@techreport{2021arXiv210801084E,
	title = {Radio and {Far}-{IR} {Emission} {Associated} with a {Massive} {Star}-forming {Galaxy} {Candidate} at z\${\textbackslash}simeq\$6.8: {A} {Radio}-{Loud} {AGN} in the {Reionization} {Era}?},
	shorttitle = {Radio and {Far}-{IR} {Emission} {Associated} with a {Massive} {Star}-forming {Galaxy} {Candidate} at z\${\textbackslash}simeq\$6.8},
	url = {https://ui.adsabs.harvard.edu/abs/2021arXiv210801084E},
	abstract = {We report the identification of radio (1.4 and 3 GHz) and mid-infrared, far-infrared, and sub-mm (24-850\${\textbackslash}mu\$m) emission at the position of one of 41 UV-bright (\${\textbackslash}mathrm\{M\_\{UV\}{\textasciicircum}\{\}\}{\textbackslash}lesssim-21.25\$) \$z{\textbackslash}simeq6.6-6.9\$ Lyman-break galaxy candidates in the 1.5 deg\${\textasciicircum}2\$ COSMOS field. This source, COS-87259, exhibits a sharp flux discontinuity (factor \${\textgreater}\$3) between two narrow/intermediate bands at 9450 \${\textbackslash}mathring\{A\}\$ and 9700 \${\textbackslash}mathring\{A\}\$ and is undetected in all nine bands blueward of 9600 \${\textbackslash}mathring\{A\}\$, as expected from a Lyman-alpha break at \$z{\textbackslash}simeq6.8\$. The full multi-wavelength (X-ray through radio) data of COS-87529 can be self-consistently explained by a very massive (M\$\_\{{\textbackslash}ast\}=10{\textasciicircum}\{10.8\}\$ M\$\_\{{\textbackslash}odot\}\$) and extremely red (rest-UV slope \${\textbackslash}beta=-0.59\$) \$z{\textbackslash}simeq6.8\$ galaxy with hyperluminous infrared emission (L\$\_\{{\textbackslash}mathrm\{IR\}\}=10{\textasciicircum}\{13.6\}\$ L\$\_\{{\textbackslash}odot\}\$) powered by both an intense burst of highly-obscured star formation (SFR\${\textbackslash}approx\$1800 M\$\_\{{\textbackslash}odot\}\$ yr\${\textasciicircum}\{-1\}\$) and an obscured (\${\textbackslash}tau\_\{{\textbackslash}mathrm\{9.7{\textbackslash}mu m\}\}=7.7{\textbackslash}pm2.5\$) radio-loud (L\$\_\{{\textbackslash}mathrm\{1.4{\textbackslash} GHz\}\}{\textbackslash}sim10{\textasciicircum}\{25.5\}\$ W Hz\${\textasciicircum}\{-1\}\$) AGN. The radio emission is compact (1.04\${\textbackslash}pm\$0.12 arcsec) and exhibits an ultra-steep spectrum between 1.4-3 GHz (\${\textbackslash}alpha=-2.06{\textasciicircum}\{+0.27\}\_\{-0.25\}\$) with evidence of spectral flattening at lower frequencies, consistent with known \$z{\textgreater}4\$ radio galaxies. We also demonstrate that COS-87259 may reside in a significant (11\${\textbackslash}times\$) galaxy overdensity at \$z{\textbackslash}simeq6.6-6.9\$, as common for systems hosting radio-loud AGN. Nonetheless, a spectroscopic redshift will ultimately be required to establish the true nature of COS-87259 as we cannot yet completely rule out low-redshift solutions. If confirmed to lie at \$z{\textbackslash}simeq6.8\$, the properties of COS-87259 would be consistent with a picture wherein AGN and highly-obscured star formation activity are fairly common among very massive (M\$\_\{{\textbackslash}ast\}{\textgreater}10{\textasciicircum}\{10\}\$ M\$\_\{{\textbackslash}odot\}\$) reionization-era galaxies.},
	urldate = {2021-09-07},
	author = {Endsley, Ryan and Stark, Daniel P. and Fan, Xiaohui and Smit, Renske and Wang, Feige and Yang, Jinyi and Hainline, Kevin and Lyu, Jianwei and Bouwens, Rychard and Schouws, Sander},
	month = aug,
	year = {2021},
	note = {Publication Title: arXiv e-prints
ADS Bibcode: 2021arXiv210801084E
Type: article},
	keywords = {Astrophysics - Astrophysics of Galaxies},
}

{"_id":"s7LweTjec4NjCer9b","bibbaseid":"endsley-stark-fan-smit-wang-yang-hainline-lyu-etal-radioandfariremissionassociatedwithamassivestarforminggalaxycandidateatztextbackslashsimeq68aradioloudagninthereionizationera-2021","author_short":["Endsley, R.","Stark, D. P.","Fan, X.","Smit, R.","Wang, F.","Yang, J.","Hainline, K.","Lyu, J.","Bouwens, R.","Schouws, S."],"bibdata":{"bibtype":"techreport","type":"techreport","title":"Radio and Far-IR Emission Associated with a Massive Star-forming Galaxy Candidate at z\\${\\textbackslash}simeq\\$6.8: A Radio-Loud AGN in the Reionization Era?","shorttitle":"Radio and Far-IR Emission Associated with a Massive Star-forming Galaxy Candidate at z\\${\\textbackslash}simeq\\$6.8","url":"https://ui.adsabs.harvard.edu/abs/2021arXiv210801084E","abstract":"We report the identification of radio (1.4 and 3 GHz) and mid-infrared, far-infrared, and sub-mm (24-850\\${\\textbackslash}mu\\$m) emission at the position of one of 41 UV-bright (\\${\\textbackslash}mathrm\\{M_\\{UV\\}{\\textasciicircum}\\{\\}\\}{\\textbackslash}lesssim-21.25\\$) \\$z{\\textbackslash}simeq6.6-6.9\\$ Lyman-break galaxy candidates in the 1.5 deg\\${\\textasciicircum}2\\$ COSMOS field. This source, COS-87259, exhibits a sharp flux discontinuity (factor \\${\\textgreater}\\$3) between two narrow/intermediate bands at 9450 \\${\\textbackslash}mathring\\{A\\}\\$ and 9700 \\${\\textbackslash}mathring\\{A\\}\\$ and is undetected in all nine bands blueward of 9600 \\${\\textbackslash}mathring\\{A\\}\\$, as expected from a Lyman-alpha break at \\$z{\\textbackslash}simeq6.8\\$. The full multi-wavelength (X-ray through radio) data of COS-87529 can be self-consistently explained by a very massive (M\\$_\\{{\\textbackslash}ast\\}=10{\\textasciicircum}\\{10.8\\}\\$ M\\$_\\{{\\textbackslash}odot\\}\\$) and extremely red (rest-UV slope \\${\\textbackslash}beta=-0.59\\$) \\$z{\\textbackslash}simeq6.8\\$ galaxy with hyperluminous infrared emission (L\\$_\\{{\\textbackslash}mathrm\\{IR\\}\\}=10{\\textasciicircum}\\{13.6\\}\\$ L\\$_\\{{\\textbackslash}odot\\}\\$) powered by both an intense burst of highly-obscured star formation (SFR\\${\\textbackslash}approx\\$1800 M\\$_\\{{\\textbackslash}odot\\}\\$ yr\\${\\textasciicircum}\\{-1\\}\\$) and an obscured (\\${\\textbackslash}tau_\\{{\\textbackslash}mathrm\\{9.7{\\textbackslash}mu m\\}\\}=7.7{\\textbackslash}pm2.5\\$) radio-loud (L\\$_\\{{\\textbackslash}mathrm\\{1.4{\\textbackslash} GHz\\}\\}{\\textbackslash}sim10{\\textasciicircum}\\{25.5\\}\\$ W Hz\\${\\textasciicircum}\\{-1\\}\\$) AGN. The radio emission is compact (1.04\\${\\textbackslash}pm\\$0.12 arcsec) and exhibits an ultra-steep spectrum between 1.4-3 GHz (\\${\\textbackslash}alpha=-2.06{\\textasciicircum}\\{+0.27\\}_\\{-0.25\\}\\$) with evidence of spectral flattening at lower frequencies, consistent with known \\$z{\\textgreater}4\\$ radio galaxies. We also demonstrate that COS-87259 may reside in a significant (11\\${\\textbackslash}times\\$) galaxy overdensity at \\$z{\\textbackslash}simeq6.6-6.9\\$, as common for systems hosting radio-loud AGN. Nonetheless, a spectroscopic redshift will ultimately be required to establish the true nature of COS-87259 as we cannot yet completely rule out low-redshift solutions. If confirmed to lie at \\$z{\\textbackslash}simeq6.8\\$, the properties of COS-87259 would be consistent with a picture wherein AGN and highly-obscured star formation activity are fairly common among very massive (M\\$_\\{{\\textbackslash}ast\\}{\\textgreater}10{\\textasciicircum}\\{10\\}\\$ M\\$_\\{{\\textbackslash}odot\\}\\$) reionization-era galaxies.","urldate":"2021-09-07","author":[{"propositions":[],"lastnames":["Endsley"],"firstnames":["Ryan"],"suffixes":[]},{"propositions":[],"lastnames":["Stark"],"firstnames":["Daniel","P."],"suffixes":[]},{"propositions":[],"lastnames":["Fan"],"firstnames":["Xiaohui"],"suffixes":[]},{"propositions":[],"lastnames":["Smit"],"firstnames":["Renske"],"suffixes":[]},{"propositions":[],"lastnames":["Wang"],"firstnames":["Feige"],"suffixes":[]},{"propositions":[],"lastnames":["Yang"],"firstnames":["Jinyi"],"suffixes":[]},{"propositions":[],"lastnames":["Hainline"],"firstnames":["Kevin"],"suffixes":[]},{"propositions":[],"lastnames":["Lyu"],"firstnames":["Jianwei"],"suffixes":[]},{"propositions":[],"lastnames":["Bouwens"],"firstnames":["Rychard"],"suffixes":[]},{"propositions":[],"lastnames":["Schouws"],"firstnames":["Sander"],"suffixes":[]}],"month":"August","year":"2021","note":"Publication Title: arXiv e-prints ADS Bibcode: 2021arXiv210801084E Type: article","keywords":"Astrophysics - Astrophysics of Galaxies","bibtex":"@techreport{2021arXiv210801084E,\n\ttitle = {Radio and {Far}-{IR} {Emission} {Associated} with a {Massive} {Star}-forming {Galaxy} {Candidate} at z\\${\\textbackslash}simeq\\$6.8: {A} {Radio}-{Loud} {AGN} in the {Reionization} {Era}?},\n\tshorttitle = {Radio and {Far}-{IR} {Emission} {Associated} with a {Massive} {Star}-forming {Galaxy} {Candidate} at z\\${\\textbackslash}simeq\\$6.8},\n\turl = {https://ui.adsabs.harvard.edu/abs/2021arXiv210801084E},\n\tabstract = {We report the identification of radio (1.4 and 3 GHz) and mid-infrared, far-infrared, and sub-mm (24-850\\${\\textbackslash}mu\\$m) emission at the position of one of 41 UV-bright (\\${\\textbackslash}mathrm\\{M\\_\\{UV\\}{\\textasciicircum}\\{\\}\\}{\\textbackslash}lesssim-21.25\\$) \\$z{\\textbackslash}simeq6.6-6.9\\$ Lyman-break galaxy candidates in the 1.5 deg\\${\\textasciicircum}2\\$ COSMOS field. This source, COS-87259, exhibits a sharp flux discontinuity (factor \\${\\textgreater}\\$3) between two narrow/intermediate bands at 9450 \\${\\textbackslash}mathring\\{A\\}\\$ and 9700 \\${\\textbackslash}mathring\\{A\\}\\$ and is undetected in all nine bands blueward of 9600 \\${\\textbackslash}mathring\\{A\\}\\$, as expected from a Lyman-alpha break at \\$z{\\textbackslash}simeq6.8\\$. The full multi-wavelength (X-ray through radio) data of COS-87529 can be self-consistently explained by a very massive (M\\$\\_\\{{\\textbackslash}ast\\}=10{\\textasciicircum}\\{10.8\\}\\$ M\\$\\_\\{{\\textbackslash}odot\\}\\$) and extremely red (rest-UV slope \\${\\textbackslash}beta=-0.59\\$) \\$z{\\textbackslash}simeq6.8\\$ galaxy with hyperluminous infrared emission (L\\$\\_\\{{\\textbackslash}mathrm\\{IR\\}\\}=10{\\textasciicircum}\\{13.6\\}\\$ L\\$\\_\\{{\\textbackslash}odot\\}\\$) powered by both an intense burst of highly-obscured star formation (SFR\\${\\textbackslash}approx\\$1800 M\\$\\_\\{{\\textbackslash}odot\\}\\$ yr\\${\\textasciicircum}\\{-1\\}\\$) and an obscured (\\${\\textbackslash}tau\\_\\{{\\textbackslash}mathrm\\{9.7{\\textbackslash}mu m\\}\\}=7.7{\\textbackslash}pm2.5\\$) radio-loud (L\\$\\_\\{{\\textbackslash}mathrm\\{1.4{\\textbackslash} GHz\\}\\}{\\textbackslash}sim10{\\textasciicircum}\\{25.5\\}\\$ W Hz\\${\\textasciicircum}\\{-1\\}\\$) AGN. The radio emission is compact (1.04\\${\\textbackslash}pm\\$0.12 arcsec) and exhibits an ultra-steep spectrum between 1.4-3 GHz (\\${\\textbackslash}alpha=-2.06{\\textasciicircum}\\{+0.27\\}\\_\\{-0.25\\}\\$) with evidence of spectral flattening at lower frequencies, consistent with known \\$z{\\textgreater}4\\$ radio galaxies. We also demonstrate that COS-87259 may reside in a significant (11\\${\\textbackslash}times\\$) galaxy overdensity at \\$z{\\textbackslash}simeq6.6-6.9\\$, as common for systems hosting radio-loud AGN. Nonetheless, a spectroscopic redshift will ultimately be required to establish the true nature of COS-87259 as we cannot yet completely rule out low-redshift solutions. If confirmed to lie at \\$z{\\textbackslash}simeq6.8\\$, the properties of COS-87259 would be consistent with a picture wherein AGN and highly-obscured star formation activity are fairly common among very massive (M\\$\\_\\{{\\textbackslash}ast\\}{\\textgreater}10{\\textasciicircum}\\{10\\}\\$ M\\$\\_\\{{\\textbackslash}odot\\}\\$) reionization-era galaxies.},\n\turldate = {2021-09-07},\n\tauthor = {Endsley, Ryan and Stark, Daniel P. and Fan, Xiaohui and Smit, Renske and Wang, Feige and Yang, Jinyi and Hainline, Kevin and Lyu, Jianwei and Bouwens, Rychard and Schouws, Sander},\n\tmonth = aug,\n\tyear = {2021},\n\tnote = {Publication Title: arXiv e-prints\nADS Bibcode: 2021arXiv210801084E\nType: article},\n\tkeywords = {Astrophysics - Astrophysics of Galaxies},\n}\n\n","author_short":["Endsley, R.","Stark, D. P.","Fan, X.","Smit, R.","Wang, F.","Yang, J.","Hainline, K.","Lyu, J.","Bouwens, R.","Schouws, S."],"key":"2021arXiv210801084E","id":"2021arXiv210801084E","bibbaseid":"endsley-stark-fan-smit-wang-yang-hainline-lyu-etal-radioandfariremissionassociatedwithamassivestarforminggalaxycandidateatztextbackslashsimeq68aradioloudagninthereionizationera-2021","role":"author","urls":{"Paper":"https://ui.adsabs.harvard.edu/abs/2021arXiv210801084E"},"keyword":["Astrophysics - Astrophysics of Galaxies"],"metadata":{"authorlinks":{}}},"bibtype":"techreport","biburl":"https://bibbase.org/zotero/polyphant","dataSources":["7gvjSdWrEu7z5vjjj"],"keywords":["astrophysics - astrophysics of galaxies"],"search_terms":["radio","far","emission","associated","massive","star","forming","galaxy","candidate","textbackslash","simeq","radio","loud","agn","reionization","era","endsley","stark","fan","smit","wang","yang","hainline","lyu","bouwens","schouws"],"title":"Radio and Far-IR Emission Associated with a Massive Star-forming Galaxy Candidate at z\\${\\textbackslash}simeq\\$6.8: A Radio-Loud AGN in the Reionization Era?","year":2021}