Discovery of the First Low-Luminosity Quasar at z > 7. (arXiv:1901.10487v1 [astro-ph.GA])

Discovery of the First Low-Luminosity Quasar at z > 7. (arXiv:1901.10487v1 [astro-ph.GA])
<a href="http://arxiv.org/find/astro-ph/1/au:+Matsuoka_Y/0/1/0/all/0/1">Yoshiki Matsuoka</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Onoue_M/0/1/0/all/0/1">Masafusa Onoue</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Kashikawa_N/0/1/0/all/0/1">Nobunari Kashikawa</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Strauss_M/0/1/0/all/0/1">Michael A. Strauss</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Iwasawa_K/0/1/0/all/0/1">Kazushi Iwasawa</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Lee_C/0/1/0/all/0/1">Chien-Hsiu Lee</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Imanishi_M/0/1/0/all/0/1">Masatoshi Imanishi</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Nagao_T/0/1/0/all/0/1">Tohru Nagao</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Akiyama_M/0/1/0/all/0/1">Masayuki Akiyama</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Asami_N/0/1/0/all/0/1">Naoko Asami</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Bosch_J/0/1/0/all/0/1">James Bosch</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Furusawa_H/0/1/0/all/0/1">Hisanori Furusawa</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Goto_T/0/1/0/all/0/1">Tomotsugu Goto</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Gunn_J/0/1/0/all/0/1">James E. Gunn</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Harikane_Y/0/1/0/all/0/1">Yuichi Harikane</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Ikeda_H/0/1/0/all/0/1">Hiroyuki Ikeda</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Izumi_T/0/1/0/all/0/1">Takuma Izumi</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Kawaguchi_T/0/1/0/all/0/1">Toshihiro Kawaguchi</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Kato_N/0/1/0/all/0/1">Nanako Kato</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Kikuta_S/0/1/0/all/0/1">Satoshi Kikuta</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Kohno_K/0/1/0/all/0/1">Kotaro Kohno</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Komiyama_Y/0/1/0/all/0/1">Yutaka Komiyama</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Koyama_S/0/1/0/all/0/1">Shuhei Koyama</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Lupton_R/0/1/0/all/0/1">Robert H. Lupton</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Minezaki_T/0/1/0/all/0/1">Takeo Minezaki</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Miyazaki_S/0/1/0/all/0/1">Satoshi Miyazaki</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Murayama_H/0/1/0/all/0/1">Hitoshi Murayama</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Niida_M/0/1/0/all/0/1">Mana Niida</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Nishizawa_A/0/1/0/all/0/1">Atsushi J. Nishizawa</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Noboriguchi_A/0/1/0/all/0/1">Akatoki Noboriguchi</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Oguri_M/0/1/0/all/0/1">Masamune Oguri</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Ono_Y/0/1/0/all/0/1">Yoshiaki Ono</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Ouchi_M/0/1/0/all/0/1">Masami Ouchi</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Price_P/0/1/0/all/0/1">Paul A. Price</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Sameshima_H/0/1/0/all/0/1">Hiroaki Sameshima</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Schulze_A/0/1/0/all/0/1">Andreas Schulze</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Shirakata_H/0/1/0/all/0/1">Hikari Shirakata</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Silverman_J/0/1/0/all/0/1">John D. Silverman</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Sugiyama_N/0/1/0/all/0/1">Naoshi Sugiyama</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Tait_P/0/1/0/all/0/1">Philip J. Tait</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Takada_M/0/1/0/all/0/1">Masahiro Takada</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Takata_T/0/1/0/all/0/1">Tadafumi Takata</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Tanaka_M/0/1/0/all/0/1">Masayuki Tanaka</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Tang_J/0/1/0/all/0/1">Ji-Jia Tang</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Toba_Y/0/1/0/all/0/1">Yoshiki Toba</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Utsumi_Y/0/1/0/all/0/1">Yousuke Utsumi</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Wang_S/0/1/0/all/0/1">Shiang-Yu Wang</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Yamashita_T/0/1/0/all/0/1">Takuji Yamashita</a>

We report the discovery of a quasar at z = 7.07, which was selected from the
deep multi-band imaging data collected by the Hyper Suprime-Cam (HSC) Subaru
Strategic Program survey. This quasar, HSC J124353.93+010038.5, has an order of
magnitude lower luminosity than do the other known quasars at z > 7. The
rest-frame ultraviolet absolute magnitude is M1450 = -24.13 +/- 0.08 mag and
the bolometric luminosity is Lbol = (1.4 +/- 0.1) x 10^{46} erg/s. Its spectrum
in the optical to near-infrared shows strong emission lines, and shows evidence
for a fast gas outflow, as the C IV line is blueshifted and there is indication
of broad absorption lines. The Mg II-based black hole mass is Mbh = (3.3 +/-
2.0) x 10^8 Msun, thus indicating a moderate mass accretion rate with an
Eddington ratio 0.34 +/- 0.20. It is the first z > 7 quasar with sub-Eddington
accretion, besides being the third most distant quasar, known to date. The
luminosity and black hole mass are comparable to, or even lower than, those
measured for the majority of low-z quasars discovered by the Sloan Digital Sky
Survey, and thus this quasar likely represents a z > 7 counterpart to quasars
commonly observed in the low-z universe.

http://arxiv.org/icons/sfx.gif