%0 Generic %1 yang2020poniuaena %A Yang, Jinyi %A Wang, Feige %A Fan, Xiaohui %A Hennawi, Joseph F. %A Davies, Frederick B. %A Yue, Minghao %A Banados, Eduardo %A Wu, Xue-Bing %A Venemans, Bram %A Barth, Aaron J. %A Bian, Fuyan %A Boutsia, Konstantina %A Decarli, Roberto %A Farina, Emanuele Paolo %A Green, Richard %A Jiang, Linhua %A Li, Jiang-Tao %A Mazzucchelli, Chiara %A Walter, Fabian %D 2020 %K library %T P\=oniu\=a'ena: A Luminous $z=7.5$ Quasar Hosting a 1.5 Billion Solar Mass Black Hole %U http://arxiv.org/abs/2006.13452 %X We report the discovery of a luminous quasar, J1007+2115 at $z=7.515$ ("P\=oniu\=a'ena"), from our wide-field reionization-era quasar survey. J1007+2115 is the second quasar now known at $z>7.5$, deep into the reionization epoch. The quasar is powered by a $(1.5\pm0.2)\times10^9$ $M_ødot$ supermassive black hole (SMBH), based on its broad MgII emission-line profile from Gemini and Keck near-IR spectroscopy. The SMBH in J1007+2115 is twice as massive as that in quasar J1342+0928 at $z=7.54$, the current quasar redshift record holder. The existence of such a massive SMBH just 700 million years after the Big Bang significantly challenges models of the earliest SMBH growth. Model assumptions of Eddington-limited accretion and a radiative efficiency of 0.1 require a seed black hole of $10^4$ $M_ødot$ at $z=30$. This requirement suggests either a massive black hole seed as a result of direct collapse or earlier periods of rapid black hole growth with hyper-Eddington accretion and/or a low radiative efficiency. We measure the damping wing signature imprinted by neutral hydrogen absorption in the intergalactic medium (IGM) on J1007+2115's Ly$\alpha$ line profile, and find that it is weaker than that of J1342+0928 and two other $z\gtrsim7$ quasars. We estimate an IGM volume-averaged neutral fraction $łangle x\rm_HI\rangle=0.39^+0.22_-0.13$. This range of values suggests a patchy reionization history toward different IGM sightlines. We detect the 158 $\mu$m C II emission line in J1007+2115 with ALMA; this line centroid yields a systemic redshift of $z=7.5149\pm0.0004$ and indicates a star formation rate of $\sim210$ $M_ødot$ yr$^-1$ in its host galaxy.

@misc{yang2020poniuaena, abstract = {We report the discovery of a luminous quasar, J1007+2115 at $z=7.515$ ("P\={o}niu\={a}'ena"), from our wide-field reionization-era quasar survey. J1007+2115 is the second quasar now known at $z>7.5$, deep into the reionization epoch. The quasar is powered by a $(1.5\pm0.2)\times10^9$ $M_{\odot}$ supermassive black hole (SMBH), based on its broad MgII emission-line profile from Gemini and Keck near-IR spectroscopy. The SMBH in J1007+2115 is twice as massive as that in quasar J1342+0928 at $z=7.54$, the current quasar redshift record holder. The existence of such a massive SMBH just 700 million years after the Big Bang significantly challenges models of the earliest SMBH growth. Model assumptions of Eddington-limited accretion and a radiative efficiency of 0.1 require a seed black hole of $\gtrsim 10^{4}$ $M_{\odot}$ at $z=30$. This requirement suggests either a massive black hole seed as a result of direct collapse or earlier periods of rapid black hole growth with hyper-Eddington accretion and/or a low radiative efficiency. We measure the damping wing signature imprinted by neutral hydrogen absorption in the intergalactic medium (IGM) on J1007+2115's Ly$\alpha$ line profile, and find that it is weaker than that of J1342+0928 and two other $z\gtrsim7$ quasars. We estimate an IGM volume-averaged neutral fraction $\langle x\rm_{HI}\rangle=0.39^{+0.22}_{-0.13}$. This range of values suggests a patchy reionization history toward different IGM sightlines. We detect the 158 $\mu$m [C II] emission line in J1007+2115 with ALMA; this line centroid yields a systemic redshift of $z=7.5149\pm0.0004$ and indicates a star formation rate of $\sim210$ $M_{\odot}$ yr$^{-1}$ in its host galaxy.}, added-at = {2020-06-25T07:05:17.000+0200}, author = {Yang, Jinyi and Wang, Feige and Fan, Xiaohui and Hennawi, Joseph F. and Davies, Frederick B. and Yue, Minghao and Banados, Eduardo and Wu, Xue-Bing and Venemans, Bram and Barth, Aaron J. and Bian, Fuyan and Boutsia, Konstantina and Decarli, Roberto and Farina, Emanuele Paolo and Green, Richard and Jiang, Linhua and Li, Jiang-Tao and Mazzucchelli, Chiara and Walter, Fabian}, biburl = {https://www.bibsonomy.org/bibtex/253c120fbebaceb6b58b7270e1c06d9e0/gpkulkarni}, description = {P\={o}niu\={a}'ena: A Luminous $z=7.5$ Quasar Hosting a 1.5 Billion Solar Mass Black Hole}, interhash = {3f64afa67304db4585ea165c653fdcb4}, intrahash = {53c120fbebaceb6b58b7270e1c06d9e0}, keywords = {library}, note = {cite arxiv:2006.13452Comment: 9 pages, 4 figures, ApJL in press}, timestamp = {2020-06-25T07:05:17.000+0200}, title = {P\={o}niu\={a}'ena: A Luminous $z=7.5$ Quasar Hosting a 1.5 Billion Solar Mass Black Hole}, url = {http://arxiv.org/abs/2006.13452}, year = 2020 }