@article{pacucci_are_2022,
	title = {Are the {Newly}-{Discovered} \$z {\textbackslash}sim 13\$ {Drop}-out {Sources} {Starburst} {Galaxies} or {Quasars}?},
	url = {http://arxiv.org/abs/2201.00823},
	abstract = {The detection of two \$z {\textbackslash}sim 13\$ galaxy candidates (Harikane et al. 2021b) has opened a new window on galaxy formation at an era only \$330\$ Myr after the Big Bang. Here, we investigate the physical nature of these sources: are we witnessing star forming galaxies or quasars at such early epochs? If powered by star formation, the observed ultraviolet (UV) luminosities and number densities can be jointly explained if: (i) these galaxies are extreme star-formers with star formation rates \$5-25{\textbackslash}times\$ higher than those expected from extrapolations of average lower-redshift relations; (ii) the star formation efficiency increases with halo mass and is countered by increasing dust attenuation from \$z {\textbackslash}sim 10-5\$; (iii) they form stars with an extremely top-heavy initial mass function. The quasar hypothesis is also plausible, with the UV luminosity produced by black holes of \${\textbackslash}sim 10{\textasciicircum}8 {\textbackslash}, {\textbackslash}mathrm\{M\_\{{\textbackslash}odot\}\}\$ accreting at or slightly above the Eddington rate (\$f\_\{{\textbackslash}rm Edd\}{\textbackslash}sim 1.0\$). This black hole mass at \$z {\textbackslash}sim 13\$ would require challenging, but not implausible, growth parameters, in line with what required for \$z{\textbackslash}sim 7.5\$ quasars detected thus far. If spectroscopically confirmed, these two sources will represent a remarkable laboratory to study the Universe at previously inaccessible redshifts.},
	urldate = {2022-01-05},
	journal = {arXiv:2201.00823 [astro-ph]},
	author = {Pacucci, Fabio and Dayal, Pratika and Harikane, Yuichi and Inoue, Akio K. and Loeb, Abraham},
	month = jan,
	year = {2022},
	note = {arXiv: 2201.00823},
	keywords = {Astrophysics - Astrophysics of Galaxies, Astrophysics - Cosmology and Nongalactic Astrophysics, Astrophysics - High Energy Astrophysical Phenomena},
}

{"_id":"XzDZoWFcXdFWnRvWL","bibbaseid":"pacucci-dayal-harikane-inoue-loeb-arethenewlydiscoveredztextbackslashsim13dropoutsourcesstarburstgalaxiesorquasars-2022","author_short":["Pacucci, F.","Dayal, P.","Harikane, Y.","Inoue, A. K.","Loeb, A."],"bibdata":{"bibtype":"article","type":"article","title":"Are the Newly-Discovered \\$z {\\textbackslash}sim 13\\$ Drop-out Sources Starburst Galaxies or Quasars?","url":"http://arxiv.org/abs/2201.00823","abstract":"The detection of two \\$z {\\textbackslash}sim 13\\$ galaxy candidates (Harikane et al. 2021b) has opened a new window on galaxy formation at an era only \\$330\\$ Myr after the Big Bang. Here, we investigate the physical nature of these sources: are we witnessing star forming galaxies or quasars at such early epochs? If powered by star formation, the observed ultraviolet (UV) luminosities and number densities can be jointly explained if: (i) these galaxies are extreme star-formers with star formation rates \\$5-25{\\textbackslash}times\\$ higher than those expected from extrapolations of average lower-redshift relations; (ii) the star formation efficiency increases with halo mass and is countered by increasing dust attenuation from \\$z {\\textbackslash}sim 10-5\\$; (iii) they form stars with an extremely top-heavy initial mass function. The quasar hypothesis is also plausible, with the UV luminosity produced by black holes of \\${\\textbackslash}sim 10{\\textasciicircum}8 {\\textbackslash}, {\\textbackslash}mathrm\\{M_\\{{\\textbackslash}odot\\}\\}\\$ accreting at or slightly above the Eddington rate (\\$f_\\{{\\textbackslash}rm Edd\\}{\\textbackslash}sim 1.0\\$). This black hole mass at \\$z {\\textbackslash}sim 13\\$ would require challenging, but not implausible, growth parameters, in line with what required for \\$z{\\textbackslash}sim 7.5\\$ quasars detected thus far. If spectroscopically confirmed, these two sources will represent a remarkable laboratory to study the Universe at previously inaccessible redshifts.","urldate":"2022-01-05","journal":"arXiv:2201.00823 [astro-ph]","author":[{"propositions":[],"lastnames":["Pacucci"],"firstnames":["Fabio"],"suffixes":[]},{"propositions":[],"lastnames":["Dayal"],"firstnames":["Pratika"],"suffixes":[]},{"propositions":[],"lastnames":["Harikane"],"firstnames":["Yuichi"],"suffixes":[]},{"propositions":[],"lastnames":["Inoue"],"firstnames":["Akio","K."],"suffixes":[]},{"propositions":[],"lastnames":["Loeb"],"firstnames":["Abraham"],"suffixes":[]}],"month":"January","year":"2022","note":"arXiv: 2201.00823","keywords":"Astrophysics - Astrophysics of Galaxies, Astrophysics - Cosmology and Nongalactic Astrophysics, Astrophysics - High Energy Astrophysical Phenomena","bibtex":"@article{pacucci_are_2022,\n\ttitle = {Are the {Newly}-{Discovered} \\$z {\\textbackslash}sim 13\\$ {Drop}-out {Sources} {Starburst} {Galaxies} or {Quasars}?},\n\turl = {http://arxiv.org/abs/2201.00823},\n\tabstract = {The detection of two \\$z {\\textbackslash}sim 13\\$ galaxy candidates (Harikane et al. 2021b) has opened a new window on galaxy formation at an era only \\$330\\$ Myr after the Big Bang. Here, we investigate the physical nature of these sources: are we witnessing star forming galaxies or quasars at such early epochs? If powered by star formation, the observed ultraviolet (UV) luminosities and number densities can be jointly explained if: (i) these galaxies are extreme star-formers with star formation rates \\$5-25{\\textbackslash}times\\$ higher than those expected from extrapolations of average lower-redshift relations; (ii) the star formation efficiency increases with halo mass and is countered by increasing dust attenuation from \\$z {\\textbackslash}sim 10-5\\$; (iii) they form stars with an extremely top-heavy initial mass function. The quasar hypothesis is also plausible, with the UV luminosity produced by black holes of \\${\\textbackslash}sim 10{\\textasciicircum}8 {\\textbackslash}, {\\textbackslash}mathrm\\{M\\_\\{{\\textbackslash}odot\\}\\}\\$ accreting at or slightly above the Eddington rate (\\$f\\_\\{{\\textbackslash}rm Edd\\}{\\textbackslash}sim 1.0\\$). This black hole mass at \\$z {\\textbackslash}sim 13\\$ would require challenging, but not implausible, growth parameters, in line with what required for \\$z{\\textbackslash}sim 7.5\\$ quasars detected thus far. If spectroscopically confirmed, these two sources will represent a remarkable laboratory to study the Universe at previously inaccessible redshifts.},\n\turldate = {2022-01-05},\n\tjournal = {arXiv:2201.00823 [astro-ph]},\n\tauthor = {Pacucci, Fabio and Dayal, Pratika and Harikane, Yuichi and Inoue, Akio K. and Loeb, Abraham},\n\tmonth = jan,\n\tyear = {2022},\n\tnote = {arXiv: 2201.00823},\n\tkeywords = {Astrophysics - Astrophysics of Galaxies, Astrophysics - Cosmology and Nongalactic Astrophysics, Astrophysics - High Energy Astrophysical Phenomena},\n}\n\n","author_short":["Pacucci, F.","Dayal, P.","Harikane, Y.","Inoue, A. K.","Loeb, A."],"key":"pacucci_are_2022","id":"pacucci_are_2022","bibbaseid":"pacucci-dayal-harikane-inoue-loeb-arethenewlydiscoveredztextbackslashsim13dropoutsourcesstarburstgalaxiesorquasars-2022","role":"author","urls":{"Paper":"http://arxiv.org/abs/2201.00823"},"keyword":["Astrophysics - Astrophysics of Galaxies","Astrophysics - Cosmology and Nongalactic Astrophysics","Astrophysics - High Energy Astrophysical Phenomena"],"metadata":{"authorlinks":{}}},"bibtype":"article","biburl":"https://bibbase.org/zotero/polyphant","dataSources":["7gvjSdWrEu7z5vjjj"],"keywords":["astrophysics - astrophysics of galaxies","astrophysics - cosmology and nongalactic astrophysics","astrophysics - high energy astrophysical phenomena"],"search_terms":["newly","discovered","textbackslash","sim","drop","out","sources","starburst","galaxies","quasars","pacucci","dayal","harikane","inoue","loeb"],"title":"Are the Newly-Discovered \\$z {\\textbackslash}sim 13\\$ Drop-out Sources Starburst Galaxies or Quasars?","year":2022}