%0 Generic %1 wang2020significantly %A Wang, Feige %A Davies, Frederick B. %A Yang, Jinyi %A Hennawi, Joseph F. %A Fan, Xiaohui %A Barth, Aaron J. %A Jiang, Linhua %A Wu, Xue-Bing %A Mudd, Dale M. %A Banados, Eduardo %A Bian, Fuyan %A Decarli, Roberto %A Eilers, Anna-Christina %A Farina, Emanuele Paolo %A Venemans, Bram %A Walter, Fabian %A Yue, Minghao %D 2020 %K library %T A Significantly Neutral Intergalactic Medium Around the Luminous z=7 Quasar J0252-0503 %U http://arxiv.org/abs/2004.10877 %X Luminous $z\ge7$ quasars provide direct probes of the evolution of supermassive black holes (SMBHs) and the intergalactic medium (IGM) during the epoch of reionization (EoR). The Ly$\alpha$ damping wing absorption imprinted by neutral hydrogen in the IGM can be detected in a single EoR quasar spectrum, allowing the measurement of the IGM neutral fraction towards that line of sight. However, damping wing features have only been detected in two $z>7$ quasars in previous studies. In this paper, we present new high quality optical and near-infrared spectroscopy of the $z=7.00$ quasar DES J025216.64--050331.8 obtained with Keck/NIRES and Gemini/GMOS. By using the MgII single-epoch virial method, we find that it hosts a $(1.39\pm0.16) \times10^9 ~M_ødot$ SMBH accreting at an Eddington ratio of $łambda_Edd=0.7\pm0.1$, consistent with the values seen in other luminous $z7$ quasars. Furthermore, the Ly$\alpha$ region of the spectrum exhibits a strong damping wing absorption feature. The lack of associated metal absorption in the quasar spectrum indicates that this absorption is imprinted by a neutral IGM. Using a state-of-the-art model developed by Davies et al., we measure a volume-averaged neutral hydrogen fraction at $z=7$ of $x_HI = 0.70^+0.20_-0.23 (^+0.28_-0.48)$ within 68% (95%) confidence intervals when marginalizing over quasar lifetimes of $10^3t_Qłe10^8$ yr. This is the highest IGM neutral fraction yet measured using reionization-era quasar spectra.

@misc{wang2020significantly, abstract = {Luminous $z\ge7$ quasars provide direct probes of the evolution of supermassive black holes (SMBHs) and the intergalactic medium (IGM) during the epoch of reionization (EoR). The Ly$\alpha$ damping wing absorption imprinted by neutral hydrogen in the IGM can be detected in a single EoR quasar spectrum, allowing the measurement of the IGM neutral fraction towards that line of sight. However, damping wing features have only been detected in two $z>7$ quasars in previous studies. In this paper, we present new high quality optical and near-infrared spectroscopy of the $z=7.00$ quasar DES J025216.64--050331.8 obtained with Keck/NIRES and Gemini/GMOS. By using the MgII single-epoch virial method, we find that it hosts a $\rm (1.39\pm0.16) \times10^{9} ~M_\odot$ SMBH accreting at an Eddington ratio of $\lambda_{\rm Edd}=0.7\pm0.1$, consistent with the values seen in other luminous $z\sim 7$ quasars. Furthermore, the Ly$\alpha$ region of the spectrum exhibits a strong damping wing absorption feature. The lack of associated metal absorption in the quasar spectrum indicates that this absorption is imprinted by a neutral IGM. Using a state-of-the-art model developed by Davies et al., we measure a volume-averaged neutral hydrogen fraction at $z=7$ of $\langle x_{\rm HI} \rangle = 0.70^{+0.20}_{-0.23} (^{+0.28}_{-0.48})$ within 68% (95%) confidence intervals when marginalizing over quasar lifetimes of $10^3\le t_{\rm Q}\le10^8$ yr. This is the highest IGM neutral fraction yet measured using reionization-era quasar spectra.}, added-at = {2020-04-24T09:09:09.000+0200}, author = {Wang, Feige and Davies, Frederick B. and Yang, Jinyi and Hennawi, Joseph F. and Fan, Xiaohui and Barth, Aaron J. and Jiang, Linhua and Wu, Xue-Bing and Mudd, Dale M. and Banados, Eduardo and Bian, Fuyan and Decarli, Roberto and Eilers, Anna-Christina and Farina, Emanuele Paolo and Venemans, Bram and Walter, Fabian and Yue, Minghao}, biburl = {https://www.bibsonomy.org/bibtex/2def74b4220a903db709abcde8ca55f99/gpkulkarni}, description = {A Significantly Neutral Intergalactic Medium Around the Luminous z=7 Quasar J0252-0503}, interhash = {dd5edbdc71a531da6c8dfbafba81d5aa}, intrahash = {def74b4220a903db709abcde8ca55f99}, keywords = {library}, note = {cite arxiv:2004.10877Comment: 13 pages, 6 figures. Accepted for publication in The Astrophysical Journal}, timestamp = {2020-04-24T09:09:09.000+0200}, title = {A Significantly Neutral Intergalactic Medium Around the Luminous z=7 Quasar J0252-0503}, url = {http://arxiv.org/abs/2004.10877}, year = 2020 }