reddest Far-infrared and Sub-millimeter Galaxies: revealing dust-embedded starbursts at high redshifts. Yan, H., Ma, Z., Huang, J., & Fan, L. arXiv e-prints, 1912:arXiv:1912.04354, December, 2019.
Paper abstract bibtex
Paper abstract bibtex We present the results of our systematic search for the reddest far-infrared (FIR) and sub-millimeter (sub-mm) galaxies using the data from the Herschel Multi-tiered Extragalactic Survey (HerMES) and the SCUBA2 Cosmological Legacy Survey (S2CLS). The red FIR galaxies are "500 um risers", whose spectral energy distributions (SEDs) increase with wavelength across the three FIR passbands of the Spectral and Photometric Imaging REceiver (SPIRE) at Herschel. Within 106.5 sq.deg of the HerMES fields, we have selected 629 highly reliable 500 um risers. The red sub-mm galaxies are "SPIRE-dropouts", which are prominent detections in the S2CLS 850 um data but are extremely weak or invisible in the SPIRE bands. Within the 2.98 sq.deg common area of HerMES and S2CLS, we have selected 95 such objects. These very red sources could be dusty starbursts at high redshifts (z\textgreater6) because the peak of their cold-dust emission heated by star formation is shifted to the reddest FIR/sub-mm bands. The surface density of 500 um risers is \textasciitilde8.2 per sq.deg at above 20 mJy level in 500 um, while that of SPIRE-dropouts is \textasciitilde 19.3 per sq.deg at above 5 mJy level in 850 um. Using deep radio data in these field, we find that the surface density of z\textgreater6 objects is 5.5 per sq.deg among 500 um risers and is 0.8–13.6 per sq.deg among SPIRE-dropouts. The dust-embedded star formation processes in such objects contribute comparably as Lyman-break galaxies to the global star formation rate density at \$z{\textgreater}6\$.
@article{yan_systematic_2019,
title = {A {Systematic} {Search} for {Reddest} {Far}-infrared and {Sub}-millimeter {Galaxies}: revealing dust-embedded starbursts at high redshifts},
volume = {1912},
shorttitle = {A {Systematic} {Search} for {Reddest} {Far}-infrared and {Sub}-millimeter {Galaxies}},
url = {http://adsabs.harvard.edu/abs/2019arXiv191204354Y},
abstract = {We present the results of our systematic search for the reddest
far-infrared (FIR) and sub-millimeter (sub-mm) galaxies using the data
from the Herschel Multi-tiered Extragalactic Survey (HerMES) and the
SCUBA2 Cosmological Legacy Survey (S2CLS). The red FIR galaxies are "500
um risers", whose spectral energy distributions (SEDs) increase with
wavelength across the three FIR passbands of the Spectral and
Photometric Imaging REceiver (SPIRE) at Herschel. Within 106.5 sq.deg of
the HerMES fields, we have selected 629 highly reliable 500 um risers.
The red sub-mm galaxies are "SPIRE-dropouts", which are prominent
detections in the S2CLS 850 um data but are extremely weak or invisible
in the SPIRE bands. Within the 2.98 sq.deg common area of HerMES and
S2CLS, we have selected 95 such objects. These very red sources could be
dusty starbursts at high redshifts (z{\textgreater}6) because the peak of their
cold-dust emission heated by star formation is shifted to the reddest
FIR/sub-mm bands. The surface density of 500 um risers is {\textasciitilde}8.2 per
sq.deg at above 20 mJy level in 500 um, while that of SPIRE-dropouts is
{\textasciitilde} 19.3 per sq.deg at above 5 mJy level in 850 um. Using deep radio data
in these field, we find that the surface density of z{\textgreater}6 objects is
5.5 per sq.deg among 500 um risers and is 0.8--13.6 per sq.deg among
SPIRE-dropouts. The dust-embedded star formation processes in such
objects contribute comparably as Lyman-break galaxies to the global star
formation rate density at \$z{\textgreater}6\$.},
urldate = {2019-12-12},
journal = {arXiv e-prints},
author = {Yan, Haojing and Ma, Zhiyuan and Huang, Jia-Sheng and Fan, Lulu},
month = dec,
year = {2019},
keywords = {Astrophysics - Astrophysics of Galaxies, High Energy Physics - Experiment},
pages = {arXiv:1912.04354},
}The Global Magneto-Ionic Medium Survey: Polarimetry of the Southern Sky from 300 to 480 MHz. Wolleben, M., Landecker, T., Carretti, E., Dickey, J., Fletcher, A., McClure-Griffiths, N., McConnell, D., Thomson, A., Hill, A., Gaensler, B., Han, J. -., Haverkorn, M., Leahy, J., Reich, W., & Taylor, A. \aj, 158(1):44, July, 2019.
doi bibtex
doi bibtex
@ARTICLE{2019AJ....158...44W,
author = {{Wolleben}, M. and {Landecker}, T.~L. and {Carretti}, E. and {Dickey}, J.~M. and {Fletcher}, A. and {McClure-Griffiths}, N.~M. and {McConnell}, D. and {Thomson}, A.~J.~M. and {Hill}, A.~S. and {Gaensler}, B.~M. and {Han}, J. -L. and {Haverkorn}, M. and {Leahy}, J.~P. and {Reich}, W. and {Taylor}, A.~R.},
title = "{The Global Magneto-Ionic Medium Survey: Polarimetry of the Southern Sky from 300 to 480 MHz}",
journal = {\aj},
keywords = {Galaxy: general, instrumentation: polarimeters, ISM: magnetic fields, radio continuum: ISM, surveys, techniques: polarimetric, Astrophysics - Astrophysics of Galaxies, Astrophysics - Instrumentation and Methods for Astrophysics},
year = 2019,
month = jul,
volume = {158},
number = {1},
eid = {44},
pages = {44},
doi = {10.3847/1538-3881/ab22b0},
archivePrefix = {arXiv},
eprint = {1905.12685},
primaryClass = {astro-ph.GA},
adsurl = {https://ui.adsabs.harvard.edu/abs/2019AJ....158...44W},
adsnote = {Provided by the SAO/NASA Astrophysics Data System}
}Can intrinsic alignments of elongated low-mass galaxies be used to map the cosmic web at high redshift?. Pandya, V., Primack, J., Behroozi, P., Dekel, A., Zhang, H., Eckholm, E., Faber, S. M., Ferguson, H. C., Giavalisco, M., Guo, Y., Hathi, N., Kodra, D., Koo, D., Newman, J., & van der Wel, A. arXiv e-prints, 1902:arXiv:1902.09559, February, 2019.
Paper abstract bibtex
Paper abstract bibtex Hubble Space Telescope observations show that low-mass (\$M_*=10{\textasciicircum}9-10{\textasciicircum}\{10\}M_\{{\textbackslash}odot\}\$) galaxies at high redshift (\$z=1.0-2.5\$) tend to be elongated (prolate) rather than disky (oblate) or spheroidal. This is explained in zoom-in cosmological hydrodynamical simulations by the fact that these galaxies are forming in cosmic web filaments where accretion happens preferentially along the direction of elongation. We ask whether the elongated morphology of these galaxies allows them to be used as effective tracers of cosmic web filaments at high redshift via their intrinsic alignments. Using mock lightcones and spectroscopically-confirmed galaxy pairs from the CANDELS survey, we test two types of alignments: (1) between the galaxy major axis and the direction to nearby galaxies of any mass, and (2) between the major axes of nearby pairs of low-mass, likely prolate, galaxies. The mock lightcones predict strong signals in 3D real space, 3D redshift space, and 2D projected redshift space for both types of alignments, but we do not detect significant alignment signals in CANDELS observations. However, we show that spectroscopic redshifts have been obtained for only a small fraction of highly elongated galaxies, and accounting for spectroscopic incompleteness and redshift errors significantly degrades the 2D mock signal. This may partly explain the alignment discrepancy and highlights one of several avenues for future work.
@article{pandya_can_2019,
title = {Can intrinsic alignments of elongated low-mass galaxies be used to map the cosmic web at high redshift?},
volume = {1902},
url = {http://adsabs.harvard.edu/abs/2019arXiv190209559P},
abstract = {Hubble Space Telescope observations show that low-mass
(\$M\_*=10{\textasciicircum}9-10{\textasciicircum}\{10\}M\_\{{\textbackslash}odot\}\$) galaxies at high redshift (\$z=1.0-2.5\$)
tend to be elongated (prolate) rather than disky (oblate) or spheroidal.
This is explained in zoom-in cosmological hydrodynamical simulations by
the fact that these galaxies are forming in cosmic web filaments where
accretion happens preferentially along the direction of elongation. We
ask whether the elongated morphology of these galaxies allows them to be
used as effective tracers of cosmic web filaments at high redshift via
their intrinsic alignments. Using mock lightcones and
spectroscopically-confirmed galaxy pairs from the CANDELS survey, we
test two types of alignments: (1) between the galaxy major axis and the
direction to nearby galaxies of any mass, and (2) between the major axes
of nearby pairs of low-mass, likely prolate, galaxies. The mock
lightcones predict strong signals in 3D real space, 3D redshift space,
and 2D projected redshift space for both types of alignments, but we do
not detect significant alignment signals in CANDELS observations.
However, we show that spectroscopic redshifts have been obtained for
only a small fraction of highly elongated galaxies, and accounting for
spectroscopic incompleteness and redshift errors significantly degrades
the 2D mock signal. This may partly explain the alignment discrepancy
and highlights one of several avenues for future work.},
urldate = {2019-02-28},
journal = {arXiv e-prints},
author = {Pandya, Viraj and Primack, Joel and Behroozi, Peter and Dekel, Avishai and Zhang, Haowen and Eckholm, Elliot and Faber, Sandra M. and Ferguson, Henry C. and Giavalisco, Mauro and Guo, Yicheng and Hathi, Nimish and Kodra, Dritan and Koo, David and Newman, Jeffrey and van der Wel, Arjen},
month = feb,
year = {2019},
keywords = {Astrophysics - Astrophysics of Galaxies},
pages = {arXiv:1902.09559},
}The Arepo public code release. Weinberger, R., Springel, V., & Pakmor, R. arXiv e-prints, 1909:arXiv:1909.04667, September, 2019.
Paper abstract bibtex
Paper abstract bibtex We introduce the public version of the cosmological magnetohydrodynamical moving-mesh simulation code Arepo. This version contains a finite-volume magnetohydrodynamics algorithm on an unstructured, dynamic Voronoi tessellation coupled to a tree-particle-mesh algorithm for the Poisson equation either on a Newtonian or cosmologically expanding spacetime. Time-integration is performed adopting local timestep constraints for each cell individually, solving the fluxes only across active interfaces, and calculating gravitational forces only between active particles, using an operator-splitting approach. This allows simulations with high dynamic range to be performed efficiently. Arepo is a massively distributed-memory parallel code, using the Message Passing Interface (MPI) communication standard and employing a dynamical work-load and memory balancing scheme to allow optimal use of multi-node parallel computers. The employed parallelization algorithms of Arepo are deterministic and produce binary-identical results when re-run on the same machine and with the same number of MPI ranks. A simple primordial cooling and star formation model is included as an example of sub-resolution models commonly used in simulations of galaxy formation. Arepo also contains a suite of computationally inexpensive test problems, ranging from idealized tests for automated code verification to scaled-down versions of cosmological galaxy formation simulations, and is extensively documented in order to assist adoption of the code by new scientific users.
@article{weinberger_arepo_2019,
title = {The {Arepo} public code release},
volume = {1909},
url = {http://adsabs.harvard.edu/abs/2019arXiv190904667W},
abstract = {We introduce the public version of the cosmological
magnetohydrodynamical moving-mesh simulation code Arepo. This version contains a finite-volume magnetohydrodynamics algorithm on an
unstructured, dynamic Voronoi tessellation coupled to a
tree-particle-mesh algorithm for the Poisson equation either on a Newtonian or cosmologically expanding spacetime. Time-integration is performed adopting local timestep constraints for each cell
individually, solving the fluxes only across active interfaces, and calculating gravitational forces only between active particles, using an operator-splitting approach. This allows simulations with high dynamic range to be performed efficiently. Arepo is a massively
distributed-memory parallel code, using the Message Passing Interface (MPI) communication standard and employing a dynamical work-load and memory balancing scheme to allow optimal use of multi-node parallel computers. The employed parallelization algorithms of Arepo are
deterministic and produce binary-identical results when re-run on the same machine and with the same number of MPI ranks. A simple primordial cooling and star formation model is included as an example of
sub-resolution models commonly used in simulations of galaxy formation. Arepo also contains a suite of computationally inexpensive test
problems, ranging from idealized tests for automated code verification to scaled-down versions of cosmological galaxy formation simulations, and is extensively documented in order to assist adoption of the code by new scientific users.},
urldate = {2019-09-12},
journal = {arXiv e-prints},
author = {Weinberger, Rainer and Springel, Volker and Pakmor, Rüdiger},
month = sep,
year = {2019},
keywords = {Astrophysics - Astrophysics of Galaxies, Astrophysics - Cosmology and Nongalactic Astrophysics, Astrophysics - Instrumentation and Methods for Astrophysics, Physics - Computational Physics},
pages = {arXiv:1909.04667},
}The P\textbackslash'egase.3 code of spectrochemical evolution of galaxies: documentation and complements. Fioc, M. & Rocca-Volmerange, B. arXiv e-prints, 1902:arXiv:1902.02198, February, 2019.
Paper abstract bibtex
Paper abstract bibtex P\textbackslash'egase.3 is a Fortran 95 code modeling the spectral evolution of galaxies from the far-ultraviolet to submillimeter wavelengths. It also follows the chemical evolution of their stars, gas and dust. For a given scenario (a set of parameters defining the history of mass assembly, the star formation law, the initial mass function...), P\textbackslash'egase.3 consistently computes the following: * the star formation, infall, outflow and supernova rates from 0 to 20 Gyr; * the stellar metallicity, the abundances of main elements in the gas and the composition of dust; * the unattenuated stellar spectral energy distribution (SED); * the nebular SED, using nebular continua and emission lines precomputed with code Cloudy (Ferland et al. 2017); * the attenuation in star-forming clouds and the diffuse interstellar medium, by absorption and scattering on dust grains, of the stellar and nebular SEDs. For this, the code uses grids of the transmittance for spiral and spheroidal galaxies. We precomputed these grids through Monte Carlo simulations of radiative transfer based on the method of virtual interactions; * the re-emission by grains of the light they absorbed, taking into account stochastic heating. The main innovation compared to P\textbackslash'egase.2 is the modeling of dust emission and its evolution. The computation of nebular emission has also been entirely upgraded to take into account metallicity effects and infrared lines. Other major differences are that complex scenarios of evolution (derived for instance from cosmological simulations), with several episodes of star formation, infall or outflow, may now be implemented, and that the detailed evolution of the most important elements – not only the overall metallicity – is followed.
@article{fioc_pegase.3_2019,
title = {The {P}{\textbackslash}'egase.3 code of spectrochemical evolution of galaxies: documentation and complements},
volume = {1902},
shorttitle = {The {P}{\textbackslash}'egase.3 code of spectrochemical evolution of galaxies},
url = {http://adsabs.harvard.edu/abs/2019arXiv190202198F},
abstract = {P{\textbackslash}'egase.3 is a Fortran 95 code modeling the spectral evolution of
galaxies from the far-ultraviolet to submillimeter wavelengths. It also
follows the chemical evolution of their stars, gas and dust. For a given
scenario (a set of parameters defining the history of mass assembly, the
star formation law, the initial mass function...), P{\textbackslash}'egase.3
consistently computes the following: * the star formation, infall,
outflow and supernova rates from 0 to 20 Gyr; * the stellar metallicity,
the abundances of main elements in the gas and the composition of dust;
* the unattenuated stellar spectral energy distribution (SED); * the
nebular SED, using nebular continua and emission lines precomputed with
code Cloudy (Ferland et al. 2017); * the attenuation in star-forming
clouds and the diffuse interstellar medium, by absorption and scattering
on dust grains, of the stellar and nebular SEDs. For this, the code uses
grids of the transmittance for spiral and spheroidal galaxies. We
precomputed these grids through Monte Carlo simulations of radiative
transfer based on the method of virtual interactions; * the re-emission
by grains of the light they absorbed, taking into account stochastic
heating. The main innovation compared to P{\textbackslash}'egase.2 is the modeling of
dust emission and its evolution. The computation of nebular emission has
also been entirely upgraded to take into account metallicity effects and
infrared lines. Other major differences are that complex scenarios of
evolution (derived for instance from cosmological simulations), with
several episodes of star formation, infall or outflow, may now be
implemented, and that the detailed evolution of the most important
elements -- not only the overall metallicity -- is followed.},
urldate = {2019-02-08},
journal = {arXiv e-prints},
author = {Fioc, Michel and Rocca-Volmerange, Brigitte},
month = feb,
year = {2019},
keywords = {Astrophysics - Astrophysics of Galaxies, Astrophysics - Instrumentation and Methods for Astrophysics},
pages = {arXiv:1902.02198},
}Searching for the shadows of giants: characterising protoclusters with line of sight Lyman-\\textbackslashalpha\ absorption. Miller, J. S. A., Bolton, J. S., & Hatch, N. arXiv e-prints, 1909:arXiv:1909.02513, September, 2019.
Paper abstract bibtex
Paper abstract bibtex We use state of the art hydrodyamical simulations from the Sherwood, EAGLE and Illustris projects to examine the signature of \$M_\{p̌hantom{\}}{\textbackslash}rm z=0p̌hantom{\{}\}{\textbackslash}simeq 10{\textasciicircum}\{14\}M_\{{\textbackslash}odot\}\$ protoclusters observed in Ly-\${\textbackslash}alpha\$ absorption at \$z{\textbackslash}simeq 2.4\$. We find there is a weak correlation between the mass overdensity, \${\textbackslash}delta_\{{\textbackslash}rm m\}\$, and the Ly-\${\textbackslash}alpha\$ effective optical depth relative to the mean, \${\textbackslash}delta_\{{\textbackslash}tau_{\textbackslash}textrm\{eff\}\}\$, averaged over \$15{\textasciitilde}h{\textasciicircum}\{-1\}{\textbackslash}rm{\textbackslash},cMpc\$ scales, although scatter in the \${\textbackslash}delta_\{{\textbackslash}rm m\}\$–\${\textbackslash}delta_\{{\textbackslash}tau_{\textbackslash}textrm\{eff\}\}\$ plane means it is not possible to uniquely identify large scale overdensities with strong Ly-\${\textbackslash}alpha\$ absorption. Although all protoclusters are associated with large scale mass overdensities, most sight lines through protoclusters in a \${\textbackslash}sim 10{\textasciicircum}\{6\}\$ \${\textbackslash}rm cMpc{\textasciicircum}\{3\}\$ volume probe the low column density Ly-\${\textbackslash}alpha\$ forest. A small subset of sight lines that pass through protoclusters exhibit coherent, strong Ly-\${\textbackslash}alpha\$ absorption on \$15h{\textasciicircum}\{-1\}{\textbackslash}rm{\textbackslash},cMpc\$ scales, although these correspond to a wide range in mass overdensity. Assuming perfect removal of contamination by Ly-\${\textbackslash}alpha\$ absorbers with damping wings, more than half of the remaining sight lines with \${\textbackslash}delta_\{{\textbackslash}tau_\{{\textbackslash}rm eff\}\}{\textgreater}3.5\$ trace protoclusters. It is furthermore possible to identify a model dependent \${\textbackslash}delta_\{{\textbackslash}tau_\{{\textbackslash}rm eff\}\}\$ threshold that selects only protoclusters. However, such regions are rare: excluding absorption caused by damped systems, less than 0.1 per cent of sight lines that pass through a protocluster have \${\textbackslash}delta_\{{\textbackslash}tau_\{{\textbackslash}rm eff\}\}{\textgreater}3.5\$, meaning that any protocluster sample selected in this manner will also be highly incomplete. On the other hand, coherent regions of Ly-\${\textbackslash}alpha\$ absorption also provide a promising route for identifying and studying filamentary environments at high redshift.
@article{miller_searching_2019,
title = {Searching for the shadows of giants: characterising protoclusters with line of sight {Lyman}-\{{\textbackslash}alpha\} absorption},
volume = {1909},
shorttitle = {Searching for the shadows of giants},
url = {http://adsabs.harvard.edu/abs/2019arXiv190902513M},
abstract = {We use state of the art hydrodyamical simulations from the Sherwood,
EAGLE and Illustris projects to examine the signature of \$M\_\{\vphantom{\}}{\textbackslash}rm
z=0\vphantom{\{}\}{\textbackslash}simeq 10{\textasciicircum}\{14\}M\_\{{\textbackslash}odot\}\$ protoclusters observed in Ly-\${\textbackslash}alpha\$
absorption at \$z{\textbackslash}simeq 2.4\$. We find there is a weak correlation between
the mass overdensity, \${\textbackslash}delta\_\{{\textbackslash}rm m\}\$, and the Ly-\${\textbackslash}alpha\$ effective
optical depth relative to the mean, \${\textbackslash}delta\_\{{\textbackslash}tau\_{\textbackslash}textrm\{eff\}\}\$,
averaged over \$15{\textasciitilde}h{\textasciicircum}\{-1\}{\textbackslash}rm{\textbackslash},cMpc\$ scales, although scatter in the
\${\textbackslash}delta\_\{{\textbackslash}rm m\}\$--\${\textbackslash}delta\_\{{\textbackslash}tau\_{\textbackslash}textrm\{eff\}\}\$ plane means it is not
possible to uniquely identify large scale overdensities with strong
Ly-\${\textbackslash}alpha\$ absorption. Although all protoclusters are associated with
large scale mass overdensities, most sight lines through protoclusters
in a \${\textbackslash}sim 10{\textasciicircum}\{6\}\$ \${\textbackslash}rm cMpc{\textasciicircum}\{3\}\$ volume probe the low column density
Ly-\${\textbackslash}alpha\$ forest. A small subset of sight lines that pass through
protoclusters exhibit coherent, strong Ly-\${\textbackslash}alpha\$ absorption on
\$15h{\textasciicircum}\{-1\}{\textbackslash}rm{\textbackslash},cMpc\$ scales, although these correspond to a wide range in
mass overdensity. Assuming perfect removal of contamination by
Ly-\${\textbackslash}alpha\$ absorbers with damping wings, more than half of the
remaining sight lines with \${\textbackslash}delta\_\{{\textbackslash}tau\_\{{\textbackslash}rm eff\}\}{\textgreater}3.5\$ trace
protoclusters. It is furthermore possible to identify a model dependent
\${\textbackslash}delta\_\{{\textbackslash}tau\_\{{\textbackslash}rm eff\}\}\$ threshold that selects only protoclusters.
However, such regions are rare: excluding absorption caused by damped
systems, less than 0.1 per cent of sight lines that pass through a
protocluster have \${\textbackslash}delta\_\{{\textbackslash}tau\_\{{\textbackslash}rm eff\}\}{\textgreater}3.5\$, meaning that any
protocluster sample selected in this manner will also be highly
incomplete. On the other hand, coherent regions of Ly-\${\textbackslash}alpha\$
absorption also provide a promising route for identifying and studying
filamentary environments at high redshift.},
urldate = {2019-09-09},
journal = {arXiv e-prints},
author = {Miller, Joel S. A. and Bolton, James S. and Hatch, Nina},
month = sep,
year = {2019},
keywords = {Astrophysics - Astrophysics of Galaxies, Astrophysics - Cosmology and Nongalactic Astrophysics},
pages = {arXiv:1909.02513},
}The evolution of cold neutral gas and the star formation history. Curran, S. J. arXiv e-prints, 1901:arXiv:1901.06019, January, 2019.
Paper abstract bibtex
Paper abstract bibtex There is a well known disparity between the evolution the star formation rate density, \\textbackslashpsi\*, and the abundance of neutral hydrogen (HI), the raw material for star formation. Recently, however, we have shown that \\textbackslashpsi\* may be correlated with the fraction of cool atomic gas, as traced through the 21-cm absorption of HI. This is expected since star formation requires cold (T \textasciitilde 10 K) gas and so this could address the issue of why the star formation rate density does not trace the bulk atomic gas. The data are, however, limited to redshifts of z \textless 2, where both \\textbackslashpsi\* and the cold gas fraction exhibit a similar steep climb from the present day (z = 0), and so it is unknown whether the cold gas fraction follows the same decline as \\textbackslashpsi\* at higher redshift. In order to address this, we have used unpublished archival observations of 21-cm absorption in high redshift damped Lyman-\\textbackslashalpha\ absorption systems to increase the sample at z \textgreater 2. The data suggest that the cold gas fraction does exhibit a decrease, although this is significantly steeper than \\textbackslashpsi\* at z \textasciitilde 3. This is, however, degenerate with the extents of the absorbing galaxy and the background continuum emission and upon removing these, via canonical evolution models, we find the mean spin temperature of the gas to be \textasciitilde 3000 K, compared to the \textasciitilde2000 K expected from the fit at z \textless 2. These temperatures are consistent with the observed high neutral hydrogen column densities, which require T \textless 4000 K in order for the gas not to be highly ionised.
@article{curran_evolution_2019,
title = {The evolution of cold neutral gas and the star formation history},
volume = {1901},
url = {http://adsabs.harvard.edu/abs/2019arXiv190106019C},
abstract = {There is a well known disparity between the evolution the star formation rate density, \{{\textbackslash}psi\}*, and the abundance of neutral hydrogen (HI), the raw material for star formation. Recently, however, we have shown that \{{\textbackslash}psi\}* may be correlated with the fraction of cool atomic gas, as traced through the 21-cm absorption of HI. This is expected since star formation requires cold (T {\textasciitilde} 10 K) gas and so this could address the issue of why the star formation rate density does not trace the bulk atomic gas. The data are, however, limited to redshifts of z {\textless} 2, where both \{{\textbackslash}psi\}* and the cold gas fraction exhibit a similar steep climb from the present day (z = 0), and so it is unknown whether the cold gas fraction follows the same decline as \{{\textbackslash}psi\}* at higher
redshift. In order to address this, we have used unpublished archival observations of 21-cm absorption in high redshift damped Lyman-\{{\textbackslash}alpha\} absorption systems to increase the sample at z {\textgreater} 2. The data suggest that the cold gas fraction does exhibit a decrease, although this is significantly steeper than \{{\textbackslash}psi\}* at z {\textasciitilde} 3. This is, however,
degenerate with the extents of the absorbing galaxy and the background continuum emission and upon removing these, via canonical evolution models, we find the mean spin temperature of the gas to be {\textasciitilde} 3000 K, compared to the {\textasciitilde}2000 K expected from the fit at z {\textless} 2. These temperatures are consistent with the observed high neutral hydrogen column densities, which require T {\textless} 4000 K in order for the gas not to be highly ionised.},
urldate = {2019-01-21},
journal = {arXiv e-prints},
author = {Curran, S. J.},
month = jan,
year = {2019},
keywords = {Astrophysics - Astrophysics of Galaxies},
pages = {arXiv:1901.06019},
}Rapid early coeval star formation and assembly of the most massive galaxies in the universe. Rennehan, D., Babul, A., Hayward, C. C., Bottrell, C., Hani, M. H., & Chapman, S. C. arXiv e-prints, 1907:arXiv:1907.00977, July, 2019.
Paper abstract bibtex
Paper abstract bibtex The current consensus on the formation and evolution of the brightest cluster galaxies is that their stellar mass forms early (\$z {\textbackslash}gtrsim 4\$) in separate galaxies that then eventually assemble the main structure at late times (\$z {\textbackslash}lesssim 1\$). However, advances in observational techniques have led to the discovery of protoclusters out to \$z {\textbackslash}sim 7\$, suggesting that the late-assembly picture may not be fully complete. Using a combination of observationally constrained hydrodynamical and dark-matter-only simulations, we show that the stellar assembly time of a sub-set of brightest cluster galaxies occurs at high redshifts (\$z {\textgreater} 3\$) rather than at low redshifts (\$z {\textless} 1\$), as is commonly though. We find that highly overdense protoclusters assemble their stellar mass into brightest cluster galaxies within \${\textbackslash}sim 1\$ \${\textbackslash}mathrm\{Gyr\}\$ of evolution – producing massive blue elliptical galaxies at high redshifts (\$z {\textbackslash}gtrsim 3\$). We argue that there is a downsizing effect on the cluster scale wherein the brightest cluster galaxies in the cores of the most-massive clusters assemble earlier than those in lower-mass clusters. The James Webb Space Telescope will be able to detect and confirm our prediction in the near future, and we discuss the implications to constraining the value of \${\textbackslash}sigma_{\textbackslash}mathrm\{8\}\$.
@article{rennehan_rapid_2019,
title = {Rapid early coeval star formation and assembly of the most massive galaxies in the universe},
volume = {1907},
url = {http://adsabs.harvard.edu/abs/2019arXiv190700977R},
abstract = {The current consensus on the formation and evolution of the brightest
cluster galaxies is that their stellar mass forms early (\$z {\textbackslash}gtrsim 4\$)
in separate galaxies that then eventually assemble the main structure at
late times (\$z {\textbackslash}lesssim 1\$). However, advances in observational
techniques have led to the discovery of protoclusters out to \$z {\textbackslash}sim 7\$,
suggesting that the late-assembly picture may not be fully complete.
Using a combination of observationally constrained hydrodynamical and
dark-matter-only simulations, we show that the stellar assembly time of
a sub-set of brightest cluster galaxies occurs at high redshifts (\$z
{\textgreater} 3\$) rather than at low redshifts (\$z {\textless} 1\$), as is commonly
though. We find that highly overdense protoclusters assemble their
stellar mass into brightest cluster galaxies within \${\textbackslash}sim 1\$
\${\textbackslash}mathrm\{Gyr\}\$ of evolution -- producing massive blue elliptical
galaxies at high redshifts (\$z {\textbackslash}gtrsim 3\$). We argue that there is a
downsizing effect on the cluster scale wherein the brightest cluster
galaxies in the cores of the most-massive clusters assemble earlier than
those in lower-mass clusters. The James Webb Space Telescope will be
able to detect and confirm our prediction in the near future, and we
discuss the implications to constraining the value of
\${\textbackslash}sigma\_{\textbackslash}mathrm\{8\}\$.},
urldate = {2019-07-05},
journal = {arXiv e-prints},
author = {Rennehan, Douglas and Babul, Arif and Hayward, Christopher C. and Bottrell, Connor and Hani, Maan H. and Chapman, Scott C.},
month = jul,
year = {2019},
keywords = {Astrophysics - Astrophysics of Galaxies},
pages = {arXiv:1907.00977},
}Detailed dust modelling in the L-GALAXIES semi-analytic model of galaxy formation. Vijayan, A. P., Clay, S. J., Thomas, P. A., Yates, R. M., Wilkins, S. M., & Henriques, B. M. Monthly Notices of the Royal Astronomical Society, 489:4072–4089, November, 2019.
Paper doi abstract bibtex
Paper doi abstract bibtex We implement a detailed dust model into the L-Galaxies semi-analytical model which includes: injection of dust by type II and type Ia supernovae (SNe) and AGB stars; grain growth in molecular clouds; and destruction due to supernova-induced shocks, star formation, and reheating. Our grain growth model follows the dust content in molecular clouds and the inter-cloud medium separately, and allows growth only on pre-existing dust grains. At early times, this can make a significant difference to the dust growth rate. Above z ∼ 8, type II SNe are the primary source of dust, whereas below z ∼ 8, grain growth in molecular clouds dominates, with the total dust content being dominated by the latter below z ∼ 6. However, the detailed history of galaxy formation is important for determining the dust content of any individual galaxy. We introduce a fit to the dust-to-metal (DTM) ratio as a function of metallicity and age, which can be used to deduce the DTM ratio of galaxies at any redshift. At z ≲ 3, we find a fairly flat mean relation between metallicity and the DTM, and a positive correlation between metallicity and the dust-to-gas (DTG) ratio, in good agreement with the shape and normalization of the observed relations. We also match the normalization of the observed stellar mass-dust mass relation over the redshift range of 0-4, and to the dust mass function at z = 0. Our results are important in interpreting observations on the dust content of galaxies across cosmic time, particularly so at high redshift.
@article{vijayan_detailed_2019,
title = {Detailed dust modelling in the {L}-{GALAXIES} semi-analytic model of galaxy formation},
volume = {489},
issn = {0035-8711},
url = {http://adsabs.harvard.edu/abs/2019MNRAS.489.4072V},
doi = {10.1093/mnras/stz1948},
abstract = {We implement a detailed dust model into the L-Galaxies semi-analytical
model which includes: injection of dust by type II and type Ia
supernovae (SNe) and AGB stars; grain growth in molecular clouds; and
destruction due to supernova-induced shocks, star formation, and
reheating. Our grain growth model follows the dust content in molecular
clouds and the inter-cloud medium separately, and allows growth only on
pre-existing dust grains. At early times, this can make a significant
difference to the dust growth rate. Above z ∼ 8, type II SNe are the
primary source of dust, whereas below z ∼ 8, grain growth in
molecular clouds dominates, with the total dust content being dominated
by the latter below z ∼ 6. However, the detailed history of galaxy
formation is important for determining the dust content of any
individual galaxy. We introduce a fit to the dust-to-metal (DTM) ratio
as a function of metallicity and age, which can be used to deduce the
DTM ratio of galaxies at any redshift. At z ≲ 3, we find a fairly
flat mean relation between metallicity and the DTM, and a positive
correlation between metallicity and the dust-to-gas (DTG) ratio, in good
agreement with the shape and normalization of the observed relations. We
also match the normalization of the observed stellar mass-dust mass
relation over the redshift range of 0-4, and to the dust mass function
at z = 0. Our results are important in interpreting observations on the
dust content of galaxies across cosmic time, particularly so at high
redshift.},
urldate = {2020-03-26},
journal = {Monthly Notices of the Royal Astronomical Society},
author = {Vijayan, Aswin P. and Clay, Scott J. and Thomas, Peter A. and Yates, Robert M. and Wilkins, Stephen M. and Henriques, Bruno M.},
month = nov,
year = {2019},
keywords = {Astrophysics - Astrophysics of Galaxies, dust, extinction, galaxies: ISM, galaxies: evolution, galaxies: formation, methods: analytical},
pages = {4072--4089},
}2018 (9)
A tiny host galaxy for the first giant black hole: \$z= 7.5\$ quasar in BlueTides. Tenneti, A., Wilkins, S. M., Di Matteo, T., Croft, R. A. C., & Feng, Y. ArXiv e-prints, 1806:arXiv:1806.00185, June, 2018.
Paper abstract bibtex
Paper abstract bibtex The most distant known quasar recently discovered by Ba\textbackslash\textasciitildenados et al. (2018) is at \$z=7.5\$ (690 Myr after the Big Bang), at the dawn of galaxy formation. We explore the host galaxy of the brightest quasar in the large volume cosmological hydrodynamic simulation BlueTides, which in Phase II has reached these redshifts. The brightest quasar in BlueTides has a luminosity of a \${\textbackslash}sim\$ few \$10{\textasciicircum}\{13\} L_\{{\textbackslash}odot\}\$ and a black hole mass of \$6.4 {\textbackslash}times 10{\textasciicircum}\{8\} M_\{{\textbackslash}odot\}\$ at \$z {\textbackslash}sim 7.5\$, comparable to the observed quasar (the only one in this large volume). The quasar resides in a rare halo of mass \$M_\{H\} {\textbackslash}sim 10{\textasciicircum}\{12\} M_\{{\textbackslash}odot\}\$ and has a host galaxy of stellar mass of \$4 {\textbackslash}times 10{\textasciicircum}\{10\}M_\{{\textbackslash}odot\}\$ with an ongoing (intrinsic) star formation rate of \${\textbackslash}sim 80 M_\{{\textbackslash}odot\} yr{\textasciicircum}\{-1\}\$. The corresponding intrinsic UV magnitude of the galaxy is \$-23.1\$, which is roughly \$2.7\$ magnitudes fainter than the quasar's magnitude of \$-25.9\$. We find that the galaxy is highly metal enriched with a mean metallicity equal to the solar value. We derive quasar and galaxy spectral energy distribution (SED) in the mid and near infrared JWST bands. We predict a significant amount of dust attenuation in the rest-frame UV corresponding to \$A_\{1500\} {\textbackslash}sim 1.7\$ giving an UV based SFR of \${\textbackslash}sim 14 M_\{{\textbackslash}odot\} yr{\textasciicircum}\{-1\}\$. We present mock JWST images of the galaxy with and without central point source, in different MIRI and NIRCam filters. The host galaxy is detectable in NIRCam filters, but it is extremely compact (\$R_\{E\}=0.35\$ kpc). It will require JWST's exquisite sensitivity and resolution to separate the galaxy from the central point source. Finally within the FOV of the quasar in BlueTides there are two more sources that would be detectable by JWST.
@article{tenneti_tiny_2018,
title = {A tiny host galaxy for the first giant black hole: \$z= 7.5\$ quasar in {BlueTides}},
volume = {1806},
shorttitle = {A tiny host galaxy for the first giant black hole},
url = {http://adsabs.harvard.edu/abs/2018arXiv180600185T},
abstract = {The most distant known quasar recently discovered by Ba{\textbackslash}{\textasciitilde}nados et al. (2018) is at \$z=7.5\$ (690 Myr after the Big Bang), at the dawn of galaxy formation. We explore the host galaxy of the brightest quasar in the large volume cosmological hydrodynamic simulation BlueTides, which in Phase II has reached these redshifts. The brightest quasar in BlueTides has a luminosity of a \${\textbackslash}sim\$ few \$10{\textasciicircum}\{13\} L\_\{{\textbackslash}odot\}\$ and a black hole mass of \$6.4 {\textbackslash}times 10{\textasciicircum}\{8\} M\_\{{\textbackslash}odot\}\$ at \$z {\textbackslash}sim 7.5\$, comparable to the observed quasar (the only one in this large volume). The quasar resides in a rare halo of mass \$M\_\{H\} {\textbackslash}sim 10{\textasciicircum}\{12\} M\_\{{\textbackslash}odot\}\$ and has a host galaxy of stellar mass of \$4 {\textbackslash}times 10{\textasciicircum}\{10\}M\_\{{\textbackslash}odot\}\$ with an ongoing (intrinsic) star formation rate of \${\textbackslash}sim 80 M\_\{{\textbackslash}odot\} yr{\textasciicircum}\{-1\}\$. The corresponding intrinsic UV magnitude of the galaxy is \$-23.1\$, which is roughly \$2.7\$ magnitudes fainter than the quasar's magnitude of \$-25.9\$. We find that the galaxy is highly metal enriched with a mean metallicity equal to the solar value. We derive quasar and galaxy spectral energy distribution (SED) in the mid and near infrared JWST bands. We predict a significant amount of dust attenuation in the rest-frame UV
corresponding to \$A\_\{1500\} {\textbackslash}sim 1.7\$ giving an UV based SFR of \${\textbackslash}sim 14 M\_\{{\textbackslash}odot\} yr{\textasciicircum}\{-1\}\$. We present mock JWST images of the galaxy with and without central point source, in different MIRI and NIRCam filters. The host galaxy is detectable in NIRCam filters, but it is extremely compact (\$R\_\{E\}=0.35\$ kpc). It will require JWST's exquisite sensitivity and resolution to separate the galaxy from the central point source. Finally within the FOV of the quasar in BlueTides there are two more sources that would be detectable by JWST.},
urldate = {2018-06-06},
journal = {ArXiv e-prints},
author = {Tenneti, Ananth and Wilkins, Stephen M. and Di Matteo, Tiziana and Croft, Rupert A. C. and Feng, Yu},
month = jun,
year = {2018},
keywords = {Astrophysics - Astrophysics of Galaxies, Astrophysics - Cosmology and Nongalactic Astrophysics},
pages = {arXiv:1806.00185},
}The optical morphologies of galaxies in the IllustrisTNG simulation: a comparison to Pan-STARRS observations. Rodriguez-Gomez, V., Snyder, G. F., Lotz, J. M., Nelson, D., Pillepich, A., Springel, V., Genel, S., Weinberger, R., Tacchella, S., Pakmor, R., Torrey, P., Marinacci, F., Vogelsberger, M., Hernquist, L., & Thilker, D. A. ArXiv e-prints, 1809:arXiv:1809.08239, September, 2018.
Paper abstract bibtex
Paper abstract bibtex We have generated synthetic images of \${\textbackslash}sim\$27,000 galaxies from the IllustrisTNG and the original Illustris hydrodynamic cosmological simulations, designed to match Pan-STARRS observations of \${\textbackslash}log_\{10\}(M_\{{\textbackslash}ast\}/\{{\textbackslash}rm M\}_\{{\textbackslash}odot\}) {\textbackslash}approx 9.8\$-\$11.3\$ galaxies at \$z {\textbackslash}approx 0.05\$. Most of our synthetic images were created with the SKIRT radiative transfer code, including the effects of dust attenuation and scattering, and performing the radiative transfer directly on the Voronoi mesh used by the simulations themselves. We have analysed both our synthetic and real Pan-STARRS images with the newly developed \${\textbackslash}tt\{statmorph\}\$ code, which calculates non-parametric morphological diagnostics – including the Gini-\$M_\{20\}\$ and concentration-asymmetry-smoothness (CAS) statistics – and performs two-dimensional S\textbackslash'\e\rsic fits. Overall, we find that the optical morphologies of IllustrisTNG galaxies are in good agreement with observations, and represent a substantial improvement compared to the original Illustris simulation. In particular, the locus of the Gini-\$M_\{20\}\$ diagram is consistent with that inferred from observations, while the median trends with stellar mass of all the morphological, size and shape parameters considered in this work lie within the \${\textbackslash}sim\$1\${\textbackslash}sigma\$ scatter of the observational trends. However, the IllustrisTNG model has some difficulty with more stringent tests, such as producing a strong morphology-colour relation. This results in a somewhat higher fraction of red discs and blue spheroids compared to observations. Similarly, the morphology-size relation is problematic: while observations show that discs tend to be larger than spheroids at a fixed stellar mass, such a trend is not present in IllustrisTNG.
@article{rodriguez-gomez_optical_2018,
title = {The optical morphologies of galaxies in the {IllustrisTNG} simulation: a comparison to {Pan}-{STARRS} observations},
volume = {1809},
shorttitle = {The optical morphologies of galaxies in the {IllustrisTNG} simulation},
url = {http://adsabs.harvard.edu/abs/2018arXiv180908239R},
abstract = {We have generated synthetic images of \${\textbackslash}sim\$27,000 galaxies from the
IllustrisTNG and the original Illustris hydrodynamic cosmological
simulations, designed to match Pan-STARRS observations of
\${\textbackslash}log\_\{10\}(M\_\{{\textbackslash}ast\}/\{{\textbackslash}rm M\}\_\{{\textbackslash}odot\}) {\textbackslash}approx 9.8\$-\$11.3\$ galaxies at \$z
{\textbackslash}approx 0.05\$. Most of our synthetic images were created with the SKIRT
radiative transfer code, including the effects of dust attenuation and
scattering, and performing the radiative transfer directly on the
Voronoi mesh used by the simulations themselves. We have analysed both
our synthetic and real Pan-STARRS images with the newly developed
\${\textbackslash}tt\{statmorph\}\$ code, which calculates non-parametric morphological
diagnostics -- including the Gini-\$M\_\{20\}\$ and
concentration-asymmetry-smoothness (CAS) statistics -- and performs
two-dimensional S{\textbackslash}'\{e\}rsic fits. Overall, we find that the optical
morphologies of IllustrisTNG galaxies are in good agreement with
observations, and represent a substantial improvement compared to the
original Illustris simulation. In particular, the locus of the
Gini-\$M\_\{20\}\$ diagram is consistent with that inferred from
observations, while the median trends with stellar mass of all the
morphological, size and shape parameters considered in this work lie
within the \${\textbackslash}sim\$1\${\textbackslash}sigma\$ scatter of the observational trends. However,
the IllustrisTNG model has some difficulty with more stringent tests,
such as producing a strong morphology-colour relation. This results in a
somewhat higher fraction of red discs and blue spheroids compared to
observations. Similarly, the morphology-size relation is problematic:
while observations show that discs tend to be larger than spheroids at a
fixed stellar mass, such a trend is not present in IllustrisTNG.},
urldate = {2018-09-25},
journal = {ArXiv e-prints},
author = {Rodriguez-Gomez, Vicente and Snyder, Gregory F. and Lotz, Jennifer M. and Nelson, Dylan and Pillepich, Annalisa and Springel, Volker and Genel, Shy and Weinberger, Rainer and Tacchella, Sandro and Pakmor, Ruediger and Torrey, Paul and Marinacci, Federico and Vogelsberger, Mark and Hernquist, Lars and Thilker, David A.},
month = sep,
year = {2018},
keywords = {Astrophysics - Astrophysics of Galaxies, Astrophysics - Cosmology and Nongalactic Astrophysics},
pages = {arXiv:1809.08239},
}Elevation or Suppression? The Resolved Star Formation Main Sequence of Galaxies with Two Different Assembly Modes. Liu, Q., Wang, E., Lin, Z., Gao, Y., Liu, H., Berhane Teklu, B., & Kong, X. ArXiv e-prints, 1803:arXiv:1803.00319, March, 2018.
Paper abstract bibtex
Paper abstract bibtex We investigate the spatially-resolved star formation main sequence in star-forming galaxies (SFGs) using Integral Field Spectroscopic (IFS) observations from the Mapping Nearby Galaxies at the Apache Point Observatory (MaNGA) survey. We demonstrate that the correlation between the stellar mass surface density (\${\textbackslash}Sigma_*\$) and star formation rate surface density (\${\textbackslash}Sigma_\{{\textbackslash}mathrm\{SFR\}\}\$) holds down to sub-galactic scale, leading to the Sub-Galactic Main Sequence (SGMS). By dividing galaxies into two populations based on their recent mass assembly modes, we find the resolved main sequence in galaxies with 'outside-in' mode is steeper than that in galaxies with 'inside-out' mode. This is also confirmed on a galaxy-by-galaxy level, where we find the distributions of SGMS slopes for individual galaxies are clearly separated for the two populations. When normalizing and stacking the SGMS of individual galaxies on one panel for the two populations, we find the inner regions of galaxies with 'inside-out' mode statistically exhibit a suppression in star formation, with a less significant trend in the outer regions of galaxies with 'outside-in' mode. In contrast, the inner regions of galaxies with 'outside-in' mode and the outer regions of galaxies with 'inside-out' mode follow a slightly sub-linear scaling relation with a slope \${\textbackslash}sim\$0.9, which is in good agreement with previous findings, suggesting that they are experiencing a universal regulation without influences of additional physical processes.
@article{liu_elevation_2018,
title = {Elevation or {Suppression}? {The} {Resolved} {Star} {Formation} {Main} {Sequence} of {Galaxies} with {Two} {Different} {Assembly} {Modes}},
volume = {1803},
shorttitle = {Elevation or {Suppression}?},
url = {http://adsabs.harvard.edu/abs/2018arXiv180300319L},
abstract = {We investigate the spatially-resolved star formation main sequence in
star-forming galaxies (SFGs) using Integral Field Spectroscopic (IFS)
observations from the Mapping Nearby Galaxies at the Apache Point
Observatory (MaNGA) survey. We demonstrate that the correlation between
the stellar mass surface density (\${\textbackslash}Sigma\_*\$) and star formation rate
surface density (\${\textbackslash}Sigma\_\{{\textbackslash}mathrm\{SFR\}\}\$) holds down to sub-galactic
scale, leading to the Sub-Galactic Main Sequence (SGMS). By dividing
galaxies into two populations based on their recent mass assembly modes,
we find the resolved main sequence in galaxies with 'outside-in' mode is
steeper than that in galaxies with 'inside-out' mode. This is also
confirmed on a galaxy-by-galaxy level, where we find the distributions
of SGMS slopes for individual galaxies are clearly separated for the two
populations. When normalizing and stacking the SGMS of individual
galaxies on one panel for the two populations, we find the inner regions
of galaxies with 'inside-out' mode statistically exhibit a suppression
in star formation, with a less significant trend in the outer regions of
galaxies with 'outside-in' mode. In contrast, the inner regions of
galaxies with 'outside-in' mode and the outer regions of galaxies with
'inside-out' mode follow a slightly sub-linear scaling relation with a
slope \${\textbackslash}sim\$0.9, which is in good agreement with previous findings,
suggesting that they are experiencing a universal regulation without
influences of additional physical processes.},
urldate = {2018-04-16},
journal = {ArXiv e-prints},
author = {Liu, Qing and Wang, Enci and Lin, Zesen and Gao, Yulong and Liu, Haiyang and Berhane Teklu, Berzaf and Kong, Xu},
month = mar,
year = {2018},
keywords = {Astrophysics - Astrophysics of Galaxies},
pages = {arXiv:1803.00319},
}The Discovery of A Luminous Broad Absorption Line Quasar at A Redshift of 7.02. Wang, F., Yang, J., Fan, X., Yue, M., Wu, X., Schindler, J., Bian, F., Li, J., Farina, E. P., Bañados, E., Davies, F. B., Decarli, R., Green, R., Jiang, L., Hennawi, J. F., Huang, Y., Mazzuccheli, C., McGreer, I. D., Venemans, B., Walter, F., & Beletsky, Y. ArXiv e-prints, 1810:arXiv:1810.11925, October, 2018.
Paper abstract bibtex
Paper abstract bibtex Despite extensive efforts, only two quasars have been found at \$z{\textgreater}7\$ to date due to a combination of low spatial density and high contamination from more ubiquitous Galactic cool dwarfs in quasar selection. This limits our current knowledge of the super-massive black hole (SMBH) growth mechanism and reionization history. In this letter, we report the discovery of a luminous quasar at \$z=7.021\$, DELS J003836.10\$-\$152723.6 (hereafter J0038\$-\$1527), selected using photometric data from DESI Legacy imaging Survey (DELS), Pan-STARRS1 (PS1) imaging Survey, as well as Wide-field Infrared Survey Explore (\$WISE\$) mid-infrared all-sky survey. With an absolute magnitude of \$M_\{1450\}\$=\$-\$27.1 and bolometric luminosity of \$L_\{p̌hantom{\}}{\textbackslash}rm Bolp̌hantom{\{}\}\$=5.6\${\textbackslash}times\$10\${\textasciicircum}\{13\}\$ \$L_{\textbackslash}odot\$, J0038\$-\$1527 is the most luminous quasar known at \$z{\textgreater}7\$. Deep optical to near infrared spectroscopic observations suggest that J0038-1527 hosts a 1.3 billion solar mass BH accreting at the Eddington limit, with an Eddington ratio of 1.25\${\textbackslash}pm\$0.19. The CIV broad emission line of J0038\$-\$1527 is blue-shifted by more than 3000 km s\${\textasciicircum}\{-1\}\$ to the systemic redshift. More detailed investigations of the high quality spectra reveal three extremely high velocity CIV broad absorption lines (BALs) with velocity from 0.08 to 0.14 times the speed of light and total balnicity index of more than 5000 km s\${\textasciicircum}\{-1\}\$, suggesting the presence of relativistic outflows. J0038\$-\$1527 is the first quasar found at the epoch of reionization (EoR) with such strong outflows and provides a unique laboratory to investigate AGN feedback on the formation and growth of the most massive galaxies in the early universe.
@article{wang_discovery_2018,
title = {The {Discovery} of {A} {Luminous} {Broad} {Absorption} {Line} {Quasar} at {A} {Redshift} of 7.02},
volume = {1810},
url = {http://adsabs.harvard.edu/abs/2018arXiv181011925W},
abstract = {Despite extensive efforts, only two quasars have been found at \$z{\textgreater}7\$ to date due to a combination of low spatial density and high
contamination from more ubiquitous Galactic cool dwarfs in quasar selection. This limits our current knowledge of the super-massive black hole (SMBH) growth mechanism and reionization history. In this letter, we report the discovery of a luminous quasar at \$z=7.021\$, DELS
J003836.10\$-\$152723.6 (hereafter J0038\$-\$1527), selected using
photometric data from DESI Legacy imaging Survey (DELS), Pan-STARRS1 (PS1) imaging Survey, as well as Wide-field Infrared Survey Explore (\$WISE\$) mid-infrared all-sky survey. With an absolute magnitude of \$M\_\{1450\}\$=\$-\$27.1 and bolometric luminosity of \$L\_\{\vphantom{\}}{\textbackslash}rm
Bol\vphantom{\{}\}\$=5.6\${\textbackslash}times\$10\${\textasciicircum}\{13\}\$ \$L\_{\textbackslash}odot\$, J0038\$-\$1527 is the most luminous quasar known at \$z{\textgreater}7\$. Deep optical to near infrared spectroscopic observations suggest that J0038-1527 hosts a 1.3 billion solar mass BH accreting at the Eddington limit, with an Eddington ratio of
1.25\${\textbackslash}pm\$0.19. The CIV broad emission line of J0038\$-\$1527 is
blue-shifted by more than 3000 km s\${\textasciicircum}\{-1\}\$ to the systemic redshift. More detailed investigations of the high quality spectra reveal three extremely high velocity CIV broad absorption lines (BALs) with velocity from 0.08 to 0.14 times the speed of light and total balnicity index of more than 5000 km s\${\textasciicircum}\{-1\}\$, suggesting the presence of relativistic outflows. J0038\$-\$1527 is the first quasar found at the epoch of reionization (EoR) with such strong outflows and provides a unique laboratory to investigate AGN feedback on the formation and growth of the most massive galaxies in the early universe.},
urldate = {2018-11-01},
journal = {ArXiv e-prints},
author = {Wang, Feige and Yang, Jinyi and Fan, Xiaohui and Yue, Minghao and Wu, Xue-Bing and Schindler, Jan-Torge and Bian, Fuyan and Li, Jiang-Tao and Farina, Emanuele P. and Bañados, Eduardo and Davies, Frederick B. and Decarli, Roberto and Green, Richard and Jiang, Linhua and Hennawi, Joseph F. and Huang, Yun-Hsin and Mazzuccheli, Chiara and McGreer, Ian D. and Venemans, Bram and Walter, Fabian and Beletsky, Yuri},
month = oct,
year = {2018},
keywords = {Astrophysics - Astrophysics of Galaxies},
pages = {arXiv:1810.11925},
}Identification of galaxies that experienced a recent major drop of star formation. Ciesla, L., Elbaz, D., Schreiber, C., Daddi, E., & Wang, T. ArXiv e-prints, 1803:arXiv:1803.10239, March, 2018.
Paper abstract bibtex
Paper abstract bibtex [abridged] Building upon a previous study, we define a method to blindly identify galaxies that underwent, and may still be undergoing, a fast downfall of their star-formation activity, that is, a more than 80% drop in star-formation rate (SFR) occurring in less than 500 Myr. Modeling galaxies' SED with a delayed-\${\textbackslash}tau\$ star formation history (SFH), with and without allowing an instantaneous SFR drop within the last hundreds Myr, we isolate 102 candidates out of a subsample of 6,680 galaxies classified as star-forming from the UVJ criterion in the ZFOURGE catalogues. These galaxies are mostly located in the lower part of the SFR-M\$_*\$ main sequence (MS) and extend up to a factor 100 below it. They also lie close to the limit between the passive and active regions on the UVJ diagram, indicating that they are in a transition phase. We show that the selected candidates have different physical properties compared to galaxies with similar UVJ colors, namely, lower star-formation rates and different stellar masses. The morphology of the candidates show no preference for a particular type. Among the 102 candidates, only 4 show signs of an AGN activity (from X-ray luminosity or UV-IR SED fitting decomposition). This low fraction of AGNs among the candidates implies that AGN activity may not be the main driver of the recent downfall, although timescale differences and duty cycle must be taken into account. We finally attempt to recover the past position of these galaxies on the SFR-M\$_*\$ plane, before the downfall of their star-formation and show that some of them were in the starburst region before and are back on the MS. These candidates constitute a promising sample that need more investigation in order to understand the different mechanisms at the origin of the star formation decrease of the Universe since \$z\$\${\textbackslash}sim\$2.
@article{ciesla_identification_2018,
title = {Identification of galaxies that experienced a recent major drop of star formation},
volume = {1803},
url = {http://adsabs.harvard.edu/abs/2018arXiv180310239C},
abstract = {[abridged] Building upon a previous study, we define a method to blindly
identify galaxies that underwent, and may still be undergoing, a fast
downfall of their star-formation activity, that is, a more than 80\% drop
in star-formation rate (SFR) occurring in less than 500 Myr. Modeling
galaxies' SED with a delayed-\${\textbackslash}tau\$ star formation history (SFH), with
and without allowing an instantaneous SFR drop within the last hundreds
Myr, we isolate 102 candidates out of a subsample of 6,680 galaxies
classified as star-forming from the UVJ criterion in the ZFOURGE
catalogues. These galaxies are mostly located in the lower part of the
SFR-M\$\_*\$ main sequence (MS) and extend up to a factor 100 below it.
They also lie close to the limit between the passive and active regions
on the UVJ diagram, indicating that they are in a transition phase. We
show that the selected candidates have different physical properties
compared to galaxies with similar UVJ colors, namely, lower
star-formation rates and different stellar masses. The morphology of the
candidates show no preference for a particular type. Among the 102
candidates, only 4 show signs of an AGN activity (from X-ray luminosity
or UV-IR SED fitting decomposition). This low fraction of AGNs among the
candidates implies that AGN activity may not be the main driver of the
recent downfall, although timescale differences and duty cycle must be
taken into account. We finally attempt to recover the past position of
these galaxies on the SFR-M\$\_*\$ plane, before the downfall of their
star-formation and show that some of them were in the starburst region
before and are back on the MS. These candidates constitute a promising
sample that need more investigation in order to understand the different
mechanisms at the origin of the star formation decrease of the Universe
since \$z\$\${\textbackslash}sim\$2.},
urldate = {2018-04-04},
journal = {ArXiv e-prints},
author = {Ciesla, L. and Elbaz, D. and Schreiber, C. and Daddi, E. and Wang, T.},
month = mar,
year = {2018},
keywords = {Astrophysics - Astrophysics of Galaxies},
pages = {arXiv:1803.10239},
}Could Solar Radiation Pressure Explain 'Oumuamua's Peculiar Acceleration?. Bialy, S. & Loeb, A. ArXiv e-prints, 1810:arXiv:1810.11490, October, 2018.
Paper abstract bibtex
Paper abstract bibtex `Oumuamua (1I/2017 U1) is the first object of interstellar origin observed in the Solar System. Recently, \textbackslashcitet\Micheli2018\ reported that `Oumuamua showed deviations from a Keplerian orbit at a high statistical significance. The observed trajectory is best explained by an excess radial acceleration \${\textbackslash}Delta a {\textbackslash}propto r{\textasciicircum}\{-2\}\$, where \$r\$ is the distance of `Oumuamua from the Sun. Such an acceleration is naturally expected for comets, driven by the evaporating material. However, recent observational and theoretical studies imply that `Oumuamua is not an active comet. We explore the possibility that the excess acceleration results from Solar radiation pressure. The required mass-to-area ratio is \$(m/A){\textbackslash}approx 0.1\$ g cm\${\textasciicircum}\{-2\}\$. For a thin sheet this requires a thickness of \${\textbackslash}approx 0.3-0.9\$ mm. We find that although extremely thin, such an object would survive an interstellar travel over Galactic distances of \${\textbackslash}sim 5\$ kpc, withstanding collisions with gas and dust-grains as well as stresses from rotation and tidal forces. We discuss the possible origins of such an object. Our general results apply to any light probes designed for interstellar travel.
@article{bialy_could_2018,
title = {Could {Solar} {Radiation} {Pressure} {Explain} '{Oumuamua}'s {Peculiar} {Acceleration}?},
volume = {1810},
url = {http://adsabs.harvard.edu/abs/2018arXiv181011490B},
abstract = {`Oumuamua (1I/2017 U1) is the first object of interstellar origin observed in the Solar System. Recently, {\textbackslash}citet\{Micheli2018\} reported that `Oumuamua showed deviations from a Keplerian orbit at a high statistical significance. The observed trajectory is best explained by an excess radial acceleration \${\textbackslash}Delta a {\textbackslash}propto r{\textasciicircum}\{-2\}\$, where \$r\$ is the distance of `Oumuamua from the Sun. Such an acceleration is
naturally expected for comets, driven by the evaporating material. However, recent observational and theoretical studies imply that `Oumuamua is not an active comet. We explore the possibility that the excess acceleration results from Solar radiation pressure. The required mass-to-area ratio is \$(m/A){\textbackslash}approx 0.1\$ g cm\${\textasciicircum}\{-2\}\$. For a thin sheet this requires a thickness of \${\textbackslash}approx 0.3-0.9\$ mm. We find that although extremely thin, such an object would survive an interstellar travel over Galactic distances of \${\textbackslash}sim 5\$ kpc, withstanding collisions with gas and dust-grains as well as stresses from rotation and tidal forces. We discuss the possible origins of such an object. Our general results apply to any light probes designed for interstellar travel.},
urldate = {2018-11-12},
journal = {ArXiv e-prints},
author = {Bialy, Shmuel and Loeb, Abraham},
month = oct,
year = {2018},
keywords = {Astrophysics - Astrophysics of Galaxies, Astrophysics - Earth and Planetary Astrophysics},
pages = {arXiv:1810.11490},
}The Effects of Environment on the Evolution of the Galaxy Stellar Mass Function. Papovich, C., Kawinwanichakij, L., Quadri, R., Glazebrook, K., Labbe, I., Tran, K., Forrest, B., Kacprzak, G. G., Spitler, L. R., Straatman, C. S., & Tomczak, A. arXiv:1801.04934 [astro-ph], January, 2018. arXiv: 1801.04934
Paper abstract bibtex
Paper abstract bibtex We study the effects of galaxy environment on the evolution of the stellar-mass function (SMF) over 0.2 \textless z \textless 2.0 using the FourStar Galaxy Evolution (ZFOURGE) survey and NEWFIRM Medium-Band Survey (NMBS) down to the stellar-mass completeness limit, log M / Msun \textgreater 9.0 (9.5) at z = 1.0 (2.0). We compare the SMFs for quiescent and star-forming galaxies in the highest and lowest environments using a density estimator based on the distance to the galaxies' third-nearest neighbors. For star-forming galaxies, at all redshifts there are only minor differences with environment in the shape of the SMF. For quiescent galaxies, the SMF in the lowest densities shows no evolution with redshift, other than an overall increase in number density (phi*) with time. This suggests that the stellar-mass dependence of quenching in relatively isolated galaxies is both universal and does not evolve strongly. While at z \textgreater\textasciitilde 1.5 the SMF of quiescent galaxies is indistinguishable in the highest and lowest densities, at lower redshifts it shows a rapidly increasing number density of lower-mass galaxies, log M / Msun \textasciitilde= 9-10. We argue this evolution can account for all the redshift evolution in the shape of the total quiescent-galaxy SMF. This evolution in the quiescent-galaxy SMF at higher redshift (z \textgreater 1) requires an environmental-quenching efficiency that decreases with decreasing stellar mass at 0.5 \textless z \textless 1.5 or it would overproduce the number of lower-mass quiescent galaxies in denser environments. This requires a dominant environment process such as starvation combined with rapid gas depletion and ejection at z \textgreater 0.5 - 1.0 for galaxies in our mass range. The efficiency of this process decreases with redshift allowing other processes (such as galaxy interactions and ram-pressure stripping) to become more important at later times, z \textless 0.5.
@article{papovich_effects_2018,
title = {The {Effects} of {Environment} on the {Evolution} of the {Galaxy} {Stellar} {Mass} {Function}},
url = {http://arxiv.org/abs/1801.04934},
abstract = {We study the effects of galaxy environment on the evolution of the stellar-mass function (SMF) over 0.2 {\textless} z {\textless} 2.0 using the FourStar Galaxy Evolution (ZFOURGE) survey and NEWFIRM Medium-Band Survey (NMBS) down to the stellar-mass completeness limit, log M / Msun {\textgreater} 9.0 (9.5) at z = 1.0 (2.0). We compare the SMFs for quiescent and star-forming galaxies in the highest and lowest environments using a density estimator based on the distance to the galaxies' third-nearest neighbors. For star-forming galaxies, at all redshifts there are only minor differences with environment in the shape of the SMF. For quiescent galaxies, the SMF in the lowest densities shows no evolution with redshift, other than an overall increase in number density (phi*) with time. This suggests that the stellar-mass dependence of quenching in relatively isolated galaxies is both universal and does not evolve strongly. While at z {\textgreater}{\textasciitilde} 1.5 the SMF of quiescent galaxies is indistinguishable in the highest and lowest densities, at lower redshifts it shows a rapidly increasing number density of lower-mass galaxies, log M / Msun {\textasciitilde}= 9-10. We argue this evolution can account for all the redshift evolution in the shape of the total quiescent-galaxy SMF. This evolution in the quiescent-galaxy SMF at higher redshift (z {\textgreater} 1) requires an environmental-quenching efficiency that decreases with decreasing stellar mass at 0.5 {\textless} z {\textless} 1.5 or it would overproduce the number of lower-mass quiescent galaxies in denser environments. This requires a dominant environment process such as starvation combined with rapid gas depletion and ejection at z {\textgreater} 0.5 - 1.0 for galaxies in our mass range. The efficiency of this process decreases with redshift allowing other processes (such as galaxy interactions and ram-pressure stripping) to become more important at later times, z {\textless} 0.5.},
urldate = {2018-01-27},
journal = {arXiv:1801.04934 [astro-ph]},
author = {Papovich, Casey and Kawinwanichakij, Lalitwadee and Quadri, Ryan and Glazebrook, Karl and Labbe, Ivo and Tran, Kim-Vy and Forrest, Ben and Kacprzak, Glenn G. and Spitler, Lee R. and Straatman, Caroline S. and Tomczak, Adam},
month = jan,
year = {2018},
note = {arXiv: 1801.04934},
keywords = {Astrophysics - Astrophysics of Galaxies},
}Red Misfits in the Sloan Digital Sky Survey: Properties of Star-forming Red Galaxies. Evans, F. A., Parker, L. C., & Roberts, I. D. ArXiv e-prints, 1803:arXiv:1803.01027, March, 2018.
Paper abstract bibtex
Paper abstract bibtex We study Red Misfits, a population of red, star-forming galaxies in the local Universe. We classify galaxies based on inclination-corrected optical colours and specific star formation rates derived from the Sloan Digital Sky Survey Data Release 7. Although the majority of blue galaxies are star-forming and most red galaxies exhibit little to no ongoing star formation, a small but significant population of galaxies (\${\textbackslash}sim\$11 per cent at all stellar masses) are classified as red in colour yet actively star-forming. We explore a number of properties of these galaxies and demonstrate that Red Misfits are not simply dusty or highly-inclined blue cloud galaxies or quiescent red galaxies with poorly-constrained star formation. The proportion of Red Misfits is nearly independent of environment and this population exhibits both intermediate morphologies and an enhanced likelihood of hosting an AGN. We conclude that Red Misfits are a transition population, gradually quenching on their way to the red sequence and this quenching is dominated by internal processes rather than environmentally-driven processes. We discuss the connection between Red Misfits and other transition galaxy populations, namely S0's, red spirals and green valley galaxies.
@article{evans_red_2018,
title = {Red {Misfits} in the {Sloan} {Digital} {Sky} {Survey}: {Properties} of {Star}-forming {Red} {Galaxies}},
volume = {1803},
shorttitle = {Red {Misfits} in the {Sloan} {Digital} {Sky} {Survey}},
url = {http://adsabs.harvard.edu/abs/2018arXiv180301027E},
abstract = {We study Red Misfits, a population of red, star-forming galaxies in the
local Universe. We classify galaxies based on inclination-corrected
optical colours and specific star formation rates derived from the Sloan
Digital Sky Survey Data Release 7. Although the majority of blue
galaxies are star-forming and most red galaxies exhibit little to no
ongoing star formation, a small but significant population of galaxies
(\${\textbackslash}sim\$11 per cent at all stellar masses) are classified as red in
colour yet actively star-forming. We explore a number of properties of
these galaxies and demonstrate that Red Misfits are not simply dusty or
highly-inclined blue cloud galaxies or quiescent red galaxies with
poorly-constrained star formation. The proportion of Red Misfits is
nearly independent of environment and this population exhibits both
intermediate morphologies and an enhanced likelihood of hosting an AGN.
We conclude that Red Misfits are a transition population, gradually
quenching on their way to the red sequence and this quenching is
dominated by internal processes rather than environmentally-driven
processes. We discuss the connection between Red Misfits and other
transition galaxy populations, namely S0's, red spirals and green valley
galaxies.},
urldate = {2018-03-07},
journal = {ArXiv e-prints},
author = {Evans, Fraser A. and Parker, Laura C. and Roberts, Ian D.},
month = mar,
year = {2018},
keywords = {Astrophysics - Astrophysics of Galaxies},
pages = {arXiv:1803.01027},
}Chaos and Variance in Galaxy Formation. Keller, B. W., Wadsley, J. W., Wang, L., & Kruijssen, J. M. D. ArXiv e-prints, 1803:arXiv:1803.05445, March, 2018.
Paper abstract bibtex
Paper abstract bibtex The evolution of galaxies is governed by equations with chaotic solutions: gravity and compressible hydrodynamics. While this micro-scale chaos and stochasticity has been well studied, it is poorly understood how it couples to macro-scale properties examined in simulations of galaxy formation. In this paper, we show how perturbations introduced by floating-point roundoff, random number generators, and seemingly trivial differences in algorithmic behaviour can produce non-trivial differences in star formation histories, circumgalactic medium (CGM) properties, and the distribution of stellar mass. We examine the importance of stochasticity due to discreteness noise, variations in merger timings and how self-regulation moderates the effects of this stochasticity. We show that chaotic variations in stellar mass can grow until halted by feedback-driven self-regulation or gas exhaustion. We also find that galaxy mergers are critical points from which large (as much as a factor of 2) variations in quantities such as the galaxy stellar mass can grow. These variations can grow and persist for more than a Gyr before regressing towards the mean. These results show that detailed comparisons of simulations require serious consideration of the magnitude of effects compared to run-to-run chaotic variation, and may significantly complicate interpreting the impact of different physical models. Understanding the results of simulations requires us to understand that the process of simulation is not a mapping of an infinitesimal point in configuration space to another, final infinitesimal point. Instead, simulations map a point in a space of possible initial conditions points to a volume of possible final states.
@article{keller_chaos_2018,
title = {Chaos and {Variance} in {Galaxy} {Formation}},
volume = {1803},
url = {http://adsabs.harvard.edu/abs/2018arXiv180305445K},
abstract = {The evolution of galaxies is governed by equations with chaotic solutions: gravity and compressible hydrodynamics. While this
micro-scale chaos and stochasticity has been well studied, it is poorly understood how it couples to macro-scale properties examined in
simulations of galaxy formation. In this paper, we show how
perturbations introduced by floating-point roundoff, random number generators, and seemingly trivial differences in algorithmic behaviour can produce non-trivial differences in star formation histories, circumgalactic medium (CGM) properties, and the distribution of stellar mass. We examine the importance of stochasticity due to discreteness noise, variations in merger timings and how self-regulation moderates the effects of this stochasticity. We show that chaotic variations in stellar mass can grow until halted by feedback-driven self-regulation or gas exhaustion. We also find that galaxy mergers are critical points from which large (as much as a factor of 2) variations in quantities such as the galaxy stellar mass can grow. These variations can grow and persist for more than a Gyr before regressing towards the mean. These results show that detailed comparisons of simulations require serious consideration of the magnitude of effects compared to run-to-run chaotic variation, and may significantly complicate interpreting the impact of different physical models. Understanding the results of simulations requires us to understand that the process of simulation is not a mapping of an infinitesimal point in configuration space to another, final infinitesimal point. Instead, simulations map a point in a space of possible initial conditions points to a volume of possible final states.},
urldate = {2018-04-02},
journal = {ArXiv e-prints},
author = {Keller, B. W. and Wadsley, J. W. and Wang, L. and Kruijssen, J. M. Diederik},
month = mar,
year = {2018},
keywords = {Astrophysics - Astrophysics of Galaxies},
pages = {arXiv:1803.05445},
}2017 (18)
Insights on star formation histories and physical properties of \$1.2 {\textbackslash}leq z {\textbackslash}lesssim 4 \$ Herschel-detected galaxies. Sklias, P., Schaerer, D., Elbaz, D., Pannella, M., Schreiber, C., & Cava, A. ArXiv e-prints, 1705:arXiv:1705.01174, May, 2017.
Paper abstract bibtex
Paper abstract bibtex We test the impact of using variable star forming histories (SFHs) and the use of the IR luminosity (LIR) as a constrain on the physical parameters of high redshift dusty star-forming galaxies. We explore in particular the stellar properties of galaxies in relation with their location on the SFR-M* diagram. We perform SED fitting of the UV-NIR and FIR emissions of a large sample of GOODS-Herschel galaxies, for which rich multi-wavelength observations are available. We test different SFHs and imposing energy conservation in the SED fitting process, to face issues like the age-extinction degeneracy and produce SEDs consistent with observations. Our models work well for the majority of the sample, with the notable exception of the high LIR end, for which we have indications that our simple energy conservation approach cannot hold true. We find trends in the SFHs fitting our sources depending on stellar mass M* and z. Trends also emerge in the characteristic timescales of the SED models depending on the location on the SFR-M* diagram. We show that whilst using the same available observational data, we can produce galaxies less star-forming than usually inferred, if we allow declining SFHs, while properly reproducing their observables. These sources can be post-starbursts undergoing quenching, and their SFRs are potentially overestimated if inferred from their LIR. Fitting without the IR constrain leads to a strong preference for declining SFHs, while its inclusion increases the preference of rising SFHs, more so at high z, in tentative agreement with the cosmic star formation history. Keeping in mind that the sample is biased towards high LIR, the evolution shaped by our model appears as both bursty (initially) and steady-lasting (later on). The global SFH of the sample follows the cosmic SFH with a small scatter, and is compatible with the "downsizing" scenario of galaxy evolution.
@article{sklias_insights_2017,
title = {Insights on star formation histories and physical properties of \$1.2 {\textbackslash}leq z {\textbackslash}lesssim 4 \$ {Herschel}-detected galaxies},
volume = {1705},
url = {http://adsabs.harvard.edu/abs/2017arXiv170501174S},
abstract = {We test the impact of using variable star forming histories (SFHs) and
the use of the IR luminosity (LIR) as a constrain on the physical
parameters of high redshift dusty star-forming galaxies. We explore in
particular the stellar properties of galaxies in relation with their
location on the SFR-M* diagram. We perform SED fitting of the UV-NIR and
FIR emissions of a large sample of GOODS-Herschel galaxies, for which
rich multi-wavelength observations are available. We test different SFHs
and imposing energy conservation in the SED fitting process, to face
issues like the age-extinction degeneracy and produce SEDs consistent
with observations. Our models work well for the majority of the sample,
with the notable exception of the high LIR end, for which we have
indications that our simple energy conservation approach cannot hold
true. We find trends in the SFHs fitting our sources depending on
stellar mass M* and z. Trends also emerge in the characteristic
timescales of the SED models depending on the location on the SFR-M*
diagram. We show that whilst using the same available observational
data, we can produce galaxies less star-forming than usually inferred,
if we allow declining SFHs, while properly reproducing their
observables. These sources can be post-starbursts undergoing quenching,
and their SFRs are potentially overestimated if inferred from their LIR.
Fitting without the IR constrain leads to a strong preference for
declining SFHs, while its inclusion increases the preference of rising
SFHs, more so at high z, in tentative agreement with the cosmic star
formation history. Keeping in mind that the sample is biased towards
high LIR, the evolution shaped by our model appears as both bursty
(initially) and steady-lasting (later on). The global SFH of the sample
follows the cosmic SFH with a small scatter, and is compatible with the
"downsizing" scenario of galaxy evolution.},
urldate = {2017-05-12},
journal = {ArXiv e-prints},
author = {Sklias, P. and Schaerer, D. and Elbaz, D. and Pannella, M. and Schreiber, C. and Cava, A.},
month = may,
year = {2017},
keywords = {Astrophysics - Astrophysics of Galaxies},
pages = {arXiv:1705.01174},
}Interpreting ALMA observations of the ISM during the epoch of reionization. Katz, H., Kimm, T., Sijacki, D., & Haehnelt, M. G. Monthly Notices of the Royal Astronomical Society, 468:4831–4861, July, 2017.
Paper doi abstract bibtex
Paper doi abstract bibtex We present cosmological, radiation-hydrodynamics simulations of galaxy formation during the epoch of reionization in an effort towards modelling the interstellar medium (ISM) and interpreting Atacama Large Millimeter Array (ALMA) observations. Simulations with and without stellar radiation are compared at large (Mpc), intermediate (tens of kpc) and small (sub-kpc) scales. At large scales, the dense regions around galaxies reionize first before ultraviolet (UV) photons penetrate the voids; however, considerable amounts of neutral gas remain present within the haloes. The spatial distribution of neutral gas is highly dynamic and is anticorrelated with the presence of stars older than a few Myr. For our specific feedback implementation, most of the metals remain inside the virial radii of haloes, and they are proportionally distributed over the ionized and neutral media by mass. For our most massive galaxy with Mh ∼ 1011 M⊙, the majority of the C II and O I masses are associated with cold neutral clumps. N II is more diffuse and arises in warmer gas, while O III arises in hotter gas with a higher ionization parameter, produced by photoheating and supernovae. If smaller pockets of high-metallicity gas exist in the ISM, the emission from these ions may be observable by ALMA, while the low metallicity of the galaxy may cause these systems to fall below the local [C II]-star formation rate relation. The presence of dust can cause spatial offsets between UV/Lyman α and [C II] emissions, as suggested by the recent observations of Maiolino et al. [O III] may be spatially offset from both of these components since it arises from a different part of density-temperature phase space.
@article{katz_interpreting_2017,
title = {Interpreting {ALMA} observations of the {ISM} during the epoch of reionization},
volume = {468},
issn = {0035-8711},
url = {http://adsabs.harvard.edu/abs/2017MNRAS.468.4831K},
doi = {10.1093/mnras/stx608},
abstract = {We present cosmological, radiation-hydrodynamics simulations of galaxy formation during the epoch of reionization in an effort towards
modelling the interstellar medium (ISM) and interpreting Atacama Large Millimeter Array (ALMA) observations. Simulations with and without stellar radiation are compared at large (Mpc), intermediate (tens of kpc) and small (sub-kpc) scales. At large scales, the dense regions around galaxies reionize first before ultraviolet (UV) photons penetrate the voids; however, considerable amounts of neutral gas remain present within the haloes. The spatial distribution of neutral gas is highly dynamic and is anticorrelated with the presence of stars older than a few Myr. For our specific feedback implementation, most of the metals remain inside the virial radii of haloes, and they are proportionally distributed over the ionized and neutral media by mass. For our most massive galaxy with Mh ∼ 1011
M⊙, the majority of the C II and O I masses are
associated with cold neutral clumps. N II is more diffuse and arises in warmer gas, while O III arises in hotter gas with a higher ionization parameter, produced by photoheating and supernovae. If smaller pockets of high-metallicity gas exist in the ISM, the emission from these ions may be observable by ALMA, while the low metallicity of the galaxy may cause these systems to fall below the local [C II]-star formation rate relation. The presence of dust can cause spatial offsets between UV/Lyman α and [C II] emissions, as suggested by the recent
observations of Maiolino et al. [O III] may be spatially offset from both of these components since it arises from a different part of density-temperature phase space.},
urldate = {2020-03-26},
journal = {Monthly Notices of the Royal Astronomical Society},
author = {Katz, Harley and Kimm, Taysun and Sijacki, Debora and Haehnelt, Martin G.},
month = jul,
year = {2017},
keywords = {Astrophysics - Astrophysics of Galaxies, galaxies: evolution, galaxies: formation, galaxies: high-redshift, infrared: ISM, intergalactic medium},
pages = {4831--4861},
}The Impact of Redshift on Galaxy Morphometric Classification: case studies for SDSS, DES, LSST and HST with \textbackslashtextsc\Morfometryka\. de Albernaz Ferreira, L. & Ferrari, F. ArXiv e-prints, 1707:arXiv:1707.02863, July, 2017.
Paper abstract bibtex
Paper abstract bibtex We have carried a detailed analysis on the impact of cosmological redshift in the non-parametric approach to automated galaxy morphology classification. We artificially redshifted each galaxy from the EFIGI 4458 sample (re-centered at \$z{\textbackslash}sim 0\$) simulating SDSS, DES, LSST, and HST instruments setups over the range \$0 {\textless} z {\textless} 1.5\$. We then traced how the morphometry is degraded in each \$z\$ using \textbackslashtextsc\Morfometryka\. In the process we re-sampled all catalog to several resolutions and to a diverse SNR range, allowing us to understand the impact of image sampling and noise on our measurements separately. We summarize by exploring the impact of these effects on our capacity to perform automated galaxy supervised morphological classification by investigating the degradation of our classifier's metrics as a function of redshift for each instrument. The overall conclusion is that we can make reliable classification with \textbackslashtextsc\Morfometryka\ for \$z{\textless} 0.2\$ with SDSS, for \$z{\textless}0.5\$ with DES, for \$z{\textless}0.8\$ with LSST and for at least \$z {\textless} 1.5\$ with HST.
@article{de_albernaz_ferreira_impact_2017,
title = {The {Impact} of {Redshift} on {Galaxy} {Morphometric} {Classification}: case studies for {SDSS}, {DES}, {LSST} and {HST} with {\textbackslash}textsc\{{Morfometryka}\}},
volume = {1707},
shorttitle = {The {Impact} of {Redshift} on {Galaxy} {Morphometric} {Classification}},
url = {http://adsabs.harvard.edu/abs/2017arXiv170702863D},
abstract = {We have carried a detailed analysis on the impact of cosmological
redshift in the non-parametric approach to automated galaxy morphology
classification. We artificially redshifted each galaxy from the EFIGI
4458 sample (re-centered at \$z{\textbackslash}sim 0\$) simulating SDSS, DES, LSST, and
HST instruments setups over the range \$0 {\textless} z {\textless} 1.5\$. We then
traced how the morphometry is degraded in each \$z\$ using
{\textbackslash}textsc\{Morfometryka\}. In the process we re-sampled all catalog to
several resolutions and to a diverse SNR range, allowing us to
understand the impact of image sampling and noise on our measurements
separately. We summarize by exploring the impact of these effects on our
capacity to perform automated galaxy supervised morphological
classification by investigating the degradation of our classifier's
metrics as a function of redshift for each instrument. The overall
conclusion is that we can make reliable classification with
{\textbackslash}textsc\{Morfometryka\} for \$z{\textless} 0.2\$ with SDSS, for \$z{\textless}0.5\$ with
DES, for \$z{\textless}0.8\$ with LSST and for at least \$z {\textless} 1.5\$ with HST.},
journal = {ArXiv e-prints},
author = {de Albernaz Ferreira, Leonardo and Ferrari, Fabricio},
month = jul,
year = {2017},
keywords = {Astrophysics - Astrophysics of Galaxies, Astrophysics - Cosmology and Nongalactic Astrophysics, Astrophysics - Instrumentation and Methods for Astrophysics},
pages = {arXiv:1707.02863},
}Luminous Quasars Do Not Live in the Most Overdense Regions of Galaxies at z\textasciitilde4. Uchiyama, H., Toshikawa, J., Kashikawa, N., Overzier, R., Chiang, Y., Tanaka, M., Niino, Y., Ishikawa, S., Onoue, M., Ichikawa, K., Akiyama, M., Coupon, J., Harikane, Y., Imanishi, M., Kodama, T., Komiyama, Y., Lee, C., Lin, Y., Miyazaki, S., Nagao, T., Nishizawa, A. J., Ono, Y., Ouchi, M., Strauss, M., & Wang, S. arXiv:1704.06050 [astro-ph], April, 2017. arXiv: 1704.06050
Paper abstract bibtex
Paper abstract bibtex We present the cross-correlation between 151 luminous quasars (\$M_\{ {\textbackslash}mathrm\{UV\}\} {\textless} -26\$) and 179 protocluster candidates at \$z {\textbackslash}sim 3.8\$, extracted from the Wide imaging survey (\$ {\textbackslash}sim 121{\textasciitilde} \$deg\${\textasciicircum}2\$) performed with a part of the Hyper Suprime-Cam Subaru Strategic Program (HSC-SSP). We find that only two out of 151 quasars reside in regions that are more overdense compared to the average field at \$ {\textgreater} 4 {\textbackslash}sigma \$. The distributions of the distance between quasars and the nearest protoclusters and the significance of the overdensity at the position of quasars are statistically identical to those found for \$g\$-dropout galaxies, suggesting that quasars tend to reside in almost the same environment as star-forming galaxies at this redshift. Using stacking analysis, we find that the average density of \$g\$-dropout galaxies around quasars is slightly higher than that around \$g\$-dropout galaxies on \$1.0 - 2.5\$ pMpc scales, while at \$ {\textless} 0.5\$ pMpc that around quasars tends to be lower. We also find that quasars with higher UV-luminosity or with more massive black holes tend to avoid the most overdense regions, and that the quasar near zone sizes are anti-correlated with overdensity. These findings are consistent with a scenario in which the luminous quasar at \$z {\textbackslash}sim4 \$ resides in structures that are less massive than those expected for the progenitors of today's rich clusters of galaxies, and possibly that luminous quasars may be suppressing star formation in their close vicinity.
@article{uchiyama_luminous_2017,
title = {Luminous {Quasars} {Do} {Not} {Live} in the {Most} {Overdense} {Regions} of {Galaxies} at z{\textasciitilde}4},
url = {http://arxiv.org/abs/1704.06050},
abstract = {We present the cross-correlation between 151 luminous quasars (\$M\_\{ {\textbackslash}mathrm\{UV\}\} {\textless} -26\$) and 179 protocluster candidates at \$z {\textbackslash}sim 3.8\$, extracted from the Wide imaging survey (\$ {\textbackslash}sim 121{\textasciitilde} \$deg\${\textasciicircum}2\$) performed with a part of the Hyper Suprime-Cam Subaru Strategic Program (HSC-SSP). We find that only two out of 151 quasars reside in regions that are more overdense compared to the average field at \$ {\textgreater} 4 {\textbackslash}sigma \$. The distributions of the distance between quasars and the nearest protoclusters and the significance of the overdensity at the position of quasars are statistically identical to those found for \$g\$-dropout galaxies, suggesting that quasars tend to reside in almost the same environment as star-forming galaxies at this redshift. Using stacking analysis, we find that the average density of \$g\$-dropout galaxies around quasars is slightly higher than that around \$g\$-dropout galaxies on \$1.0 - 2.5\$ pMpc scales, while at \$ {\textless} 0.5\$ pMpc that around quasars tends to be lower. We also find that quasars with higher UV-luminosity or with more massive black holes tend to avoid the most overdense regions, and that the quasar near zone sizes are anti-correlated with overdensity. These findings are consistent with a scenario in which the luminous quasar at \$z {\textbackslash}sim4 \$ resides in structures that are less massive than those expected for the progenitors of today's rich clusters of galaxies, and possibly that luminous quasars may be suppressing star formation in their close vicinity.},
urldate = {2017-04-25},
journal = {arXiv:1704.06050 [astro-ph]},
author = {Uchiyama, Hisakazu and Toshikawa, Jun and Kashikawa, Nobunari and Overzier, Roderik and Chiang, Yi-Kuan and Tanaka, Masayuki and Niino, Yuu and Ishikawa, Shogo and Onoue, Masafusa and Ichikawa, Kohei and Akiyama, Masayuki and Coupon, Jean and Harikane, Yuichi and Imanishi, Masatoshi and Kodama, Tadayuki and Komiyama, Yutaka and Lee, Chien-Hsiu and Lin, Yen-Ting and Miyazaki, Satoshi and Nagao, Tohru and Nishizawa, Atushi J. and Ono, Yoshiaki and Ouchi, Masami and Strauss, Michael and Wang, Shiang-Yu},
month = apr,
year = {2017},
note = {arXiv: 1704.06050},
keywords = {Astrophysics - Astrophysics of Galaxies},
}On the far-infrared metallicity diagnostics: applications to high-redshift galaxies. Rigopoulou, D., Pereira-Santaella, M., Magdis, G. E., Cooray, A., Farrah, D., Marques-Chaves, R., Perez-Fournon, , I., & Riechers, D. ArXiv e-prints, 1709:arXiv:1709.07717, September, 2017.
Paper abstract bibtex
Paper abstract bibtex In an earlier paper we modeled the far-infrared emission from a star-forming galaxy using the photoionisation code CLOUDY and presented metallicity sensitive diagnostics based on far-infrared fine structure line ratios. Here, we focus on the applicability of the [OIII]88/[NII]122 microns line ratio as a gas phase metallicity indicator in high redshift submillimetre luminous galaxies. The [OIII]88/[NII]122 microns ratio is strongly dependent on the ionization parameter (which is related to the total number of ionizing photons) as well as the gas electron density. We demonstrate how the ratio of 88/\$122 continuum flux measurements can provide a reasonable estimate of the ionization parameter while the availability of the [NII]205 microns line can constrain the electron density. Using the [OIII]88/[NII]122 microns line ratios from a sample of nearby normal and star-forming galaxies we measure their gas phase metallicities and find that their mass metallicity relation is consistent with the one derived using optical emission lines. Using new, previously unpublished, Herschel spectroscopic observations of key far-infrared fine structure lines of the z{\textasciitilde}3 galaxy HLSW-01 and additional published measurements of far-infrared fine structure lines of high-z submillimetre luminous galaxies we derive gas phase metallicities using their [OIII]88/[NII]122 microns line ratio. We find that the metallicities of these z{\textasciitilde}3 submm luminous galaxies are consistent with solar metallicities and that they appear to follow the mass-metallicity relation expected for z{\textasciitilde}3 systems.
@article{rigopoulou_far-infrared_2017,
title = {On the far-infrared metallicity diagnostics: applications to high-redshift galaxies},
volume = {1709},
shorttitle = {On the far-infrared metallicity diagnostics},
url = {http://adsabs.harvard.edu/abs/2017arXiv170907717R},
abstract = {In an earlier paper we modeled the far-infrared emission from a
star-forming galaxy using the photoionisation code CLOUDY and presented
metallicity sensitive diagnostics based on far-infrared fine structure
line ratios. Here, we focus on the applicability of the
[OIII]88/[NII]122 microns line ratio as a gas phase metallicity
indicator in high redshift submillimetre luminous galaxies. The
[OIII]88/[NII]122 microns ratio is strongly dependent on the ionization
parameter (which is related to the total number of ionizing photons) as
well as the gas electron density. We demonstrate how the ratio of
88/\$122 continuum flux measurements can provide a reasonable estimate of
the ionization parameter while the availability of the [NII]205 microns
line can constrain the electron density. Using the [OIII]88/[NII]122
microns line ratios from a sample of nearby normal and star-forming
galaxies we measure their gas phase metallicities and find that their
mass metallicity relation is consistent with the one derived using
optical emission lines. Using new, previously unpublished, Herschel
spectroscopic observations of key far-infrared fine structure lines of
the z{\textasciitilde}3 galaxy HLSW-01 and additional published measurements of
far-infrared fine structure lines of high-z submillimetre luminous
galaxies we derive gas phase metallicities using their [OIII]88/[NII]122
microns line ratio. We find that the metallicities of these z{\textasciitilde}3 submm
luminous galaxies are consistent with solar metallicities and that they
appear to follow the mass-metallicity relation expected for z{\textasciitilde}3 systems.},
journal = {ArXiv e-prints},
author = {Rigopoulou, D. and Pereira-Santaella, M. and Magdis, G. E. and Cooray, A. and Farrah, D. and Marques-Chaves, R. and Perez-Fournon and, I. and Riechers, D.},
month = sep,
year = {2017},
keywords = {Astrophysics - Astrophysics of Galaxies},
pages = {arXiv:1709.07717},
}A methodology to select galaxies just after the quenching of star formation. Citro, A., Pozzetti, L., Quai, S., Moresco, M., Vallini, L., & Cimatti, A. ArXiv e-prints, 1704:arXiv:1704.05462, April, 2017.
Paper abstract bibtex
Paper abstract bibtex We propose a new methodology aimed at finding star-forming galaxies in the phase which immediately follows the star-formation (SF) quenching, based on the use of high- to low-ionization emission line ratios. These ratios rapidly disappear after the SF halt, due to the softening of the UV ionizing radiation. We focus on [O III] \${\textbackslash}lambda\$5007/H\${\textbackslash}alpha\$ and [Ne III] \${\textbackslash}lambda\$3869/[O II] \${\textbackslash}lambda\$3727, studying them with simulations obtained with the CLOUDY photoionization code. If a sharp quenching is assumed, we find that the two ratios are very sensitive tracers as they drop by a factor \${\textbackslash}sim\$ 10 within \${\textbackslash}sim\$ 10 Myr from the interruption of the SF; instead, if a smoother and slower SF decline is assumed (i.e. an exponentially declining star-formation history with \$e\$-folding time \${\textbackslash}tau=\$ 200 Myr), they decrease by a factor \${\textbackslash}sim\$ 2 within \${\textbackslash}sim\$ 80 Myr. We mitigate the ionization – metallicity degeneracy affecting our methodology using pairs of emission line ratios separately related to metallicity and ionization, adopting the [N II] \${\textbackslash}lambda\$6584/[O II] \${\textbackslash}lambda\$3727 ratio as metallicity diagnostic. Using a Sloan Digital Sky Survey galaxy sample, we identify 10 examples among the most extreme quenching candidates within the [O III] \${\textbackslash}lambda\$5007/H\${\textbackslash}alpha\$ vs. [N II] \${\textbackslash}lambda\$6584/[O II] \${\textbackslash}lambda\$3727 plane, characterized by low [O III] \${\textbackslash}lambda\$5007/H\${\textbackslash}alpha\$, faint [Ne III] \${\textbackslash}lambda\$3869, and by blue dust-corrected spectra and \$(u-r)\$ colours, as expected if the SF quenching has occurred in the very recent past. Our results also suggest that the observed fractions of quenching candidates can be used to constrain the quenching mechanism at work and its time-scales.
@article{citro_methodology_2017,
title = {A methodology to select galaxies just after the quenching of star formation},
volume = {1704},
url = {http://adsabs.harvard.edu/abs/2017arXiv170405462C},
abstract = {We propose a new methodology aimed at finding star-forming galaxies in the phase which immediately follows the star-formation (SF) quenching, based on the use of high- to low-ionization emission line ratios. These ratios rapidly disappear after the SF halt, due to the softening of the UV ionizing radiation. We focus on [O III] \${\textbackslash}lambda\$5007/H\${\textbackslash}alpha\$ and [Ne III] \${\textbackslash}lambda\$3869/[O II] \${\textbackslash}lambda\$3727, studying them with
simulations obtained with the CLOUDY photoionization code. If a sharp quenching is assumed, we find that the two ratios are very sensitive tracers as they drop by a factor \${\textbackslash}sim\$ 10 within \${\textbackslash}sim\$ 10 Myr from the interruption of the SF; instead, if a smoother and slower SF decline is assumed (i.e. an exponentially declining star-formation history with \$e\$-folding time \${\textbackslash}tau=\$ 200 Myr), they decrease by a factor \${\textbackslash}sim\$ 2 within \${\textbackslash}sim\$ 80 Myr. We mitigate the ionization -- metallicity
degeneracy affecting our methodology using pairs of emission line ratios separately related to metallicity and ionization, adopting the [N II] \${\textbackslash}lambda\$6584/[O II] \${\textbackslash}lambda\$3727 ratio as metallicity diagnostic. Using a Sloan Digital Sky Survey galaxy sample, we identify 10 examples among the most extreme quenching candidates within the [O III]
\${\textbackslash}lambda\$5007/H\${\textbackslash}alpha\$ vs. [N II] \${\textbackslash}lambda\$6584/[O II] \${\textbackslash}lambda\$3727 plane, characterized by low [O III] \${\textbackslash}lambda\$5007/H\${\textbackslash}alpha\$, faint [Ne III] \${\textbackslash}lambda\$3869, and by blue dust-corrected spectra and \$(u-r)\$ colours, as expected if the SF quenching has occurred in the very recent past. Our results also suggest that the observed fractions of quenching candidates can be used to constrain the quenching mechanism at work and its time-scales.},
urldate = {2017-04-25},
journal = {ArXiv e-prints},
author = {Citro, Annalisa and Pozzetti, Lucia and Quai, Salvatore and Moresco, Michele and Vallini, Livia and Cimatti, Andrea},
month = apr,
year = {2017},
keywords = {Astrophysics - Astrophysics of Galaxies},
pages = {arXiv:1704.05462},
}Cluster and field elliptical galaxies at z\textasciitilde1.3. The marginal role of the environment and the relevance of the galaxy central regions. Saracco, P., Gargiulo, A., Ciocca, F., & Marchesini, D. Astronomy & Astrophysics, 597:A122, January, 2017. arXiv: 1609.06726
Paper doi abstract bibtex
Paper doi abstract bibtex We compared the properties of 56 elliptical galaxies selected from three clusters at \$1.2{\textless}z{\textless}1.4\$ with those of field galaxies in the GOODS-S (\textasciitilde30), COSMOS (\textasciitilde180) and CANDELS (\textasciitilde220) fields. We studied the relationships among effective radius, surface brightness, stellar mass, stellar mass density \${\textbackslash}Sigma_\{Re\}\$ and central mass density \${\textbackslash}Sigma_\{1kpc\}\$ within 1 kpc radius. We find that cluster ellipticals do not differ from field ellipticals: they share the same structural parameters at fixed mass and the same scaling relations. On the other hand, the population of field ellipticals at \$z{\textbackslash}sim1.3\$ shows a significant lack of massive (\$M_*{\textgreater} 2{\textbackslash}times 10{\textasciicircum}\{11\}\$ M\$_{\textbackslash}odot\$) and large (R\$_e {\textgreater} 4-5\$ kpc) ellipticals with respect to the cluster. Nonetheless, at \$M*{\textless}2{\textbackslash}times 10{\textasciicircum}\{11\}\$ M\$_{\textbackslash}odot\$, the two populations are similar. The size-mass relation of ellipticals at z\textasciitilde1.3 defines two different regimes, above and below a transition mass \$m_t{\textbackslash}sim 2-3{\textbackslash}times10{\textasciicircum}\{10\}\$ M\$_{\textbackslash}odot\$: at lower masses the relation is nearly flat (R\$_e{\textbackslash}propto M_*{\textasciicircum}\{-0.1{\textbackslash}pm 0.2\}\$), the mean radius is constant at \textasciitilde1 kpc and \${\textbackslash}Sigma_\{Re\}{\textbackslash}sim {\textbackslash}Sigma_\{1kpc\}\$ while, at larger masses, the relation is R\$_e{\textbackslash}propto M*{\textasciicircum}\{0.64{\textbackslash}pm0.09\}\$. The transition mass marks the mass at which galaxies reach the maximum \${\textbackslash}Sigma_\{Re\}\$. Also the \${\textbackslash}Sigma_\{1kpc\}\$-mass relation follows two different regimes, \${\textbackslash}Sigma_\{1kpc\}{\textbackslash}propto M*{\textasciicircum}\{0.64{\textbackslash} {\textgreater}m_t\}_\{1.07{\textbackslash} {\textless}m_t\}\$, defining a transition mass density \${\textbackslash}Sigma_\{1kpc\}{\textbackslash}sim 2-3{\textbackslash}times10{\textasciicircum}3\$ M\$_{\textbackslash}odot\$ pc\${\textasciicircum}\{-2\}\$. The mass density \${\textbackslash}Sigma_\{Re\}\$ does not correlate with mass, dense/compact galaxies can be assembled over a wide mass regime, independently of the environment. The central mass density, \${\textbackslash}Sigma_\{1kpc\}\$, besides to be correlated with the mass, is correlated to the age of the stellar population: the higher the central stellar mass density, the higher the mass, the older the age of the stellar population. [Abridged]
@article{saracco_cluster_2017,
title = {Cluster and field elliptical galaxies at z{\textasciitilde}1.3. {The} marginal role of the environment and the relevance of the galaxy central regions},
volume = {597},
issn = {0004-6361, 1432-0746},
url = {http://arxiv.org/abs/1609.06726},
doi = {10.1051/0004-6361/201628866},
abstract = {We compared the properties of 56 elliptical galaxies selected from three clusters at \$1.2{\textless}z{\textless}1.4\$ with those of field galaxies in the GOODS-S ({\textasciitilde}30), COSMOS ({\textasciitilde}180) and CANDELS ({\textasciitilde}220) fields. We studied the relationships among effective radius, surface brightness, stellar mass, stellar mass density \${\textbackslash}Sigma\_\{Re\}\$ and central mass density \${\textbackslash}Sigma\_\{1kpc\}\$ within 1 kpc radius. We find that cluster ellipticals do not differ from field ellipticals: they share the same structural parameters at fixed mass and the same scaling relations. On the other hand, the population of field ellipticals at \$z{\textbackslash}sim1.3\$ shows a significant lack of massive (\$M\_*{\textgreater} 2{\textbackslash}times 10{\textasciicircum}\{11\}\$ M\$\_{\textbackslash}odot\$) and large (R\$\_e {\textgreater} 4-5\$ kpc) ellipticals with respect to the cluster. Nonetheless, at \$M*{\textless}2{\textbackslash}times 10{\textasciicircum}\{11\}\$ M\$\_{\textbackslash}odot\$, the two populations are similar. The size-mass relation of ellipticals at z{\textasciitilde}1.3 defines two different regimes, above and below a transition mass \$m\_t{\textbackslash}sim 2-3{\textbackslash}times10{\textasciicircum}\{10\}\$ M\$\_{\textbackslash}odot\$: at lower masses the relation is nearly flat (R\$\_e{\textbackslash}propto M\_*{\textasciicircum}\{-0.1{\textbackslash}pm 0.2\}\$), the mean radius is constant at {\textasciitilde}1 kpc and \${\textbackslash}Sigma\_\{Re\}{\textbackslash}sim {\textbackslash}Sigma\_\{1kpc\}\$ while, at larger masses, the relation is R\$\_e{\textbackslash}propto M*{\textasciicircum}\{0.64{\textbackslash}pm0.09\}\$. The transition mass marks the mass at which galaxies reach the maximum \${\textbackslash}Sigma\_\{Re\}\$. Also the \${\textbackslash}Sigma\_\{1kpc\}\$-mass relation follows two different regimes, \${\textbackslash}Sigma\_\{1kpc\}{\textbackslash}propto M*{\textasciicircum}\{0.64{\textbackslash} {\textgreater}m\_t\}\_\{1.07{\textbackslash} {\textless}m\_t\}\$, defining a transition mass density \${\textbackslash}Sigma\_\{1kpc\}{\textbackslash}sim 2-3{\textbackslash}times10{\textasciicircum}3\$ M\$\_{\textbackslash}odot\$ pc\${\textasciicircum}\{-2\}\$. The mass density \${\textbackslash}Sigma\_\{Re\}\$ does not correlate with mass, dense/compact galaxies can be assembled over a wide mass regime, independently of the environment. The central mass density, \${\textbackslash}Sigma\_\{1kpc\}\$, besides to be correlated with the mass, is correlated to the age of the stellar population: the higher the central stellar mass density, the higher the mass, the older the age of the stellar population. [Abridged]},
journal = {Astronomy \& Astrophysics},
author = {Saracco, P. and Gargiulo, A. and Ciocca, F. and Marchesini, D.},
month = jan,
year = {2017},
note = {arXiv: 1609.06726},
keywords = {Astrophysics - Astrophysics of Galaxies},
pages = {A122},
}An alternate approach to measure specific star formation rates at 2. Davidzon, I., Ilbert, O., Faisst, A. L., Sparre, M., & Capak, P. L. ArXiv e-prints, 1712:arXiv:1712.03959, December, 2017.
Paper abstract bibtex
Paper abstract bibtex We trace the specific star formation rate (sSFR) of massive star-forming galaxies (\${\textbackslash}gtrsim{\textbackslash}!10{\textasciicircum}\{10\}{\textbackslash},{\textbackslash}mathcal\{M\}_{\textbackslash}odot\$) from \$z{\textbackslash}sim2\$ to 7. Our method is substantially different from previous analyses, as it does not rely on direct estimates of star formation rate, but on the differential evolution of the galaxy stellar mass function (SMF). We show the reliability of this approach by means of semi-analytical and hydrodynamical cosmological simulations. We then apply it to real data, using the SMFs derived in the COSMOS and CANDELS fields. We find that the sSFR is proportional to \$(1+z){\textasciicircum}\{1.1{\textbackslash}pm0.2\}\$ at \$z{\textgreater}2\$, in agreement with other observations but in tension with the steeper evolution predicted by simulations from \$z{\textbackslash}sim4\$ to 2. We investigate the impact of several sources of observational bias, which however cannot account for this discrepancy. Although the SMF of high-redshift galaxies is still affected by significant errors, we show that future large-area surveys will substantially reduce them, making our method an effective tool to probe the massive end of the main sequence of star-forming galaxies.
@article{davidzon_alternate_2017,
title = {An alternate approach to measure specific star formation rates at 2},
volume = {1712},
url = {http://adsabs.harvard.edu/abs/2017arXiv171203959D},
abstract = {We trace the specific star formation rate (sSFR) of massive star-forming galaxies (\${\textbackslash}gtrsim{\textbackslash}!10{\textasciicircum}\{10\}{\textbackslash},{\textbackslash}mathcal\{M\}\_{\textbackslash}odot\$) from \$z{\textbackslash}sim2\$ to 7. Our method is substantially different from previous analyses, as it does not rely on direct estimates of star formation rate, but on the differential evolution of the galaxy stellar mass function (SMF). We show the reliability of this approach by means of semi-analytical and
hydrodynamical cosmological simulations. We then apply it to real data, using the SMFs derived in the COSMOS and CANDELS fields. We find that the sSFR is proportional to \$(1+z){\textasciicircum}\{1.1{\textbackslash}pm0.2\}\$ at \$z{\textgreater}2\$, in
agreement with other observations but in tension with the steeper evolution predicted by simulations from \$z{\textbackslash}sim4\$ to 2. We investigate the impact of several sources of observational bias, which however cannot account for this discrepancy. Although the SMF of high-redshift galaxies is still affected by significant errors, we show that future large-area surveys will substantially reduce them, making our method an effective tool to probe the massive end of the main sequence of
star-forming galaxies.},
urldate = {2018-01-10},
journal = {ArXiv e-prints},
author = {Davidzon, Iary and Ilbert, Olivier and Faisst, Andreas L. and Sparre, Martin and Capak, Peter L.},
month = dec,
year = {2017},
keywords = {Astrophysics - Astrophysics of Galaxies, Astrophysics - Cosmology and Nongalactic Astrophysics},
pages = {arXiv:1712.03959},
}The Impact of Environment on the Stellar Mass - Halo Mass Relation. Golden-Marx, J. B. & Miller, C. J. ArXiv e-prints, 1711:arXiv:1711.00481, November, 2017.
Paper abstract bibtex
Paper abstract bibtex A large variance exists in the amplitude of the Stellar Mass - Halo Mass (SMHM) relation for group and cluster-size halos. We show that the magnitude gap between the brightest central galaxy (BCG) and its second or fourth brightest neighbor accounts for a significant portion of this variance. We find that at fixed halo mass, galaxy clusters with a higher magnitude gap have a higher BCG stellar mass. This relationship is also observed in semi-analytic representations of low-redshift galaxy clusters in simulations. This SMHM-magnitude gap stratification likely results from BCG growth via hierarchical mergers and may link assembly of the halo with the growth of the BCG. Using a Bayesian model, we quantify the importance of the magnitude gap in the SMHM relation using a stretch factor, which we find to be significantly non-zero. The inclusion of the magnitude gap in the SMHM relation results in a large reduction in the inferred intrinsic scatter in the BCG stellar mass at fixed halo mass. We discuss the ramifications of this result in the context of galaxy formation models of centrals in group and cluster-sized halos.
@article{golden-marx_impact_2017,
title = {The {Impact} of {Environment} on the {Stellar} {Mass} - {Halo} {Mass} {Relation}},
volume = {1711},
url = {http://adsabs.harvard.edu/abs/2017arXiv171100481G},
abstract = {A large variance exists in the amplitude of the Stellar Mass - Halo Mass (SMHM) relation for group and cluster-size halos. We show that the magnitude gap between the brightest central galaxy (BCG) and its second or fourth brightest neighbor accounts for a significant portion of this variance. We find that at fixed halo mass, galaxy clusters with a higher magnitude gap have a higher BCG stellar mass. This relationship is also observed in semi-analytic representations of low-redshift galaxy clusters in simulations. This SMHM-magnitude gap stratification likely results from BCG growth via hierarchical mergers and may link assembly of the halo with the growth of the BCG. Using a Bayesian model, we quantify the importance of the magnitude gap in the SMHM relation using a stretch factor, which we find to be significantly non-zero. The inclusion of the magnitude gap in the SMHM relation results in a large reduction in the inferred intrinsic scatter in the BCG stellar mass at fixed halo mass. We discuss the ramifications of this result in the context of galaxy formation models of centrals in group and
cluster-sized halos.},
journal = {ArXiv e-prints},
author = {Golden-Marx, Jesse B. and Miller, Christopher J.},
month = nov,
year = {2017},
keywords = {Astrophysics - Astrophysics of Galaxies},
pages = {arXiv:1711.00481},
}The multiphase circumgalactic medium traced by low metal ions in EAGLE zoom simulations. Oppenheimer, B. D., Schaye, J., Crain, R. A., Werk, J. K., & Richings, A. J. ArXiv e-prints, 1709:arXiv:1709.07577, September, 2017.
Paper abstract bibtex
Paper abstract bibtex We explore the circumgalactic metal content traced by commonly observed low ion absorbers, including C II, Si II, Si III, Si IV, and Mg II. We use a set of cosmological hydrodynamical zoom simulations run with the EAGLE model and including a non-equilibrium ionization and cooling module that follows 136 ions. The simulations of z\textasciitilde0.2 L* (M_200=10\textasciicircum11.7-10\textasciicircum12.3 Msol) haloes hosting star-forming galaxies and group-sized (M_200=10\textasciicircum12.7-10\textasciicircum13.3 Msol) haloes hosting mainly passive galaxies reproduce key trends observed by the COS-Halos survey– low ion column densities show 1) little dependence on galaxy specific star formation rate, 2) a patchy covering fraction indicative of 10\textasciicircum4 K clouds with a small volume filling factor, and 3) a declining covering fraction as impact parameter increases from 20-160 kpc. Simulated Si II, Si III, Si IV, C II, and C III column densities show good agreement with observations, while Mg II is under-predicted. Low ions trace a significant metal reservoir, \textasciitilde10\textasciicircum8 Msol, residing primarily at 10-100 kpc from star-forming and passive central galaxies. These clouds tend to flow inwards and most will accrete onto the central galaxy within the next several Gyr, while a small fraction are entrained in strong outflows. A two-phase structure describes the inner CGM (\textless0.5 R_200) with low-ion metal clouds surrounded by a hot, ambient medium. This cool phase is separate from the O VI observed by COS-Halos, which arises from the outer CGM (\textgreater0.5 R_200) tracing virial temperature gas around L* galaxies. Physical parameters derived from standard photo-ionization modelling of observed column densities (e.g. aligned Si II/Si III absorbers) are validated against our simulations. Our simulations therefore support previous ionization models indicating that cloud covering factors decline while densities and pressures show little variation with increasing impact parameter.
@article{oppenheimer_multiphase_2017,
title = {The multiphase circumgalactic medium traced by low metal ions in {EAGLE} zoom simulations},
volume = {1709},
url = {http://adsabs.harvard.edu/abs/2017arXiv170907577O},
abstract = {We explore the circumgalactic metal content traced by commonly observed
low ion absorbers, including C II, Si II, Si III, Si IV, and Mg II. We
use a set of cosmological hydrodynamical zoom simulations run with the
EAGLE model and including a non-equilibrium ionization and cooling
module that follows 136 ions. The simulations of z{\textasciitilde}0.2 L*
(M\_200=10{\textasciicircum}11.7-10{\textasciicircum}12.3 Msol) haloes hosting star-forming galaxies and
group-sized (M\_200=10{\textasciicircum}12.7-10{\textasciicircum}13.3 Msol) haloes hosting mainly passive
galaxies reproduce key trends observed by the COS-Halos survey-- low ion
column densities show 1) little dependence on galaxy specific star
formation rate, 2) a patchy covering fraction indicative of 10{\textasciicircum}4 K
clouds with a small volume filling factor, and 3) a declining covering
fraction as impact parameter increases from 20-160 kpc. Simulated Si II,
Si III, Si IV, C II, and C III column densities show good agreement with
observations, while Mg II is under-predicted. Low ions trace a
significant metal reservoir, {\textasciitilde}10{\textasciicircum}8 Msol, residing primarily at 10-100
kpc from star-forming and passive central galaxies. These clouds tend to
flow inwards and most will accrete onto the central galaxy within the
next several Gyr, while a small fraction are entrained in strong
outflows. A two-phase structure describes the inner CGM ({\textless}0.5 R\_200)
with low-ion metal clouds surrounded by a hot, ambient medium. This cool
phase is separate from the O VI observed by COS-Halos, which arises from
the outer CGM ({\textgreater}0.5 R\_200) tracing virial temperature gas around L*
galaxies. Physical parameters derived from standard photo-ionization
modelling of observed column densities (e.g. aligned Si II/Si III
absorbers) are validated against our simulations. Our simulations
therefore support previous ionization models indicating that cloud
covering factors decline while densities and pressures show little
variation with increasing impact parameter.},
journal = {ArXiv e-prints},
author = {Oppenheimer, Benjamin D. and Schaye, Joop and Crain, Robert A. and Werk, Jessica K. and Richings, Alexander J.},
month = sep,
year = {2017},
keywords = {Astrophysics - Astrophysics of Galaxies},
pages = {arXiv:1709.07577},
}Enhancement of Galaxy Overdensity around Quasar Pairs at z\textless3.6 based on the Hyper Suprime-Cam Subaru Strategic Program Survey. Onoue, M., Kashikawa, N., Uchiyama, H., Akiyama, M., Harikane, Y., Imanishi, M., Komiyama, Y., Matsuoka, Y., Nagao, T., Nishizawa, A. J., Oguri, M., Ouchi, M., Tanaka, M., Toba, Y., & Toshikawa, J. arXiv:1704.06051 [astro-ph], April, 2017. arXiv: 1704.06051
Paper abstract bibtex
Paper abstract bibtex We investigate the galaxy overdensity around \textless2 pMpc-scale quasar pairs at high (z\textgreater3) and low (z\textasciitilde1) redshift based on the unprecedentedly wide and deep optical survey of the Hyper Suprime-Cam Subaru Strategic Program (HSC-SSP). Using the first-year survey data covering effectively \textasciitilde121 deg2 in full-color and depth, we find two luminous pairs at z\textasciitilde3.6 and 3.3 which reside in \${\textgreater}5 {\textbackslash}sigma\$ overdense regions of g-dropout galaxies. The projected separations of the two pairs are \$R_{\textbackslash}perp=\$1.75 and 1.04 pMpc, and their velocity offsets are \${\textbackslash}Delta V=692\$ and \$1448\$ km s\${\textasciicircum}\{-1\}\$, respectively. This is in clear contrast to the average quasar environments in the same redshift range as discussed in Uchiyama et al. (2017), and implies that the quasar activity of the two pairs is triggered via major mergers in proto-clusters, unlike the vast majority of isolated quasars in general fields that may turn on due to non-merger events such as bar and disk instabilities. At z\textasciitilde1, we find 37 pairs in the current HSC-Wide coverage with \$R_{\textbackslash}perp{\textless}2\$ pMpc and \${\textbackslash}Delta V{\textless}2300\$ km s\${\textasciicircum}\{-1\}\$ including four from Hennawi et al. (2006). The distribution of the peak overdensity significance within two arcminutes around the pairs has a long tail toward high density (\${\textgreater}4{\textbackslash}sigma\$) regions. Thanks to the large sample size, we find a statistical evidence that this excess is unique in the pair environments when compared to single quasar and randomly-selected galaxy environments. Moreover, there are nine small-scale pairs with \$R_{\textbackslash}perp{\textless}1\$ pMpc, two of which are found to reside in cluster fields. Our results demonstrate that quasar pairs at z\textasciitilde1-4 tend to occur in massive haloes, although perhaps not the most massive ones, and that they can be used to search for rare density peaks especially at high redshifts.
@article{onoue_enhancement_2017,
title = {Enhancement of {Galaxy} {Overdensity} around {Quasar} {Pairs} at z{\textless}3.6 based on the {Hyper} {Suprime}-{Cam} {Subaru} {Strategic} {Program} {Survey}},
url = {http://arxiv.org/abs/1704.06051},
abstract = {We investigate the galaxy overdensity around {\textless}2 pMpc-scale quasar pairs at high (z{\textgreater}3) and low (z{\textasciitilde}1) redshift based on the unprecedentedly wide and deep optical survey of the Hyper Suprime-Cam Subaru Strategic Program (HSC-SSP). Using the first-year survey data covering effectively {\textasciitilde}121 deg2 in full-color and depth, we find two luminous pairs at z{\textasciitilde}3.6 and 3.3 which reside in \${\textgreater}5 {\textbackslash}sigma\$ overdense regions of g-dropout galaxies. The projected separations of the two pairs are \$R\_{\textbackslash}perp=\$1.75 and 1.04 pMpc, and their velocity offsets are \${\textbackslash}Delta V=692\$ and \$1448\$ km s\${\textasciicircum}\{-1\}\$, respectively. This is in clear contrast to the average quasar environments in the same redshift range as discussed in Uchiyama et al. (2017), and implies that the quasar activity of the two pairs is triggered via major mergers in proto-clusters, unlike the vast majority of isolated quasars in general fields that may turn on due to non-merger events such as bar and disk instabilities. At z{\textasciitilde}1, we find 37 pairs in the current HSC-Wide coverage with \$R\_{\textbackslash}perp{\textless}2\$ pMpc and \${\textbackslash}Delta V{\textless}2300\$ km s\${\textasciicircum}\{-1\}\$ including four from Hennawi et al. (2006). The distribution of the peak overdensity significance within two arcminutes around the pairs has a long tail toward high density (\${\textgreater}4{\textbackslash}sigma\$) regions. Thanks to the large sample size, we find a statistical evidence that this excess is unique in the pair environments when compared to single quasar and randomly-selected galaxy environments. Moreover, there are nine small-scale pairs with \$R\_{\textbackslash}perp{\textless}1\$ pMpc, two of which are found to reside in cluster fields. Our results demonstrate that quasar pairs at z{\textasciitilde}1-4 tend to occur in massive haloes, although perhaps not the most massive ones, and that they can be used to search for rare density peaks especially at high redshifts.},
urldate = {2017-04-25},
journal = {arXiv:1704.06051 [astro-ph]},
author = {Onoue, Masafusa and Kashikawa, Nobunari and Uchiyama, Hisakazu and Akiyama, Masayuki and Harikane, Yuichi and Imanishi, Masatoshi and Komiyama, Yutaka and Matsuoka, Yoshiki and Nagao, Tohru and Nishizawa, Atsushi J. and Oguri, Masamune and Ouchi, Masami and Tanaka, Masayuki and Toba, Yoshiki and Toshikawa, Jun},
month = apr,
year = {2017},
note = {arXiv: 1704.06051},
keywords = {Astrophysics - Astrophysics of Galaxies, Astrophysics - Cosmology and Nongalactic Astrophysics},
}The MOSDEF survey: the prevalence and properties of galaxy-wide AGN-driven outflows at \$z{\textbackslash}sim 2\$. Leung, G. C. K., Coil, A., Azadi, M., Aird, J., Shapley, A., Kriek, M., Mobasher, B., Reddy, N., Siana, B., Freeman, W., Price, S., Sanders, R., & Shivaei, I. ArXiv e-prints, 1703:arXiv:1703.10255, March, 2017.
Paper abstract bibtex
Paper abstract bibtex Using observations from the first two years of the MOSFIRE Deep Evolution Field (MOSDEF) survey, we study 13 AGN-driven outflows detected from a sample of 67 X-ray, IR and/or optically selected AGN at \$z {\textbackslash}sim 2\$. The AGN in the sample have bolometric luminosities spanning \$10{\textasciicircum}\{44\}-10{\textasciicircum}\{46\} {\textbackslash}mathrm\{erg s{\textasciicircum}\{-1\}\}\$, including both quasars and more common, moderate-luminosity AGN. We detect signatures of blueshifted, ionized gas outflows in the \textbackslashhbeta , [OIII], \textbackslashhalpha and/or [NII] emission lines of 19\textbackslash% of the AGN, while only 1.8\textbackslash% of the MOSDEF galaxies have similar outflows detected. The outflow velocities range from 300 to 1000 km s\${\textasciicircum}\{-1\}\$. Eight of the 13 detected outflows are spatially extended on similar scales as the host galaxies, with spatial extents of 2.5 to 11.0 kpc along the MOSFIRE slits. Outflows are detected uniformly across the galaxy star-forming main sequence, showing little trend with the stellar mass or SFR of the host galaxy. Line ratio diagnostics in the BPT diagram indicate that the outflowing gas is photoionized by the AGN. We do not find evidence for positive AGN feedback, either in our relatively small MOSDEF sample or in a much larger sample from SDSS. Analysis of the mass and energy outflow rates in the MOSDEF AGN indicates that stellar feedback is likely insufficient to drive these outflows at \$z {\textbackslash}sim 2\$ and that they are very likely to be AGN-driven. The outflows have mass-loading factors of \${\textbackslash}sim 1-5\$, suggesting that they help regulate star formation in their host galaxies, though they may not be sufficient to fully quench it.
@article{leung_mosdef_2017,
title = {The {MOSDEF} survey: the prevalence and properties of galaxy-wide {AGN}-driven outflows at \$z{\textbackslash}sim 2\$},
volume = {1703},
shorttitle = {The {MOSDEF} survey},
url = {http://adsabs.harvard.edu/abs/2017arXiv170310255L},
abstract = {Using observations from the first two years of the MOSFIRE Deep
Evolution Field (MOSDEF) survey, we study 13 AGN-driven outflows
detected from a sample of 67 X-ray, IR and/or optically selected AGN at
\$z {\textbackslash}sim 2\$. The AGN in the sample have bolometric luminosities spanning
\$10{\textasciicircum}\{44\}-10{\textasciicircum}\{46\} {\textbackslash}mathrm\{erg s{\textasciicircum}\{-1\}\}\$, including both quasars and more
common, moderate-luminosity AGN. We detect signatures of blueshifted,
ionized gas outflows in the {\textbackslash}hbeta , [OIII], {\textbackslash}halpha and/or [NII]
emission lines of 19{\textbackslash}\% of the AGN, while only 1.8{\textbackslash}\% of the MOSDEF
galaxies have similar outflows detected. The outflow velocities range
from 300 to 1000 km s\${\textasciicircum}\{-1\}\$. Eight of the 13 detected outflows are
spatially extended on similar scales as the host galaxies, with spatial
extents of 2.5 to 11.0 kpc along the MOSFIRE slits. Outflows are
detected uniformly across the galaxy star-forming main sequence, showing
little trend with the stellar mass or SFR of the host galaxy. Line ratio
diagnostics in the BPT diagram indicate that the outflowing gas is
photoionized by the AGN. We do not find evidence for positive AGN
feedback, either in our relatively small MOSDEF sample or in a much
larger sample from SDSS. Analysis of the mass and energy outflow rates
in the MOSDEF AGN indicates that stellar feedback is likely insufficient
to drive these outflows at \$z {\textbackslash}sim 2\$ and that they are very likely to
be AGN-driven. The outflows have mass-loading factors of \${\textbackslash}sim 1-5\$,
suggesting that they help regulate star formation in their host
galaxies, though they may not be sufficient to fully quench it.},
urldate = {2017-04-05},
journal = {ArXiv e-prints},
author = {Leung, Gene C. K. and Coil, Alison and Azadi, Mojegan and Aird, James and Shapley, Alice and Kriek, Mariska and Mobasher, Bahram and Reddy, Naveen and Siana, Brian and Freeman, William and Price, Sedona and Sanders, Ryan and Shivaei, Irene},
month = mar,
year = {2017},
keywords = {Astrophysics - Astrophysics of Galaxies},
pages = {arXiv:1703.10255},
}EMERGE - An empirical model for the formation of galaxies since \$z{\textbackslash}sim10\$. Moster, B. P., Naab, T., & White, S. D. M. ArXiv e-prints, 1705:arXiv:1705.05373, May, 2017.
Paper abstract bibtex
Paper abstract bibtex We present EMERGE, an Empirical ModEl for the foRmation of GalaxiEs, describing the evolution of individual galaxies in large volumes from \$z{\textbackslash}sim10\$ to the present day. We assign a star formation rate to each dark matter halo based on its growth rate, which specifies how much baryonic material becomes available, and the instantaneous baryon conversion efficiency, which determines how efficiently this material is converted to stars, thereby capturing the baryonic physics. Satellites are quenched following the delayed-then-rapid model, and they are tidally disrupted once their subhalo has lost a significant fraction of its mass. The model is constrained with observed data extending out to high redshift. The empirical relations are very flexible, and the model complexity is increased only if required by the data, assessed by several model selection statistics. We find that for the same final halo mass galaxies can have very different star formation histories. Nevertheless, the average star formation and accretion rates are in good agreement with models following an abundance matching strategy. Galaxies that are quenched at \$z=0\$ typically have a higher peak star formation rate compared to their star-forming counterparts. The accretion of stars can dominate the total mass of massive galaxies, but is insignificant for low-mass systems, independent of star-formation activity. EMERGE predicts stellar-to-halo mass ratios for individual galaxies and introduces scatter self-consistently. We find that at fixed halo mass, passive galaxies have a higher stellar mass on average. The intra-cluster-mass in massive haloes can be up to 8 times larger than the mass of the central galaxy. Clustering for star-forming and quenched galaxies is in good agreement with observational constraints, indicating a realistic assignment of galaxies to haloes.
@article{moster_emerge_2017,
title = {{EMERGE} - {An} empirical model for the formation of galaxies since \$z{\textbackslash}sim10\$},
volume = {1705},
url = {http://adsabs.harvard.edu/abs/2017arXiv170505373M},
abstract = {We present EMERGE, an Empirical ModEl for the foRmation of GalaxiEs, describing the evolution of individual galaxies in large volumes from \$z{\textbackslash}sim10\$ to the present day. We assign a star formation rate to each dark matter halo based on its growth rate, which specifies how much baryonic material becomes available, and the instantaneous baryon conversion efficiency, which determines how efficiently this material is converted to stars, thereby capturing the baryonic physics. Satellites are quenched following the delayed-then-rapid model, and they are tidally disrupted once their subhalo has lost a significant fraction of its mass. The model is constrained with observed data extending out to high redshift. The empirical relations are very flexible, and the model complexity is increased only if required by the data, assessed by several model selection statistics. We find that for the same final halo mass galaxies can have very different star formation histories.
Nevertheless, the average star formation and accretion rates are in good agreement with models following an abundance matching strategy. Galaxies that are quenched at \$z=0\$ typically have a higher peak star formation rate compared to their star-forming counterparts. The accretion of stars can dominate the total mass of massive galaxies, but is insignificant for low-mass systems, independent of star-formation activity. EMERGE predicts stellar-to-halo mass ratios for individual galaxies and introduces scatter self-consistently. We find that at fixed halo mass, passive galaxies have a higher stellar mass on average. The
intra-cluster-mass in massive haloes can be up to 8 times larger than the mass of the central galaxy. Clustering for star-forming and quenched galaxies is in good agreement with observational constraints, indicating a realistic assignment of galaxies to haloes.},
urldate = {2017-05-25},
journal = {ArXiv e-prints},
author = {Moster, Benjamin P. and Naab, Thorsten and White, Simon D. M.},
month = may,
year = {2017},
keywords = {Astrophysics - Astrophysics of Galaxies},
pages = {arXiv:1705.05373},
}Merger-Induced Metallicity Dilution in Cosmological Galaxy Formation Simulations. Bustamante, S., Sparre, M., Springel, V., & Grand, R. J. J. arXiv:1712.03250 [astro-ph], December, 2017. arXiv: 1712.03250
Paper doi abstract bibtex
Paper doi abstract bibtex Observational studies have revealed that galaxy pairs tend to have lower gas-phase metallicity than isolated galaxies. This metallicity deficiency can be caused by inflows of low-metallicity gas due to the tidal forces and gravitational torques associated with galaxy mergers, diluting the metal content of the central region. In this work we demonstrate that such metallicity dilution occurs in state-of-the-art cosmological simulations of galaxy formation. We find that the dilution is typically 0.1 dex for major mergers, and is noticeable at projected separations smaller than \$40\$ kpc. For minor mergers the metallicity dilution is still present, even though the amplitude is significantly smaller. Consistent with previous analysis of observed galaxies we find that mergers are outliers from the \textbackslashemph\fundamental metallicity relation\, with deviations being larger than expected for a Gaussian distribution of residuals. Our large sample of mergers within full cosmological simulations also makes it possible to estimate how the star formation rate enhancement and gas consumption timescale behave as a function of the merger mass ratio. We confirm that strong starbursts are likely to occur in major mergers, but they can also arise in minor mergers if more than two galaxies are participating in the interaction, a scenario that has largely been ignored in previous work based on idealised isolated merger simulations.
@article{bustamante_merger-induced_2017,
title = {Merger-{Induced} {Metallicity} {Dilution} in {Cosmological} {Galaxy} {Formation} {Simulations}},
url = {http://arxiv.org/abs/1712.03250},
doi = {10.5281/zenodo.836631},
abstract = {Observational studies have revealed that galaxy pairs tend to have lower gas-phase metallicity than isolated galaxies. This metallicity deficiency can be caused by inflows of low-metallicity gas due to the tidal forces and gravitational torques associated with galaxy mergers, diluting the metal content of the central region. In this work we demonstrate that such metallicity dilution occurs in state-of-the-art cosmological simulations of galaxy formation. We find that the dilution is typically 0.1 dex for major mergers, and is noticeable at projected separations smaller than \$40\$ kpc. For minor mergers the metallicity dilution is still present, even though the amplitude is significantly smaller. Consistent with previous analysis of observed galaxies we find that mergers are outliers from the {\textbackslash}emph\{fundamental metallicity relation\}, with deviations being larger than expected for a Gaussian distribution of residuals. Our large sample of mergers within full cosmological simulations also makes it possible to estimate how the star formation rate enhancement and gas consumption timescale behave as a function of the merger mass ratio. We confirm that strong starbursts are likely to occur in major mergers, but they can also arise in minor mergers if more than two galaxies are participating in the interaction, a scenario that has largely been ignored in previous work based on idealised isolated merger simulations.},
urldate = {2018-01-10},
journal = {arXiv:1712.03250 [astro-ph]},
author = {Bustamante, Sebastian and Sparre, Martin and Springel, Volker and Grand, Robert J. J.},
month = dec,
year = {2017},
note = {arXiv: 1712.03250},
keywords = {Astrophysics - Astrophysics of Galaxies},
}A Radio-to-mm Census of Star-forming Galaxies in Protocluster 4C23.56 at Z = 2.5: Gas Mass and Its Fraction Revealed with ALMA. Lee, M. M., Tanaka, I., Kawabe, R., Kohno, K., Kodama, T., Kajisawa, M., Yun, M. S., Nakanishi, K., Iono, D., Tamura, Y., Hatsukade, B., Umehata, H., Saito, T., Izumi, T., Aretxaga, I., Tadaki, K., Zeballos, M., Ikarashi, S., Wilson, G. W., Hughes, D. H., & Ivison, R. J. The Astrophysical Journal, 842(1):55, June, 2017.
Paper doi abstract bibtex
Paper doi abstract bibtex We investigate gas contents of star-forming galaxies associated with protocluster 4C23.56 at z = 2.49 by using the redshifted CO (3-2) and 1.1 mm dust continuum with the Atacama Large Millimeter/submillimeter Array. The observations unveil seven CO detections out of 22 targeted Hα emitters (HAEs) and four out of 19 in 1.1 mm dust continuum. They have high stellar mass (\M\\textlessSUB\textgreater\textbackslashstar \textless/SUB\textgreater> 4× \10\\textlessSUP\textgreater10\textless/SUP\textgreater M \textlessSUB\textgreater☉\textless/SUB\textgreater) and exhibit a specific star-formation rate typical of main-sequence star-forming galaxies at z̃ 2.5. Different gas-mass estimators from CO (3-2) and 1.1 mm yield consistent values for simultaneous detections. The gas mass (\M\\textlessSUB\textgreater\gas\textless/SUB\textgreater\) and gas fraction (\f\\textlessSUB\textgreater\gas\textless/SUB\textgreater\) are comparable to those of field galaxies, with \M\\textlessSUB\textgreater\gas\textless/SUB\textgreater\=[0.3,1.8]× \10\\textlessSUP\textgreater11\textless/SUP\textgreater× (\α \\textlessSUB\textgreater\CO\textless/SUB\textgreater\/(4.36× A(Z))) \M\\textlessSUB\textgreater☉ \textless/SUB\textgreater, where \α \\textlessSUB\textgreater\CO\textless/SUB\textgreater\ is the CO-to-H\textlessSUB\textgreater2\textless/SUB\textgreater conversion factor and A(Z) is the additional correction factor for the metallicity dependence of \α \\textlessSUB\textgreater\CO\textless/SUB\textgreater\, and < \f\\textlessSUB\textgreater\gas\textless/SUB\textgreater\> =0.53+/- 0.07 from CO (3-2). Our measurements place a constraint on the cosmic gas density of high-z protoclusters, indicating that the protocluster is characterized by a gas density higher than that of the general fields by an order of magnitude. We found ρ (\H\\textlessSUB\textgreater2\textless/SUB\textgreater)̃ 5× \10\\textlessSUP\textgreater9\textless/SUP\textgreater \M\\textlessSUB\textgreater☉ \textless/SUB\textgreater \\Mpc\\\textlessSUP\textgreater-3\textless/SUP\textgreater with the CO(3-2) detections. The five ALMA CO detections occur in the region of highest galaxy surface density, where the density positively correlates with global star-forming efficiency (SFE) and stellar mass. Such correlations possibly indicate a critical role of the environment on early galaxy evolution at high-z protoclusters, though future observations are necessary for confirmation.
@article{lee_radio--mm_2017,
title = {A {Radio}-to-mm {Census} of {Star}-forming {Galaxies} in {Protocluster} {4C23}.56 at {Z} = 2.5: {Gas} {Mass} and {Its} {Fraction} {Revealed} with {ALMA}},
volume = {842},
shorttitle = {A {Radio}-to-mm {Census} of {Star}-forming {Galaxies} in {Protocluster} {4C23}.56 at {Z} = 2.5},
url = {https://ui.adsabs.harvard.edu/abs/2017ApJ...842...55L/abstract},
doi = {10.3847/1538-4357/aa74c2},
abstract = {We investigate gas contents of star-forming galaxies associated with protocluster 4C23.56 at z = 2.49 by using the redshifted CO (3-2) and 1.1 mm dust continuum with the Atacama Large Millimeter/submillimeter Array. The observations unveil seven CO detections out of 22 targeted Hα emitters (HAEs) and four out of 19 in 1.1 mm dust continuum. They have high stellar mass (\{M\}{\textless}SUB{\textgreater}{\textbackslash}star {\textless}/SUB{\textgreater}\> 4× \{10\}{\textless}SUP{\textgreater}10{\textless}/SUP{\textgreater} M {\textless}SUB{\textgreater}☉{\textless}/SUB{\textgreater}) and exhibit a specific star-formation rate typical of main-sequence star-forming galaxies at z̃ 2.5. Different gas-mass estimators from CO (3-2) and 1.1 mm yield consistent values for simultaneous detections. The gas mass (\{M\}{\textless}SUB{\textgreater}\{gas{\textless}/SUB{\textgreater}\}) and gas fraction (\{f\}{\textless}SUB{\textgreater}\{gas{\textless}/SUB{\textgreater}\}) are comparable to those of field galaxies, with \{M\}{\textless}SUB{\textgreater}\{gas{\textless}/SUB{\textgreater}\}=[0.3,1.8]× \{10\}{\textless}SUP{\textgreater}11{\textless}/SUP{\textgreater}× (\{α \}{\textless}SUB{\textgreater}\{CO{\textless}/SUB{\textgreater}\}/(4.36× A(Z))) \{M\}{\textless}SUB{\textgreater}☉ {\textless}/SUB{\textgreater}, where \{α \}{\textless}SUB{\textgreater}\{CO{\textless}/SUB{\textgreater}\} is the CO-to-H{\textless}SUB{\textgreater}2{\textless}/SUB{\textgreater} conversion factor and A(Z) is the additional correction factor for the metallicity dependence of \{α \}{\textless}SUB{\textgreater}\{CO{\textless}/SUB{\textgreater}\}, and \< \{f\}{\textless}SUB{\textgreater}\{gas{\textless}/SUB{\textgreater}\}\> =0.53+/- 0.07 from CO (3-2). Our measurements place a constraint on the cosmic gas density of high-z protoclusters, indicating that the protocluster is characterized by a gas density higher than that of the general fields by an order of magnitude. We found ρ (\{H\}{\textless}SUB{\textgreater}2{\textless}/SUB{\textgreater})̃ 5× \{10\}{\textless}SUP{\textgreater}9{\textless}/SUP{\textgreater} \{M\}{\textless}SUB{\textgreater}☉ {\textless}/SUB{\textgreater} \{\{Mpc\}\}{\textless}SUP{\textgreater}-3{\textless}/SUP{\textgreater} with the CO(3-2) detections. The five ALMA CO detections occur in the region of highest galaxy surface density, where the density positively correlates with global star-forming efficiency (SFE) and stellar mass. Such correlations possibly indicate a critical role of the environment on early galaxy evolution at high-z protoclusters, though future observations are necessary for confirmation.},
language = {en},
number = {1},
urldate = {2019-05-28},
journal = {The Astrophysical Journal},
author = {Lee, Minju M. and Tanaka, Ichi and Kawabe, Ryohei and Kohno, Kotaro and Kodama, Tadayuki and Kajisawa, Masaru and Yun, Min S. and Nakanishi, Kouichiro and Iono, Daisuke and Tamura, Yoichi and Hatsukade, Bunyo and Umehata, Hideki and Saito, Toshiki and Izumi, Takuma and Aretxaga, Itziar and Tadaki, Ken-ichi and Zeballos, Milagros and Ikarashi, Soh and Wilson, Grant W. and Hughes, David H. and Ivison, R. J.},
month = jun,
year = {2017},
keywords = {Astrophysics - Astrophysics of Galaxies},
pages = {55},
}Detection of a Substantial Molecular Gas Reservoir in a brightest cluster galaxy at z = 1.7. Webb, T., Lowenthal, J., Yun, M., Noble, A. G., Muzzin, A., Wilson, G., Yee, H. K. C., & Cybulski, R. ArXiv e-prints, 1706:arXiv:1706.01366, June, 2017.
Paper abstract bibtex
Paper abstract bibtex We report the detection of CO(2-1) emission coincident with the brightest cluster galaxy (BCG) of the high-redshift galaxy cluster SpARCS1049+56, with the Redshift Search Receiver (RSR) on the Large Millimetre Telescope (LMT). We confirm a spectroscopic redshift for the gas of z = 1.7091+/-0.0004, which is consistent with the systemic redshift of the cluster galaxies of z = 1.709. The line is well-fit by a single component Gaussian with a RSR resolution-corrected FWHM of 569+/-63 km/s. We see no evidence for multiple velocity components in the gas, as might be expected from the multiple image components seen in near-infrared imaging with the Hubble Space Telescope. We measure the integrated flux of the line to be 3.6+/-0.3 Jy km/s and, using alpha_CO = 0.8 Msun (K km s\textasciicircum-1 pc\textasciicircum2)\textasciicircum-1 we estimate a total molecular gas mass of 1.1+/-0.1x10\textasciicircum11 Msun and a M_H2/M_star \textasciitilde 0.4. This is the largest gas reservoir detected in a BCG above z \textgreater 1 to date. Given the infrared-estimated star formation rate of 860+/-130 Msun/yr, this corresponds to a gas depletion timescale of \textasciitilde0.1Gyr. We discuss several possible mechanisms for depositing such a large gas reservoir to the cluster center – e.g., a cooling flow, a major galaxy-galaxy merger or the stripping of gas from several galaxies – but conclude that these LMT data are not sufficient to differentiate between them.
@article{webb_detection_2017,
title = {Detection of a {Substantial} {Molecular} {Gas} {Reservoir} in a brightest cluster galaxy at z = 1.7},
volume = {1706},
url = {http://adsabs.harvard.edu/abs/2017arXiv170601366W},
abstract = {We report the detection of CO(2-1) emission coincident with the
brightest cluster galaxy (BCG) of the high-redshift galaxy cluster
SpARCS1049+56, with the Redshift Search Receiver (RSR) on the Large
Millimetre Telescope (LMT). We confirm a spectroscopic redshift for the
gas of z = 1.7091+/-0.0004, which is consistent with the systemic
redshift of the cluster galaxies of z = 1.709. The line is well-fit by a
single component Gaussian with a RSR resolution-corrected FWHM of
569+/-63 km/s. We see no evidence for multiple velocity components in
the gas, as might be expected from the multiple image components seen in
near-infrared imaging with the Hubble Space Telescope. We measure the
integrated flux of the line to be 3.6+/-0.3 Jy km/s and, using alpha\_CO
= 0.8 Msun (K km s{\textasciicircum}-1 pc{\textasciicircum}2){\textasciicircum}-1 we estimate a total molecular gas mass of
1.1+/-0.1x10{\textasciicircum}11 Msun and a M\_H2/M\_star {\textasciitilde} 0.4. This is the largest gas
reservoir detected in a BCG above z {\textgreater} 1 to date. Given the
infrared-estimated star formation rate of 860+/-130 Msun/yr, this
corresponds to a gas depletion timescale of {\textasciitilde}0.1Gyr. We discuss several
possible mechanisms for depositing such a large gas reservoir to the
cluster center -- e.g., a cooling flow, a major galaxy-galaxy merger or
the stripping of gas from several galaxies -- but conclude that these
LMT data are not sufficient to differentiate between them.},
journal = {ArXiv e-prints},
author = {Webb, Tracy and Lowenthal, James and Yun, Min and Noble, Allison G. and Muzzin, Adam and Wilson, Gillian and Yee, H. K. C. and Cybulski, Ryan},
month = jun,
year = {2017},
keywords = {Astrophysics - Astrophysics of Galaxies},
pages = {arXiv:1706.01366},
}Extent and structure of intervening absorbers from absorption lines redshifted on quasar emission lines. Bergeron, J. & Boisse, P. ArXiv e-prints, 1705:arXiv:1705.05131, May, 2017.
Paper abstract bibtex
Paper abstract bibtex We wish to study the extent and subparsec scale spatial structure of intervening quasar absorbers, mainly those involving neutral and molecular gas. We have selected quasar absorption systems with high spectral resolution and good S/N data, with some of their lines falling on quasar emission features. By investigating the consistency of absorption profiles seen for lines formed either against the quasar continuum source or on the much more extended emission line region (ELR), we can probe the extent and structure of the foreground absorber over the extent of the ELR (0.3-1 pc). The spatial covering analysis provides constraints on the transverse size of the absorber and thus is complementary to variability or photoionisation modelling studies. The methods we used to identify spatial covering or structure effects involve line profile fitting and curve of growth analysis.We have detected three absorbers with unambiguous non uniformity effects in neutral gas. For one extreme case, the FeI absorber at z_abs=0.45206 towards HE 0001-2340, we derive a coverage factor of the ELR of at most 0.10 and possibly very close to zero; this implies an absorber overall size no larger than 0.06 pc. For the z_abs=2.41837 CI absorber towards QSO J1439+1117, absorption is significantly stronger towards the ELR than towards the continuum source in several CI and CI* velocity components pointing to factors of about two spatial variations of their column densities and the presence of structures at the 100 au - 0.1 pc scale. The other systems with firm or possible effects can be described in terms of partial covering of the ELR, with coverage factors in the range 0.7 - 1. The overall results for cold, neutral absorbers imply a transverse extent of about five times or less the ELR size, which is consistent with other known constraints.
@article{bergeron_extent_2017,
title = {Extent and structure of intervening absorbers from absorption lines redshifted on quasar emission lines},
volume = {1705},
url = {http://adsabs.harvard.edu/abs/2017arXiv170505131B},
abstract = {We wish to study the extent and subparsec scale spatial structure of
intervening quasar absorbers, mainly those involving neutral and
molecular gas. We have selected quasar absorption systems with high
spectral resolution and good S/N data, with some of their lines falling
on quasar emission features. By investigating the consistency of
absorption profiles seen for lines formed either against the quasar
continuum source or on the much more extended emission line region
(ELR), we can probe the extent and structure of the foreground absorber
over the extent of the ELR (0.3-1 pc). The spatial covering analysis
provides constraints on the transverse size of the absorber and thus is
complementary to variability or photoionisation modelling studies. The
methods we used to identify spatial covering or structure effects
involve line profile fitting and curve of growth analysis.We have
detected three absorbers with unambiguous non uniformity effects in
neutral gas. For one extreme case, the FeI absorber at z\_abs=0.45206
towards HE 0001-2340, we derive a coverage factor of the ELR of at most
0.10 and possibly very close to zero; this implies an absorber overall
size no larger than 0.06 pc. For the z\_abs=2.41837 CI absorber towards
QSO J1439+1117, absorption is significantly stronger towards the ELR
than towards the continuum source in several CI and CI* velocity
components pointing to factors of about two spatial variations of their
column densities and the presence of structures at the 100 au - 0.1 pc
scale. The other systems with firm or possible effects can be described
in terms of partial covering of the ELR, with coverage factors in the
range 0.7 - 1. The overall results for cold, neutral absorbers imply a
transverse extent of about five times or less the ELR size, which is
consistent with other known constraints.},
urldate = {2017-05-18},
journal = {ArXiv e-prints},
author = {Bergeron, Jacqueline and Boisse, Patrick},
month = may,
year = {2017},
keywords = {Astrophysics - Astrophysics of Galaxies, Astrophysics - Cosmology and Nongalactic Astrophysics},
pages = {arXiv:1705.05131},
}Very compact millimeter sizes for composite star-forming/AGN submillimeter galaxies. Ikarashi, S., Caputi, K., Ohta, K., Ivison, R. J., Lagos, C. D. P., Bisigello, L., Hatsukade, B., Aretxaga, I., Dunlop, J. S., Hughes, D. H., Iono, D., Izumi, T., Kashikawa, N., Koyama, Y., Kawabe, R., Kohno, K., Motohara, K., Nakanishi, K., Tamura, Y., Umehata, H., Wilson, G. W., Yabe, K., & Yun, M. S. ArXiv e-prints, 1710:arXiv:1710.09021, October, 2017.
Paper abstract bibtex
Paper abstract bibtex We report the study of far-IR sizes of submillimeter galaxies (SMGs) in relation to their dust-obscured star formation rate (SFR) and active galactic nuclei (AGN) presence, determined using mid-IR photometry. We determined the millimeter-wave (\${\textbackslash}lambda_\{{\textbackslash}rm obs\}=1100 {\textbackslash}mu\$m) sizes of 69 ALMA-identified SMGs, selected with \${\textbackslash}geq10\$\${\textbackslash}sigma\$ confidence on ALMA images (\$F_\{{\textbackslash}rm 1100 {\textbackslash}mu m\}=1.7\$–7.4 mJy). We found that all the SMGs are located above an avoidance region in the millimeter size-flux plane, as expected by the Eddington limit for star formation. In order to understand what drives the different millimeter-wave sizes in SMGs, we investigated the relation between millimeter-wave size and AGN fraction for 25 of our SMGs at \$z=1\$–3. We found that the SMGs for which the mid-IR emission is dominated by star formation or AGN have extended millimeter-sizes, with respective median \$R_\{{\textbackslash}rm c,e\} = 1.6{\textasciicircum}\{+0.34\}_\{-0.21\}\$ and 1.5\${\textasciicircum}\{+0.93\}_\{-0.24\}\$ kpc. Instead, the SMGs for which the mid-IR emission corresponds to star-forming/AGN composites have more compact millimeter-wave sizes, with median \$R_\{p̌hantom{\}}{\textbackslash}rm c,ep̌hantom{\{}\}=1.0{\textasciicircum}\{+0.20\}_\{-0.20\}\$ kpc. The relation between millimeter-wave size and AGN fraction suggests that this size may be related to the evolutionary stage of the SMG. The very compact sizes for composite star-forming/AGN systems could be explained by supermassive black holes growing rapidly during the SMG coalescing, star-formation phase.
@article{ikarashi_very_2017,
title = {Very compact millimeter sizes for composite star-forming/{AGN} submillimeter galaxies},
volume = {1710},
url = {http://adsabs.harvard.edu/abs/2017arXiv171009021I},
abstract = {We report the study of far-IR sizes of submillimeter galaxies (SMGs) in
relation to their dust-obscured star formation rate (SFR) and active
galactic nuclei (AGN) presence, determined using mid-IR photometry. We
determined the millimeter-wave (\${\textbackslash}lambda\_\{{\textbackslash}rm obs\}=1100 {\textbackslash}mu\$m) sizes of
69 ALMA-identified SMGs, selected with \${\textbackslash}geq10\$\${\textbackslash}sigma\$ confidence on
ALMA images (\$F\_\{{\textbackslash}rm 1100 {\textbackslash}mu m\}=1.7\$--7.4 mJy). We found that all the
SMGs are located above an avoidance region in the millimeter size-flux
plane, as expected by the Eddington limit for star formation. In order
to understand what drives the different millimeter-wave sizes in SMGs,
we investigated the relation between millimeter-wave size and AGN
fraction for 25 of our SMGs at \$z=1\$--3. We found that the SMGs for
which the mid-IR emission is dominated by star formation or AGN have
extended millimeter-sizes, with respective median \$R\_\{{\textbackslash}rm c,e\} =
1.6{\textasciicircum}\{+0.34\}\_\{-0.21\}\$ and 1.5\${\textasciicircum}\{+0.93\}\_\{-0.24\}\$ kpc. Instead, the SMGs
for which the mid-IR emission corresponds to star-forming/AGN composites
have more compact millimeter-wave sizes, with median \$R\_\{\vphantom{\}}{\textbackslash}rm
c,e\vphantom{\{}\}=1.0{\textasciicircum}\{+0.20\}\_\{-0.20\}\$ kpc. The relation between millimeter-wave size
and AGN fraction suggests that this size may be related to the
evolutionary stage of the SMG. The very compact sizes for composite
star-forming/AGN systems could be explained by supermassive black holes
growing rapidly during the SMG coalescing, star-formation phase.},
journal = {ArXiv e-prints},
author = {Ikarashi, Soh and Caputi, Karina and Ohta, Kouji and Ivison, R. J. and Lagos, Claudia D. P. and Bisigello, Laura and Hatsukade, Bunyo and Aretxaga, Itziar and Dunlop, James S. and Hughes, David H. and Iono, Daisuke and Izumi, Takuma and Kashikawa, Nobunari and Koyama, Yusei and Kawabe, Ryohei and Kohno, Kotaro and Motohara, Kentaro and Nakanishi, Kouichiro and Tamura, Yoichi and Umehata, Hideki and Wilson, Grant W. and Yabe, Kiyoto and Yun, Min S.},
month = oct,
year = {2017},
keywords = {Astrophysics - Astrophysics of Galaxies},
pages = {arXiv:1710.09021},
}2016 (11)
Black Hole Kicks as New Gravitational Wave Observables. Gerosa, D. & Moore, C. J. Physical Review Letters, 117(1):011101, July, 2016.
doi bibtex
doi bibtex
@article{2016PhRvL.117a1101G,
adsnote = {Provided by the SAO/NASA Astrophysics Data System},
adsurl = {https://ui.adsabs.harvard.edu/abs/2016PhRvL.117a1101G},
archiveprefix = {arXiv},
author = {{Gerosa}, Davide and {Moore}, Christopher J.},
doi = {10.1103/PhysRevLett.117.011101},
eid = {011101},
eprint = {1606.04226},
journal = {Physical Review Letters},
keywords = {General Relativity and Quantum Cosmology, Astrophysics - Cosmology and Nongalactic Astrophysics, Astrophysics - Astrophysics of Galaxies, Astrophysics - High Energy Astrophysical Phenomena},
month = jul,
number = {1},
pages = {011101},
primaryclass = {gr-qc},
title = {{Black Hole Kicks as New Gravitational Wave Observables}},
volume = {117},
year = 2016,
bdsk-url-1 = {https://doi.org/10.1103/PhysRevLett.117.011101}}The spectral evolution of the first Galaxies. III. Simulated James Webb Space Telescope spectra of reionization-epoch galaxies with Lyman continuum leakage. Zackrisson, E., Binggeli, C., Finlator, K., Gnedin, N. Y., Paardekooper, J., Shimizu, I., Inoue, A. K., Jensen, H., Micheva, G., Khochfar, S., & Vecchia, C. D. arXiv:1608.08217 [astro-ph], August, 2016. arXiv: 1608.08217
Paper abstract bibtex
Paper abstract bibtex Using four different suites of cosmological simulations, we generate synthetic spectra for galaxies with different Lyman continuum escape fractions (fesc) at redshifts z=7-9, in the rest-frame wavelength range relevant for the James Webb Space Telescope (JWST) NIRSpec instrument. By investigating the effects of realistic star formation histories and metallicity distributions on the EW(Hb)-beta diagram (previously proposed as a tool for identifying galaxies with very high fesc), we find that the neither of these effects are likely to jeopardize the identification of galaxies with extreme Lyman continuum leakage. Based on our models, we expect essentially all z=7-9 galaxies that exhibit rest-frame EW(Hb)\textless 30 \\textbackslashAA\ to have fesc\textgreater0.5. Incorrect assumptions concerning the ionizing fluxes of stellar populations or the dust properties of z\textgreater6 galaxies can in principle bias the selection, but substantial model deficiencies of this type will at the same time reveal themselves as an offset between the observed and simulated distribution of z\textgreater6 galaxies in the EW(Hb)-beta diagram. Such offsets would thereby allow JWST/NIRSpec measurements of these observables to serve as input for further model refinement.
@article{zackrisson_spectral_2016,
title = {The spectral evolution of the first {Galaxies}. {III}. {Simulated} {James} {Webb} {Space} {Telescope} spectra of reionization-epoch galaxies with {Lyman} continuum leakage},
url = {http://arxiv.org/abs/1608.08217},
abstract = {Using four different suites of cosmological simulations, we generate synthetic spectra for galaxies with different Lyman continuum escape fractions (fesc) at redshifts z=7-9, in the rest-frame wavelength range relevant for the James Webb Space Telescope (JWST) NIRSpec instrument. By investigating the effects of realistic star formation histories and metallicity distributions on the EW(Hb)-beta diagram (previously proposed as a tool for identifying galaxies with very high fesc), we find that the neither of these effects are likely to jeopardize the identification of galaxies with extreme Lyman continuum leakage. Based on our models, we expect essentially all z=7-9 galaxies that exhibit rest-frame EW(Hb){\textless} 30 \{{\textbackslash}AA\} to have fesc{\textgreater}0.5. Incorrect assumptions concerning the ionizing fluxes of stellar populations or the dust properties of z{\textgreater}6 galaxies can in principle bias the selection, but substantial model deficiencies of this type will at the same time reveal themselves as an offset between the observed and simulated distribution of z{\textgreater}6 galaxies in the EW(Hb)-beta diagram. Such offsets would thereby allow JWST/NIRSpec measurements of these observables to serve as input for further model refinement.},
urldate = {2016-09-27},
journal = {arXiv:1608.08217 [astro-ph]},
author = {Zackrisson, E. and Binggeli, C. and Finlator, K. and Gnedin, N. Y. and Paardekooper, J.-P. and Shimizu, I. and Inoue, A. K. and Jensen, H. and Micheva, G. and Khochfar, S. and Vecchia, C. Dalla},
month = aug,
year = {2016},
note = {arXiv: 1608.08217},
keywords = {Astrophysics - Astrophysics of Galaxies, Astrophysics - Cosmology and Nongalactic Astrophysics},
}The Column Density Distribution of the Low-Redshift Lyman-Alpha Forest in Illustris. Gurvich, A., Burkhart, B., & Bird, S. arXiv:1608.03293 [astro-ph], August, 2016. arXiv: 1608.03293
Paper abstract bibtex
Paper abstract bibtex We investigate the low-redshift Lyman-alpha forest column density distribution in the Illustris simulation. We show that Illustris reproduces observations extremely well in the column density range 10\textasciicircum12.5-10\textasciicircum14.5 cm\textasciicircum-2, relevant for the "photon underproduction crisis." We attribute this to the inclusion of AGN feedback, which changes the gas distribution so as to mimic the effect of extra photons, as well as the use of the Faucher-Giguere (2009) ultra-violet background, which is more ionizing at z=0.1 than the Haardt & Madau (2012) background previously considered. We show that the difference between simulations run with smoothed particle hydrodynamics and simulations using a moving mesh is small in this column density range. We further consider the effect of supernova feedback, Voigt profile fitting and finite resolution, all of which we show to be small. Finally, we identify a discrepancy between our simulations and observations at column densities 10\textasciicircum14-10\textasciicircum16 cm\textasciicircum-2, where Illustris produces too few absorbers, which suggests the AGN feedback model in cosmological simulations should be further refined. However the "photon underproduction crisis," can be resolved by including AGN feedback and standard ionizing background models.
@article{gurvich_column_2016,
title = {The {Column} {Density} {Distribution} of the {Low}-{Redshift} {Lyman}-{Alpha} {Forest} in {Illustris}},
url = {http://arxiv.org/abs/1608.03293},
abstract = {We investigate the low-redshift Lyman-alpha forest column density distribution in the Illustris simulation. We show that Illustris reproduces observations extremely well in the column density range 10{\textasciicircum}12.5-10{\textasciicircum}14.5 cm{\textasciicircum}-2, relevant for the "photon underproduction crisis." We attribute this to the inclusion of AGN feedback, which changes the gas distribution so as to mimic the effect of extra photons, as well as the use of the Faucher-Giguere (2009) ultra-violet background, which is more ionizing at z=0.1 than the Haardt \& Madau (2012) background previously considered. We show that the difference between simulations run with smoothed particle hydrodynamics and simulations using a moving mesh is small in this column density range. We further consider the effect of supernova feedback, Voigt profile fitting and finite resolution, all of which we show to be small. Finally, we identify a discrepancy between our simulations and observations at column densities 10{\textasciicircum}14-10{\textasciicircum}16 cm{\textasciicircum}-2, where Illustris produces too few absorbers, which suggests the AGN feedback model in cosmological simulations should be further refined. However the "photon underproduction crisis," can be resolved by including AGN feedback and standard ionizing background models.},
urldate = {2016-10-25},
journal = {arXiv:1608.03293 [astro-ph]},
author = {Gurvich, Alex and Burkhart, Blakesley and Bird, Simeon},
month = aug,
year = {2016},
note = {arXiv: 1608.03293},
keywords = {Astrophysics - Astrophysics of Galaxies, Astrophysics - Cosmology and Nongalactic Astrophysics},
}Supermassive black holes in the EAGLE Universe. Revealing the observables of their growth. Rosas-Guevara, Y., Bower, R. G., Schaye, J., McAlpine, S., Dalla-Vecchia, C., Frenk, C. S., Schaller, M., & Theuns, T. Monthly Notices of the Royal Astronomical Society, 462(1):190–205, October, 2016. arXiv: 1604.00020
Paper doi abstract bibtex
Paper doi abstract bibtex We investigate the evolution of supermassive black holes in the `Evolution and Assembly of GaLaxies and their Environments' (EAGLE) cosmological hydrodynamic simulations. The largest of the EAGLE volumes covers a \$(100 {\textbackslash},{\textbackslash}rm cMpc){\textasciicircum}3\$ and includes state-of-the-art physical models for star formation and black hole growth that depend only on local gas properties. We focus on the black hole mass function, Eddington ratio distribution and the implied duty cycle of nuclear activity. The simulation is broadly consistent with observational constraints on these quantities. In order to make a more direct comparison with observational data, we calculate the soft and hard X-ray luminosity functions of the active galactic nuclei (AGN). Between redshifts \$0\$ and \$1\$, the simulation is in agreement with data. At higher redshifts, the simulation tends to underpredict the luminosities of the brightest observed AGN. This may be due to the limited volume of the simulation, or a fundamental deficiency of the underlying model. It seems unlikely that additional unresolved variability can account for this difference. The simulation shows a similar `downsizing' of the AGN population as seen in observational surveys.
@article{rosas-guevara_supermassive_2016,
title = {Supermassive black holes in the {EAGLE} {Universe}. {Revealing} the observables of their growth},
volume = {462},
issn = {0035-8711, 1365-2966},
url = {http://arxiv.org/abs/1604.00020},
doi = {10.1093/mnras/stw1679},
abstract = {We investigate the evolution of supermassive black holes in the `Evolution and Assembly of GaLaxies and their Environments' (EAGLE) cosmological hydrodynamic simulations. The largest of the EAGLE volumes covers a \$(100 {\textbackslash},{\textbackslash}rm cMpc){\textasciicircum}3\$ and includes state-of-the-art physical models for star formation and black hole growth that depend only on local gas properties. We focus on the black hole mass function, Eddington ratio distribution and the implied duty cycle of nuclear activity. The simulation is broadly consistent with observational constraints on these quantities. In order to make a more direct comparison with observational data, we calculate the soft and hard X-ray luminosity functions of the active galactic nuclei (AGN). Between redshifts \$0\$ and \$1\$, the simulation is in agreement with data. At higher redshifts, the simulation tends to underpredict the luminosities of the brightest observed AGN. This may be due to the limited volume of the simulation, or a fundamental deficiency of the underlying model. It seems unlikely that additional unresolved variability can account for this difference. The simulation shows a similar `downsizing' of the AGN population as seen in observational surveys.},
number = {1},
urldate = {2017-12-07},
journal = {Monthly Notices of the Royal Astronomical Society},
author = {Rosas-Guevara, Yetli and Bower, Richard G. and Schaye, Joop and McAlpine, Stuart and Dalla-Vecchia, Claudio and Frenk, Carlos S. and Schaller, Matthieu and Theuns, Tom},
month = oct,
year = {2016},
note = {arXiv: 1604.00020},
keywords = {Astrophysics - Astrophysics of Galaxies},
pages = {190--205},
}Lyman Alpha Signatures from Direct Collapse Black Holes. Dijkstra, M., Gronke, M., & Sobral, D. The Astrophysical Journal, 823(2):74, May, 2016. arXiv: 1602.07695
Paper doi abstract bibtex
Paper doi abstract bibtex `Direct collapse black holes' (DCBHs) provide possible seeds for supermassive black holes that exist at redshifts as high as z\textasciitilde7. We study Lyman Alpha (Lya) radiative transfer through simplified representations of the DCBH-scenario. We find that gravitational heating of the collapsing cloud gives rise to a Lya cooling luminosity of up to \textasciitilde 1e38(M_gas/1e6 Msun)\textasciicircum2 erg/s. The Lya production rate can be significantly larger during the final stages of collapse, but collisional deexcitation efficiently suppresses the emerging Lya flux. Photoionization by a central source boosts the Lya luminosity to L\textasciitilde1e43(M_BH/1e6 M_sun) erg/s during specific evolutionary stages of the cloud, where M_BH denotes the mass of the black hole powering this source. We predict that the width and velocity off-set of the Lya spectral line range from a few tens to few thousands km/s, depending sensitively on the evolutionary state of the cloud. We also compare our predictions to observations of CR7 (Sobral et al. 2015), a luminous Lya emitter at z\textasciitilde7, which is potentially associated with a DCBH. If CR7 is powered by a black hole, then its Lya flux alone requires that M_BH\textgreater 1e7 M_sun, which exceeds the mass of DCBHs when they first form. The observed width of the Lya spectrum favors the presence of only a low column density of hydrogen, log [N_HI/cm\textasciicircum-2]\textasciitilde19-20. The shape of the Lya spectrum indicates that this gas is outflowing. These requirements imply that if CR7 harbors a DCBH, then the physical conditions that enabled its formation have been mostly erased, which is in agreement with theoretical expectations.
@article{dijkstra_lyman_2016,
title = {Lyman {Alpha} {Signatures} from {Direct} {Collapse} {Black} {Holes}},
volume = {823},
issn = {1538-4357},
url = {http://arxiv.org/abs/1602.07695},
doi = {10.3847/0004-637X/823/2/74},
abstract = {`Direct collapse black holes' (DCBHs) provide possible seeds for supermassive black holes that exist at redshifts as high as z{\textasciitilde}7. We study Lyman Alpha (Lya) radiative transfer through simplified representations of the DCBH-scenario. We find that gravitational heating of the collapsing cloud gives rise to a Lya cooling luminosity of up to {\textasciitilde} 1e38(M\_gas/1e6 Msun){\textasciicircum}2 erg/s. The Lya production rate can be significantly larger during the final stages of collapse, but collisional deexcitation efficiently suppresses the emerging Lya flux. Photoionization by a central source boosts the Lya luminosity to L{\textasciitilde}1e43(M\_BH/1e6 M\_sun) erg/s during specific evolutionary stages of the cloud, where M\_BH denotes the mass of the black hole powering this source. We predict that the width and velocity off-set of the Lya spectral line range from a few tens to few thousands km/s, depending sensitively on the evolutionary state of the cloud. We also compare our predictions to observations of CR7 (Sobral et al. 2015), a luminous Lya emitter at z{\textasciitilde}7, which is potentially associated with a DCBH. If CR7 is powered by a black hole, then its Lya flux alone requires that M\_BH{\textgreater} 1e7 M\_sun, which exceeds the mass of DCBHs when they first form. The observed width of the Lya spectrum favors the presence of only a low column density of hydrogen, log [N\_HI/cm{\textasciicircum}-2]{\textasciitilde}19-20. The shape of the Lya spectrum indicates that this gas is outflowing. These requirements imply that if CR7 harbors a DCBH, then the physical conditions that enabled its formation have been mostly erased, which is in agreement with theoretical expectations.},
number = {2},
urldate = {2016-07-13},
journal = {The Astrophysical Journal},
author = {Dijkstra, Mark and Gronke, Max and Sobral, David},
month = may,
year = {2016},
note = {arXiv: 1602.07695},
keywords = {Astrophysics - Astrophysics of Galaxies, Astrophysics - Cosmology and Nongalactic Astrophysics},
pages = {74},
}The origin of the enhanced metallicity of satellite galaxies. Bahe, Y. M., Schaye, J., Crain, R. A., McCarthy, I. G., Bower, R. G., Theuns, T., McGee, S. L., & Trayford, J. W. arXiv:1609.03379 [astro-ph], September, 2016. arXiv: 1609.03379
Paper abstract bibtex
Paper abstract bibtex Observations of galaxies in the local Universe have shown that both the ionized gas and the stars of satellites are more metal-rich than of equally massive centrals. To gain insight into the connection between this metallicity enhancement and other differences between centrals and satellites, such as their star formation rates, gas content, and growth history, we study the metallicities of \textgreater3600 galaxies with M_star \textgreater 10\textasciicircum10 M_sun in the cosmological hydrodynamical EAGLE 100 Mpc `Reference' simulation, including \textasciitilde1500 in the vicinity of galaxy groups and clusters (M_200 \textgreater= 10\textasciicircum13 M_sun). The simulation predicts excess gas and stellar metallicities in satellites consistent with observations, except for stellar metallicities at M_star \textless\textasciitilde 10\textasciicircum10.2 M_sun where the predicted excess is smaller than observed. The exact magnitude of the effect depends on galaxy selection, aperture, and on whether the metallicity is weighted by stellar mass or luminosity. The stellar metallicity excess in clusters is also sensitive to the efficiency scaling of star formation feedback. We identify stripping of low-metallicity gas from the galaxy outskirts, as well as suppression of metal-poor inflows towards the galaxy centre, as key drivers of the enhancement of gas metallicity. Stellar metallicities in satellites are higher than in the field as a direct consequence of the more metal-rich star forming gas, whereas stripping of stars and suppressed stellar mass growth, as well as differences in accreted vs. in-situ star formation between satellites and the field, are of secondary importance.
@article{bahe_origin_2016,
title = {The origin of the enhanced metallicity of satellite galaxies},
url = {http://arxiv.org/abs/1609.03379},
abstract = {Observations of galaxies in the local Universe have shown that both the ionized gas and the stars of satellites are more metal-rich than of equally massive centrals. To gain insight into the connection between this metallicity enhancement and other differences between centrals and satellites, such as their star formation rates, gas content, and growth history, we study the metallicities of {\textgreater}3600 galaxies with M\_star {\textgreater} 10{\textasciicircum}10 M\_sun in the cosmological hydrodynamical EAGLE 100 Mpc `Reference' simulation, including {\textasciitilde}1500 in the vicinity of galaxy groups and clusters (M\_200 {\textgreater}= 10{\textasciicircum}13 M\_sun). The simulation predicts excess gas and stellar metallicities in satellites consistent with observations, except for stellar metallicities at M\_star {\textless}{\textasciitilde} 10{\textasciicircum}10.2 M\_sun where the predicted excess is smaller than observed. The exact magnitude of the effect depends on galaxy selection, aperture, and on whether the metallicity is weighted by stellar mass or luminosity. The stellar metallicity excess in clusters is also sensitive to the efficiency scaling of star formation feedback. We identify stripping of low-metallicity gas from the galaxy outskirts, as well as suppression of metal-poor inflows towards the galaxy centre, as key drivers of the enhancement of gas metallicity. Stellar metallicities in satellites are higher than in the field as a direct consequence of the more metal-rich star forming gas, whereas stripping of stars and suppressed stellar mass growth, as well as differences in accreted vs. in-situ star formation between satellites and the field, are of secondary importance.},
urldate = {2016-09-28},
journal = {arXiv:1609.03379 [astro-ph]},
author = {Bahe, Yannick M. and Schaye, Joop and Crain, Robert A. and McCarthy, Ian G. and Bower, Richard G. and Theuns, Tom and McGee, Sean L. and Trayford, James W.},
month = sep,
year = {2016},
note = {arXiv: 1609.03379},
keywords = {Astrophysics - Astrophysics of Galaxies},
}MUFASA: Galaxy Formation Simulations With Meshless Hydrodynamics. Davé, R., Thompson, R. J., & Hopkins, P. F. Monthly Notices of the Royal Astronomical Society, 462(3):3265–3284, November, 2016. arXiv: 1604.01418
Paper doi abstract bibtex
Paper doi abstract bibtex We present the MUFASA suite of cosmological hydrodynamic simulations, which employs the GIZMO meshless finite mass (MFM) code including H2-based star formation, nine-element chemical evolution, two-phase kinetic outflows following scalings from the Feedback in Realistic Environments zoom simulations, and evolving halo mass-based quenching. Our fiducial (50 Mpc/h)\textasciicircum3 volume is evolved to z=0 with a quarter billion particles, The predicted galaxy stellar mass functions (GSMF) reproduce observations from z=4-0 to \textless1.2sigma in cosmic variance, providing an unprecedented match to this key diagnostic. The cosmic star formation history and stellar mass growth show general agreement with data, with a strong archaeological downsizing trend such that dwarf galaxies form the majority of their stars after z\textasciitilde1. We run 25 Mpc/h and 12.5 Mpc/h volumes to z=2 with identical feedback prescriptions, the latter resolving all hydrogen-cooling halos, and the three runs display fair resolution convergence. The specific star formation rates broadly agree with data at z=0, but are underpredicted at z\textasciitilde2 by a factor of three, re-emphasizing a longstanding puzzle in galaxy evolution models. We compare runs using MFM and two flavours of Smoothed Particle Hydrodynamics, and show that the GSMF is sensitive to hydrodynamics methodology at the \textasciitildex2 level, which is sub-dominant to choices for parameterising feedback.
@article{dave_mufasa_2016,
title = {{MUFASA}: {Galaxy} {Formation} {Simulations} {With} {Meshless} {Hydrodynamics}},
volume = {462},
issn = {0035-8711, 1365-2966},
shorttitle = {{MUFASA}},
url = {http://arxiv.org/abs/1604.01418},
doi = {10.1093/mnras/stw1862},
abstract = {We present the MUFASA suite of cosmological hydrodynamic simulations, which employs the GIZMO meshless finite mass (MFM) code including H2-based star formation, nine-element chemical evolution, two-phase kinetic outflows following scalings from the Feedback in Realistic Environments zoom simulations, and evolving halo mass-based quenching. Our fiducial (50 Mpc/h){\textasciicircum}3 volume is evolved to z=0 with a quarter billion particles, The predicted galaxy stellar mass functions (GSMF) reproduce observations from z=4-0 to {\textless}1.2sigma in cosmic variance, providing an unprecedented match to this key diagnostic. The cosmic star formation history and stellar mass growth show general agreement with data, with a strong archaeological downsizing trend such that dwarf galaxies form the majority of their stars after z{\textasciitilde}1. We run 25 Mpc/h and 12.5 Mpc/h volumes to z=2 with identical feedback prescriptions, the latter resolving all hydrogen-cooling halos, and the three runs display fair resolution convergence. The specific star formation rates broadly agree with data at z=0, but are underpredicted at z{\textasciitilde}2 by a factor of three, re-emphasizing a longstanding puzzle in galaxy evolution models. We compare runs using MFM and two flavours of Smoothed Particle Hydrodynamics, and show that the GSMF is sensitive to hydrodynamics methodology at the {\textasciitilde}x2 level, which is sub-dominant to choices for parameterising feedback.},
number = {3},
journal = {Monthly Notices of the Royal Astronomical Society},
author = {Davé, Romeel and Thompson, Robert J. and Hopkins, Philip F.},
month = nov,
year = {2016},
note = {arXiv: 1604.01418},
keywords = {Astrophysics - Astrophysics of Galaxies},
pages = {3265--3284},
}The red sequence at birth in the galaxy cluster ClJ1449+0856 at z=2. Strazzullo, V., Daddi, E., Gobat, R., Valentino, F., Pannella, M., Dickinson, M., Renzini, A., Brammer, G., Onodera, M., Finoguenov, A., Cimatti, A., Carollo, C. M., & Arimoto, N. The Astrophysical Journal, 833(2):L20, December, 2016. arXiv: 1611.07976
Paper doi abstract bibtex
Paper doi abstract bibtex We use HST/WFC3 imaging to study the red population in the IR-selected, X-ray detected, low-mass cluster Cl J1449+0856 at z=2, one of the few bona-fide established clusters discovered at this redshift, and likely a typical progenitor of an average massive cluster today. This study explores the presence and significance of an early red sequence in the core of this structure, investigating the nature of red sequence galaxies, highlighting environmental effects on cluster galaxy populations at high redshift, and at the same time underlining similarities and differences with other distant dense environments. Our results suggest that the red population in the core of Cl J1449+0856 is made of a mixture of quiescent and dusty star-forming galaxies, with a seedling of the future red sequence already growing in the very central cluster region, and already characterising the inner cluster core with respect to lower density environments. On the other hand, the color-magnitude diagram of this cluster is definitely different from that of lower-redshift (z\textless1) clusters, as well as of some rare particularly evolved massive clusters at similar redshift, and it is suggestive of a transition phase between active star formation and passive evolution occurring in the proto-cluster and established lower-redshift cluster regimes.
@article{strazzullo_red_2016,
title = {The red sequence at birth in the galaxy cluster {ClJ1449}+0856 at z=2},
volume = {833},
issn = {2041-8213},
url = {http://arxiv.org/abs/1611.07976},
doi = {10.3847/2041-8213/833/2/L20},
abstract = {We use HST/WFC3 imaging to study the red population in the IR-selected, X-ray detected, low-mass cluster Cl J1449+0856 at z=2, one of the few bona-fide established clusters discovered at this redshift, and likely a typical progenitor of an average massive cluster today. This study explores the presence and significance of an early red sequence in the core of this structure, investigating the nature of red sequence galaxies, highlighting environmental effects on cluster galaxy populations at high redshift, and at the same time underlining similarities and differences with other distant dense environments. Our results suggest that the red population in the core of Cl J1449+0856 is made of a mixture of quiescent and dusty star-forming galaxies, with a seedling of the future red sequence already growing in the very central cluster region, and already characterising the inner cluster core with respect to lower density environments. On the other hand, the color-magnitude diagram of this cluster is definitely different from that of lower-redshift (z{\textless}1) clusters, as well as of some rare particularly evolved massive clusters at similar redshift, and it is suggestive of a transition phase between active star formation and passive evolution occurring in the proto-cluster and established lower-redshift cluster regimes.},
number = {2},
journal = {The Astrophysical Journal},
author = {Strazzullo, V. and Daddi, E. and Gobat, R. and Valentino, F. and Pannella, M. and Dickinson, M. and Renzini, A. and Brammer, G. and Onodera, M. and Finoguenov, A. and Cimatti, A. and Carollo, C. M. and Arimoto, N.},
month = dec,
year = {2016},
note = {arXiv: 1611.07976},
keywords = {Astrophysics - Astrophysics of Galaxies, Astrophysics - Cosmology and Nongalactic Astrophysics},
pages = {L20},
}Do Some AGN Lack X-ray Emission?. Simmonds, C., Bauer, F. E., Thuan, T. X., Izotov, Y. I., Stern, D., & Harrison, F. A. arXiv:1609.07619 [astro-ph], September, 2016. arXiv: 1609.07619
Paper abstract bibtex
Paper abstract bibtex \$Context:\$ Intermediate-Mass Black Holes (IMBHs) are thought to be the seeds of early Supermassive Black Holes (SMBHs). While \${\textbackslash}gtrsim\$100 IMBH and small SMBH candidates have been identified in recent years, few have been robustly confirmed to date, leaving their number density in considerable doubt. Placing firmer constraints both on the methods used to identify and confirm IMBHs/SMBHs, as well as characterizing the range of host environments that IMBHs/SMBHs likely inhabit is therefore of considerable interest and importance. Additionally, finding significant numbers of IMBHs in metal-poor systems would be particularly intriguing, since such systems may represent local analogs of primordial galaxies, and therefore could provide clues of early accretion processes. \$Aims:\$ Here we study in detail several candidate Active Galactic Nuclei (AGN) found in metal-poor hosts. \$Methods:\$ We utilize new X-ray and optical observations to characterize these metal-poor AGN candidates and compare them against known AGN luminosity relations and well-characterized IMBH/SMBH samples. \$Results:\$ Despite having clear broad optical emission lines that are long-lived (\${\textbackslash}gtrsim\$10–13\textbackslash,yr), these candidate AGN appear to lack associated strong X-ray and hard UV emission, lying at least 1–2 dex off the known AGN correlations. If they are IMBHs/SMBHs, our constraints imply that they either are not actively accreting, their accretion disks are fully obscured along our line-of-sight, or their accretion disks are not producing characteristic high energy emission. Alternatively, if they are not AGN, then their luminous broad emission lines imply production by extreme stellar processes. The latter would have profound implications on the applicability of broad lines for mass estimates of massive black holes.
@article{simmonds_agn_2016,
title = {Do {Some} {AGN} {Lack} {X}-ray {Emission}?},
url = {http://arxiv.org/abs/1609.07619},
abstract = {\$Context:\$ Intermediate-Mass Black Holes (IMBHs) are thought to be the seeds of early Supermassive Black Holes (SMBHs). While \${\textbackslash}gtrsim\$100 IMBH and small SMBH candidates have been identified in recent years, few have been robustly confirmed to date, leaving their number density in considerable doubt. Placing firmer constraints both on the methods used to identify and confirm IMBHs/SMBHs, as well as characterizing the range of host environments that IMBHs/SMBHs likely inhabit is therefore of considerable interest and importance. Additionally, finding significant numbers of IMBHs in metal-poor systems would be particularly intriguing, since such systems may represent local analogs of primordial galaxies, and therefore could provide clues of early accretion processes. \$Aims:\$ Here we study in detail several candidate Active Galactic Nuclei (AGN) found in metal-poor hosts. \$Methods:\$ We utilize new X-ray and optical observations to characterize these metal-poor AGN candidates and compare them against known AGN luminosity relations and well-characterized IMBH/SMBH samples. \$Results:\$ Despite having clear broad optical emission lines that are long-lived (\${\textbackslash}gtrsim\$10--13{\textbackslash},yr), these candidate AGN appear to lack associated strong X-ray and hard UV emission, lying at least 1--2 dex off the known AGN correlations. If they are IMBHs/SMBHs, our constraints imply that they either are not actively accreting, their accretion disks are fully obscured along our line-of-sight, or their accretion disks are not producing characteristic high energy emission. Alternatively, if they are not AGN, then their luminous broad emission lines imply production by extreme stellar processes. The latter would have profound implications on the applicability of broad lines for mass estimates of massive black holes.},
urldate = {2016-10-03},
journal = {arXiv:1609.07619 [astro-ph]},
author = {Simmonds, Charlotte and Bauer, Franz E. and Thuan, Trinh X. and Izotov, Yuri I. and Stern, Daniel and Harrison, Fiona A.},
month = sep,
year = {2016},
note = {arXiv: 1609.07619},
keywords = {Astrophysics - Astrophysics of Galaxies},
}The Evolution of Galaxy Number Density at z \textless 8 and its Implications. Conselice, C. J., Wilkinson, A., Duncan, K., & Mortlock, A. arXiv:1607.03909 [astro-ph], July, 2016. arXiv: 1607.03909
Paper abstract bibtex
Paper abstract bibtex The evolution of the number density of galaxies in the universe, and thus also the total number of galaxies, is a fundamental question with implications for a host of astrophysical problems including galaxy evolution and cosmology. However there has never been a detailed study of this important measurement, nor a clear path to answer it. To address this we use observed galaxy stellar mass functions up to \$z{\textbackslash}sim8\$ to determine how the number densities of galaxies changes as a function of time and mass limit. We show that the increase in the total number density of galaxies (\${\textbackslash}phi_\{{\textbackslash}rm T\}\$), more massive than M\$_\{*\} = 10{\textasciicircum}\{6\}\$ M_0, decreases as \${\textbackslash}phi_\{{\textbackslash}rm T\} {\textbackslash}sim t{\textasciicircum}\{-1\}\$, where \$t\$ is the age of the universe. We further show that this evolution turns-over and rather increases with time at higher mass lower limits of M\$_\{*\}{\textgreater}10{\textasciicircum}\{7\}\$ M_0. By using the M\$_\{*\}=10{\textasciicircum}\{6\}\$ M_0 lower limit we further show that the total number of galaxies in the universe up to \$z = 10\$ is \$2.0{\textasciicircum}\{+0.7\}_\{-0.6\} {\textbackslash}times 10{\textasciicircum}\{12\}\$ (two trillion), almost a factor of ten higher than would be seen in an all sky survey at Hubble Ultra-Deep Field depth. We discuss the implications for these results for galaxy evolution, as well as compare our results with the latest models of galaxy formation. These results also reveal that the cosmic background light in the optical and near-infrared likely arise from these unobserved faint galaxies. We also show how these results solve the question of why the sky at night is dark, otherwise known as Olbers' paradox.
@article{conselice_evolution_2016,
title = {The {Evolution} of {Galaxy} {Number} {Density} at z {\textless} 8 and its {Implications}},
url = {http://arxiv.org/abs/1607.03909},
abstract = {The evolution of the number density of galaxies in the universe, and thus also the total number of galaxies, is a fundamental question with implications for a host of astrophysical problems including galaxy evolution and cosmology. However there has never been a detailed study of this important measurement, nor a clear path to answer it. To address this we use observed galaxy stellar mass functions up to \$z{\textbackslash}sim8\$ to determine how the number densities of galaxies changes as a function of time and mass limit. We show that the increase in the total number density of galaxies (\${\textbackslash}phi\_\{{\textbackslash}rm T\}\$), more massive than M\$\_\{*\} = 10{\textasciicircum}\{6\}\$ M\_0, decreases as \${\textbackslash}phi\_\{{\textbackslash}rm T\} {\textbackslash}sim t{\textasciicircum}\{-1\}\$, where \$t\$ is the age of the universe. We further show that this evolution turns-over and rather increases with time at higher mass lower limits of M\$\_\{*\}{\textgreater}10{\textasciicircum}\{7\}\$ M\_0. By using the M\$\_\{*\}=10{\textasciicircum}\{6\}\$ M\_0 lower limit we further show that the total number of galaxies in the universe up to \$z = 10\$ is \$2.0{\textasciicircum}\{+0.7\}\_\{-0.6\} {\textbackslash}times 10{\textasciicircum}\{12\}\$ (two trillion), almost a factor of ten higher than would be seen in an all sky survey at Hubble Ultra-Deep Field depth. We discuss the implications for these results for galaxy evolution, as well as compare our results with the latest models of galaxy formation. These results also reveal that the cosmic background light in the optical and near-infrared likely arise from these unobserved faint galaxies. We also show how these results solve the question of why the sky at night is dark, otherwise known as Olbers' paradox.},
urldate = {2016-07-18},
journal = {arXiv:1607.03909 [astro-ph]},
author = {Conselice, Christopher J. and Wilkinson, Aaron and Duncan, Kenneth and Mortlock, Alice},
month = jul,
year = {2016},
note = {arXiv: 1607.03909},
keywords = {Astrophysics - Astrophysics of Galaxies},
}An Order Statistics Approach to the Halo Model for Galaxies. Paul, N., Paranjape, A., & Sheth, R. K. arXiv:1610.02485 [astro-ph], October, 2016. arXiv: 1610.02485
Paper abstract bibtex
Paper abstract bibtex We use the Halo Model to explore the implications of assuming that galaxy luminosities in groups are randomly drawn from an underlying luminosity function. We show that even the simplest of such order statistics models – one in which this luminosity function \$p(L)\$ is universal – naturally produces a number of features associated with previous analyses based on the `central plus Poisson satellites' hypothesis. These include the monotonic relation of mean central luminosity with halo mass, the Lognormal distribution around this mean, and the tight relation between the central and satellite mass scales. In stark contrast to observations of galaxy clustering, however, this model predicts \${\textbackslash}textit\{no\}\$ luminosity dependence of large scale clustering. We then show that an extended version of this model, based on the order statistics of a \${\textbackslash}textit\{halo mass dependent\}\$ luminosity function \$p(L{\textbar}m)\$, is in much better agreement with the clustering data as well as satellite luminosities, but systematically under-predicts central luminosities. This brings into focus the idea that central galaxies constitute a distinct population that is affected by different physical processes than are the satellites. We model this physical difference as a statistical brightening of the central luminosities, over and above the order statistics prediction. The magnitude gap between the brightest and second brightest group galaxy is predicted as a by-product, and is also in good agreement with observations. We propose that this order statistics framework provides a useful language in which to compare the Halo Model for galaxies with more physically motivated galaxy formation models
@article{paul_order_2016,
title = {An {Order} {Statistics} {Approach} to the {Halo} {Model} for {Galaxies}},
url = {http://arxiv.org/abs/1610.02485},
abstract = {We use the Halo Model to explore the implications of assuming that galaxy luminosities in groups are randomly drawn from an underlying luminosity function. We show that even the simplest of such order statistics models -- one in which this luminosity function \$p(L)\$ is universal -- naturally produces a number of features associated with previous analyses based on the `central plus Poisson satellites' hypothesis. These include the monotonic relation of mean central luminosity with halo mass, the Lognormal distribution around this mean, and the tight relation between the central and satellite mass scales. In stark contrast to observations of galaxy clustering, however, this model predicts \${\textbackslash}textit\{no\}\$ luminosity dependence of large scale clustering. We then show that an extended version of this model, based on the order statistics of a \${\textbackslash}textit\{halo mass dependent\}\$ luminosity function \$p(L{\textbar}m)\$, is in much better agreement with the clustering data as well as satellite luminosities, but systematically under-predicts central luminosities. This brings into focus the idea that central galaxies constitute a distinct population that is affected by different physical processes than are the satellites. We model this physical difference as a statistical brightening of the central luminosities, over and above the order statistics prediction. The magnitude gap between the brightest and second brightest group galaxy is predicted as a by-product, and is also in good agreement with observations. We propose that this order statistics framework provides a useful language in which to compare the Halo Model for galaxies with more physically motivated galaxy formation models},
urldate = {2016-10-17},
journal = {arXiv:1610.02485 [astro-ph]},
author = {Paul, Niladri and Paranjape, Aseem and Sheth, Ravi K.},
month = oct,
year = {2016},
note = {arXiv: 1610.02485},
keywords = {Astrophysics - Astrophysics of Galaxies, Astrophysics - Cosmology and Nongalactic Astrophysics},
}2015 (5)
The Lyman-Continuum Photon Production Efficiency xi_\ion\ of z\textasciitilde4-5 Galaxies from IRAC-based Halpha Measurements: Implications for the Escape Fraction and Cosmic Reionization. Bouwens, R. J., Smit, R., Labbe, I., Franx, M., Caruana, J., Oesch, P., Stefanon, M., & Rasappu, N. arXiv:1511.08504 [astro-ph], November, 2015. arXiv: 1511.08504
Paper abstract bibtex
Paper abstract bibtex Galaxies represent one of the preferred candidate sources to drive the reionization of the universe. Even as gains are made in mapping the galaxy UV luminosity density to z\textgreater6, significant uncertainties remain regarding the conversion to the implied ionizing emissivity. The relevant unknowns are the Lyman-continuum (LyC) photon production efficiency xi_\ion\ and the escape fraction f_\esc\. As we show here, the first of these unknowns is directly measureable in z=4-5 galaxies, based on the impact the Halpha line has on the observed IRAC fluxes. By computing a LyC photon production rate from the implied Halpha luminosities for a broad selection of z=4-5 galaxies and comparing this against the dust-corrected UV-continuum luminosities, we provide the first-ever direct estimates of the LyC photon production efficiency xi_\ion\ for the z\textgreater\textasciitilde4 galaxy population. We find log_\10\ xi_\ion\/[Hz/ergs] to have a mean value of 25.28_\-0.09\\textasciicircum\+0.10\ and 25.34_\-0.08\\textasciicircum\+0.09\ for sub-L* z=4-5 galaxies adopting Calzetti and SMC dust laws, respectively. Reassuringly, both values are consistent with standardly assumed xi_\ion\'s in reionization models, with a slight preference for higher xi_\ion\'s (by \textasciitilde0.1 dex) adopting the SMC dust law. A modest \textasciitilde0.03-dex increase in these estimates would result if the escape fraction for ionizing photons is non-zero and galaxies dominate the ionizing emissivity at z\textasciitilde4.4. High values of xi_\ion\ (\textasciitilde25.5-25.9 dex) are derived for the bluest galaxies (beta\textless-2.3) in our samples, independent of dust law and consistent with results for a z=7.045 galaxy. Such elevated values of xi_\ion\ would have important consequences, indicating that f_\esc\ cannot be in excess of 13% unless the galaxy UV luminosity function does not extend down to -13 mag or the clumping factor is greater than 3. A low escape fraction would fit well with the low rate of LyC leakage observed at z\textasciitilde3.
@article{bouwens_lyman-continuum_2015,
title = {The {Lyman}-{Continuum} {Photon} {Production} {Efficiency} xi\_\{ion\} of z{\textasciitilde}4-5 {Galaxies} from {IRAC}-based {Halpha} {Measurements}: {Implications} for the {Escape} {Fraction} and {Cosmic} {Reionization}},
shorttitle = {The {Lyman}-{Continuum} {Photon} {Production} {Efficiency} xi\_\{ion\} of z{\textasciitilde}4-5 {Galaxies} from {IRAC}-based {Halpha} {Measurements}},
url = {http://arxiv.org/abs/1511.08504},
abstract = {Galaxies represent one of the preferred candidate sources to drive the reionization of the universe. Even as gains are made in mapping the galaxy UV luminosity density to z{\textgreater}6, significant uncertainties remain regarding the conversion to the implied ionizing emissivity. The relevant unknowns are the Lyman-continuum (LyC) photon production efficiency xi\_\{ion\} and the escape fraction f\_\{esc\}. As we show here, the first of these unknowns is directly measureable in z=4-5 galaxies, based on the impact the Halpha line has on the observed IRAC fluxes. By computing a LyC photon production rate from the implied Halpha luminosities for a broad selection of z=4-5 galaxies and comparing this against the dust-corrected UV-continuum luminosities, we provide the first-ever direct estimates of the LyC photon production efficiency xi\_\{ion\} for the z{\textgreater}{\textasciitilde}4 galaxy population. We find log\_\{10\} xi\_\{ion\}/[Hz/ergs] to have a mean value of 25.28\_\{-0.09\}{\textasciicircum}\{+0.10\} and 25.34\_\{-0.08\}{\textasciicircum}\{+0.09\} for sub-L* z=4-5 galaxies adopting Calzetti and SMC dust laws, respectively. Reassuringly, both values are consistent with standardly assumed xi\_\{ion\}'s in reionization models, with a slight preference for higher xi\_\{ion\}'s (by {\textasciitilde}0.1 dex) adopting the SMC dust law. A modest {\textasciitilde}0.03-dex increase in these estimates would result if the escape fraction for ionizing photons is non-zero and galaxies dominate the ionizing emissivity at z{\textasciitilde}4.4. High values of xi\_\{ion\} ({\textasciitilde}25.5-25.9 dex) are derived for the bluest galaxies (beta{\textless}-2.3) in our samples, independent of dust law and consistent with results for a z=7.045 galaxy. Such elevated values of xi\_\{ion\} would have important consequences, indicating that f\_\{esc\} cannot be in excess of 13\% unless the galaxy UV luminosity function does not extend down to -13 mag or the clumping factor is greater than 3. A low escape fraction would fit well with the low rate of LyC leakage observed at z{\textasciitilde}3.},
urldate = {2016-01-27},
journal = {arXiv:1511.08504 [astro-ph]},
author = {Bouwens, R. J. and Smit, R. and Labbe, I. and Franx, M. and Caruana, J. and Oesch, P. and Stefanon, M. and Rasappu, N.},
month = nov,
year = {2015},
note = {arXiv: 1511.08504},
keywords = {Astrophysics - Astrophysics of Galaxies},
}Robotic Reverberation Mapping of Arp 151. Valenti, S., Sand, D., Barth, A., Horne, K., Treu, T., Raganit, L., Boroson, T., Crawford, S., Pancoast, A., Pei, L., Romero-Colmenero, E., Villforth, C., & Winkler, H. \apjl, 813(2):L36, November, 2015.
doi bibtex
doi bibtex
@ARTICLE{2015ApJ...813L..36V,
author = {{Valenti}, S. and {Sand}, D.~J. and {Barth}, A.~J. and {Horne}, K. and {Treu}, T. and {Raganit}, L. and {Boroson}, T. and {Crawford}, S. and {Pancoast}, A. and {Pei}, L. and {Romero-Colmenero}, E. and {Villforth}, C. and {Winkler}, H.},
title = "{Robotic Reverberation Mapping of Arp 151}",
journal = {\apjl},
keywords = {galaxies: active, galaxies: individual: Arp 151, galaxies: nuclei, galaxies: Seyfert, techniques: spectroscopic, Astrophysics - Astrophysics of Galaxies},
year = 2015,
month = nov,
volume = {813},
number = {2},
eid = {L36},
pages = {L36},
doi = {10.1088/2041-8205/813/2/L36},
archivePrefix = {arXiv},
eprint = {1510.07329},
primaryClass = {astro-ph.GA},
adsurl = {https://ui.adsabs.harvard.edu/abs/2015ApJ...813L..36V},
adsnote = {Provided by the SAO/NASA Astrophysics Data System}
}Baryon effects on the internal structure of LCDM halos in the EAGLE simulations. Schaller, M., Frenk, C. S., Bower, R. G., Theuns, T., Jenkins, A., Schaye, J., Crain, R. A., Furlong, M., Vecchia, C. D., & McCarthy, I. G. Monthly Notices of the Royal Astronomical Society, 451(2):1247–1267, June, 2015. arXiv: 1409.8617
Paper doi abstract bibtex
Paper doi abstract bibtex We investigate the internal structure and density profiles of halos of mass \$10{\textasciicircum}\{10\}-10{\textasciicircum}\{14\}{\textasciitilde}M_{\textbackslash}odot\$ in the Evolution and Assembly of Galaxies and their Environment (EAGLE) simulations. These follow the formation of galaxies in a \${\textbackslash}Lambda\$CDM Universe and include a treatment of the baryon physics thought to be relevant. The EAGLE simulations reproduce the observed present-day galaxy stellar mass function, as well as many other properties of the galaxy population as a function of time. We find significant differences between the masses of halos in the EAGLE simulations and in simulations that follow only the dark matter component. Nevertheless, halos are well described by the Navarro-Frenk-White (NFW) density profile at radii larger than \textasciitilde5% of the virial radius but, closer to the centre, the presence of stars can produce cuspier profiles. Central enhancements in the total mass profile are most important in halos of mass \$10{\textasciicircum}\{12\}-10{\textasciicircum}\{13\}M_{\textbackslash}odot\$, where the stellar fraction peaks. Over the radial range where they are well resolved, the resulting galaxy rotation curves are in very good agreement with observational data for galaxies with stellar mass \$M_*{\textless}5{\textbackslash}times10{\textasciicircum}\{10\}M_{\textbackslash}odot\$. We present an empirical fitting function that describes the total mass profiles and show that its parameters are strongly correlated with halo mass.
@article{schaller_baryon_2015,
title = {Baryon effects on the internal structure of {LCDM} halos in the {EAGLE} simulations},
volume = {451},
issn = {0035-8711, 1365-2966},
url = {http://arxiv.org/abs/1409.8617},
doi = {10.1093/mnras/stv1067},
abstract = {We investigate the internal structure and density profiles of halos of mass \$10{\textasciicircum}\{10\}-10{\textasciicircum}\{14\}{\textasciitilde}M\_{\textbackslash}odot\$ in the Evolution and Assembly of Galaxies and their Environment (EAGLE) simulations. These follow the formation of galaxies in a \${\textbackslash}Lambda\$CDM Universe and include a treatment of the baryon physics thought to be relevant. The EAGLE simulations reproduce the observed present-day galaxy stellar mass function, as well as many other properties of the galaxy population as a function of time. We find significant differences between the masses of halos in the EAGLE simulations and in simulations that follow only the dark matter component. Nevertheless, halos are well described by the Navarro-Frenk-White (NFW) density profile at radii larger than {\textasciitilde}5\% of the virial radius but, closer to the centre, the presence of stars can produce cuspier profiles. Central enhancements in the total mass profile are most important in halos of mass \$10{\textasciicircum}\{12\}-10{\textasciicircum}\{13\}M\_{\textbackslash}odot\$, where the stellar fraction peaks. Over the radial range where they are well resolved, the resulting galaxy rotation curves are in very good agreement with observational data for galaxies with stellar mass \$M\_*{\textless}5{\textbackslash}times10{\textasciicircum}\{10\}M\_{\textbackslash}odot\$. We present an empirical fitting function that describes the total mass profiles and show that its parameters are strongly correlated with halo mass.},
number = {2},
urldate = {2016-01-11},
journal = {Monthly Notices of the Royal Astronomical Society},
author = {Schaller, Matthieu and Frenk, Carlos S. and Bower, Richard G. and Theuns, Tom and Jenkins, Adrian and Schaye, Joop and Crain, Robert A. and Furlong, Michelle and Vecchia, Claudio Dalla and McCarthy, I. G.},
month = jun,
year = {2015},
note = {arXiv: 1409.8617},
keywords = {Astrophysics - Astrophysics of Galaxies, Astrophysics - Cosmology and Nongalactic Astrophysics},
pages = {1247--1267},
}UV Luminosity Functions at redshifts z\textasciitilde4 to z\textasciitilde10: 10000 Galaxies from HST Legacy Fields. Bouwens, R. J., Illingworth, G. D., Oesch, P. A., Trenti, M., Labbe', I., Bradley, L., Carollo, M., van Dokkum, P. G., Gonzalez, V., Holwerda, B., Franx, M., Spitler, L., Smit, R., & Magee, D. The Astrophysical Journal, 803(1):34, April, 2015. arXiv: 1403.4295
Paper doi abstract bibtex
Paper doi abstract bibtex The remarkable HST datasets from the CANDELS, HUDF09, HUDF12, ERS, and BoRG/HIPPIES programs have allowed us to map out the evolution of the UV LF from z\textasciitilde10 to z\textasciitilde4. We have identified 5859, 3001, 857, 481, 217, and 6 galaxy candidates at z\textasciitilde4, z\textasciitilde5, z\textasciitilde6, z\textasciitilde7, z\textasciitilde8, and z\textasciitilde10, respectively from the \textasciitilde1000 arcmin**2 area probed. The selection of z\textasciitilde4-8 galaxies over the five CANDELS fields allows us to assess the cosmic variance; the largest variations are apparent at z\textgreater=7. Our new LF determinations at z\textasciitilde4 and z\textasciitilde5 span a 6-mag baseline (-22.5 to -16 AB mag). These determinations agree well with previous estimates, but the larger samples and volumes probed here result in a more reliable sampling of \textgreaterL* galaxies and allow us to reassess the form of the UV LFs. Our new LF results strengthen our earlier findings to 3.4 sigma significance for a steeper faint-end slope to the UV LF at z\textgreater4, with alpha evolving from alpha=-1.64+/-0.04 at z\textasciitilde4 to alpha=-2.06+/-0.13 at z\textasciitilde7 (and alpha = -2.02+/-0.23 at z\textasciitilde8), consistent with that expected from the evolution of the halo mass function. With our improved constraints at the bright end, we find less evolution in the characteristic luminosity M* over the redshift range z\textasciitilde4 to z\textasciitilde7; the observed evolution in the LF is now largely represented by changes in phi*. No evidence for a non-Schechter-like form to the z\textasciitilde4-8 LFs is found. A simple conditional LF model based on halo growth and evolution in the M/L ratio of halos ((1+z)**-1.5) provides a good representation of the observed evolution.
@article{bouwens_uv_2015,
title = {{UV} {Luminosity} {Functions} at redshifts z{\textasciitilde}4 to z{\textasciitilde}10: 10000 {Galaxies} from {HST} {Legacy} {Fields}},
volume = {803},
issn = {1538-4357},
shorttitle = {{UV} {Luminosity} {Functions} at redshifts z{\textasciitilde}4 to z{\textasciitilde}10},
url = {http://arxiv.org/abs/1403.4295},
doi = {10.1088/0004-637X/803/1/34},
abstract = {The remarkable HST datasets from the CANDELS, HUDF09, HUDF12, ERS, and BoRG/HIPPIES programs have allowed us to map out the evolution of the UV LF from z{\textasciitilde}10 to z{\textasciitilde}4. We have identified 5859, 3001, 857, 481, 217, and 6 galaxy candidates at z{\textasciitilde}4, z{\textasciitilde}5, z{\textasciitilde}6, z{\textasciitilde}7, z{\textasciitilde}8, and z{\textasciitilde}10, respectively from the {\textasciitilde}1000 arcmin**2 area probed. The selection of z{\textasciitilde}4-8 galaxies over the five CANDELS fields allows us to assess the cosmic variance; the largest variations are apparent at z{\textgreater}=7. Our new LF determinations at z{\textasciitilde}4 and z{\textasciitilde}5 span a 6-mag baseline (-22.5 to -16 AB mag). These determinations agree well with previous estimates, but the larger samples and volumes probed here result in a more reliable sampling of {\textgreater}L* galaxies and allow us to reassess the form of the UV LFs. Our new LF results strengthen our earlier findings to 3.4 sigma significance for a steeper faint-end slope to the UV LF at z{\textgreater}4, with alpha evolving from alpha=-1.64+/-0.04 at z{\textasciitilde}4 to alpha=-2.06+/-0.13 at z{\textasciitilde}7 (and alpha = -2.02+/-0.23 at z{\textasciitilde}8), consistent with that expected from the evolution of the halo mass function. With our improved constraints at the bright end, we find less evolution in the characteristic luminosity M* over the redshift range z{\textasciitilde}4 to z{\textasciitilde}7; the observed evolution in the LF is now largely represented by changes in phi*. No evidence for a non-Schechter-like form to the z{\textasciitilde}4-8 LFs is found. A simple conditional LF model based on halo growth and evolution in the M/L ratio of halos ((1+z)**-1.5) provides a good representation of the observed evolution.},
number = {1},
urldate = {2016-07-11},
journal = {The Astrophysical Journal},
author = {Bouwens, R. J. and Illingworth, G. D. and Oesch, P. A. and Trenti, M. and Labbe', I. and Bradley, L. and Carollo, M. and van Dokkum, P. G. and Gonzalez, V. and Holwerda, B. and Franx, M. and Spitler, L. and Smit, R. and Magee, D.},
month = apr,
year = {2015},
note = {arXiv: 1403.4295},
keywords = {Astrophysics - Astrophysics of Galaxies, Astrophysics - Cosmology and Nongalactic Astrophysics},
pages = {34},
}The EAGLE project: simulating the evolution and assembly of galaxies and their environments. Schaye, J., Crain, R. A., Bower, R. G., Furlong, M., Schaller, M., Theuns, T., Dalla Vecchia, C., Frenk, C. S., McCarthy, I. G., Helly, J. C., Jenkins, A., Rosas-Guevara, Y. M., White, S. D. M., Baes, M., Booth, C. M., Camps, P., Navarro, J. F., Qu, Y., Rahmati, A., Sawala, T., Thomas, P. A., & Trayford, J. Monthly Notices of the Royal Astronomical Society, 446(1):521–554, January, 2015. Publisher: Oxford Academic
Paper doi abstract bibtex
Paper doi abstract bibtex Abstract. We introduce the Virgo Consortium's Evolution and Assembly of GaLaxies and their Environments (EAGLE) project, a suite of hydrodynamical simulations
@article{schaye_eagle_2015,
title = {The {EAGLE} project: simulating the evolution and assembly of galaxies and their environments},
volume = {446},
issn = {0035-8711},
shorttitle = {The {EAGLE} project},
url = {https://academic.oup.com/mnras/article/446/1/521/1316115},
doi = {10.1093/mnras/stu2058},
abstract = {Abstract. We introduce the Virgo Consortium's Evolution and Assembly of GaLaxies and their Environments (EAGLE) project, a suite of hydrodynamical simulations},
language = {en},
number = {1},
urldate = {2020-03-26},
journal = {Monthly Notices of the Royal Astronomical Society},
author = {Schaye, Joop and Crain, Robert A. and Bower, Richard G. and Furlong, Michelle and Schaller, Matthieu and Theuns, Tom and Dalla Vecchia, Claudio and Frenk, Carlos S. and McCarthy, I. G. and Helly, John C. and Jenkins, Adrian and Rosas-Guevara, Y. M. and White, Simon D. M. and Baes, Maarten and Booth, C. M. and Camps, Peter and Navarro, Julio F. and Qu, Yan and Rahmati, Alireza and Sawala, Till and Thomas, Peter A. and Trayford, James},
month = jan,
year = {2015},
note = {Publisher: Oxford Academic},
keywords = {Astrophysics - Astrophysics of Galaxies, Astrophysics - Cosmology and Nongalactic Astrophysics},
pages = {521--554},
}2014 (1)
The Rise of SN 2014J in the Nearby Galaxy M82. Goobar, A., Johansson, J., Amanullah, R., Cao, Y., Perley, D., Kasliwal, M., Ferretti, R., Nugent, P., Harris, C., Gal-Yam, A., Ofek, E., Tendulkar, S., Dennefeld, M., Valenti, S., Arcavi, I., Banerjee, D., Venkataraman, V., Joshi, V., Ashok, N., Cenko, S., Diaz, R., Fremling, C., Horesh, A., Howell, D., Kulkarni, S., Papadogiannakis, S., Petrushevska, T., Sand, D., Sollerman, J., Stanishev, V., Bloom, J., Surace, J., Dupuy, T., & Liu, M. \apjl, 784(1):L12, March, 2014.
doi bibtex
doi bibtex
@ARTICLE{2014ApJ...784L..12G,
author = {{Goobar}, A. and {Johansson}, J. and {Amanullah}, R. and {Cao}, Y. and {Perley}, D.~A. and {Kasliwal}, M.~M. and {Ferretti}, R. and {Nugent}, P.~E. and {Harris}, C. and {Gal-Yam}, A. and {Ofek}, E.~O. and {Tendulkar}, S.~P. and {Dennefeld}, M. and {Valenti}, S. and {Arcavi}, I. and {Banerjee}, D.~P.~K. and {Venkataraman}, V. and {Joshi}, V. and {Ashok}, N.~M. and {Cenko}, S.~B. and {Diaz}, R.~F. and {Fremling}, C. and {Horesh}, A. and {Howell}, D.~A. and {Kulkarni}, S.~R. and {Papadogiannakis}, S. and {Petrushevska}, T. and {Sand}, D. and {Sollerman}, J. and {Stanishev}, V. and {Bloom}, J.~S. and {Surace}, J. and {Dupuy}, T.~J. and {Liu}, M.~C.},
title = "{The Rise of SN 2014J in the Nearby Galaxy M82}",
journal = {\apjl},
keywords = {dust, extinction, galaxies: individual: Messier 82, supernovae: individual: SN 2014J, Astrophysics - Astrophysics of Galaxies, Astrophysics - Cosmology and Nongalactic Astrophysics, Astrophysics - Solar and Stellar Astrophysics},
year = 2014,
month = mar,
volume = {784},
number = {1},
eid = {L12},
pages = {L12},
doi = {10.1088/2041-8205/784/1/L12},
archivePrefix = {arXiv},
eprint = {1402.0849},
primaryClass = {astro-ph.GA},
adsurl = {https://ui.adsabs.harvard.edu/abs/2014ApJ...784L..12G},
adsnote = {Provided by the SAO/NASA Astrophysics Data System}
}