@article{fc59fb6a38fc4dceb4b0489ddee2a4f7,
title = "Discovery of the First Low-luminosity Quasar at z > 7",
abstract = " 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 M 1450 = -24.13 0.08 mag and the bolometric luminosity is erg s -1 . 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 , thus indicating a moderate mass accretion rate with an Eddington ratio . 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.",
keywords = "Dark ages, first stars, galaxies: active, galaxies: high-redshift, intergalactic medium, quasars: general, quasars: supermassive black holes, reionization",
author = "Yoshiki Matsuoka and Masafusa Onoue and Nobunari Kashikawa and Strauss, {Michael A.} and Kazushi Iwasawa and Lee, {Chien Hsiu} and Masatoshi Imanishi and Tohru Nagao and Masayuki Akiyama and Naoko Asami and James Bosch and Hisanori Furusawa and Tomotsugu Goto and Gunn, {James E.} and Yuichi Harikane and Hiroyuki Ikeda and Takuma Izumi and Toshihiro Kawaguchi and Nanako Kato and Satoshi Kikuta and Kotaro Kohno and Yutaka Komiyama and Shuhei Koyama and Lupton, {Robert H.} and Takeo Minezaki and Satoshi Miyazaki and Hitoshi Murayama and Mana Niida and Nishizawa, {Atsushi J.} and Akatoki Noboriguchi and Masamune Oguri and Yoshiaki Ono and Masami Ouchi and Price, {Paul A.} and Hiroaki Sameshima and Andreas Schulze and Hikari Shirakata and Silverman, {John D.} and Naoshi Sugiyama and Tait, {Philip J.} and Masahiro Takada and Tadafumi Takata and Masayuki Tanaka and Tang, {Ji Jia} and Yoshiki Toba and Yousuke Utsumi and Wang, {Shiang Yu} and Takuji Yamashita",
note = "Funding Information: The Pan-STARRS1 Surveys (PS1) have been made possible through contributions of the Institute for Astronomy, the University of Hawaii, the Pan-STARRS Project Office, the Max-Planck Society and its participating institutes, the Max Planck Institute for Astronomy, Heidelberg and the Max Planck Institute for Extraterrestrial Physics, Garching, The Johns Hopkins University, Durham University, the University of Edinburgh, Queen{\textquoteright}s University Belfast, the Harvard-Smithsonian Center for Astrophysics, the Las Cumbres Observatory Global Telescope Network Incorporated, the National Central University of Taiwan, the Space Telescope Science Institute, the National Aeronautics and Space Administration under grant No. NNX08AR22G issued through the Planetary Science Division of the NASA Science Mission Directorate, the National Science Foundation under grant No. AST-1238877, the University of Maryland, and Eotvos Lorand University (ELTE). Funding Information: The Hyper Suprime-Cam (HSC) collaboration includes the astronomical communities of Japan and Taiwan, and Princeton University. The HSC instrumentation and software were developed by the National Astronomical Observatory of Japan (NAOJ), the Kavli Institute for the Physics and Mathematics of the Universe (Kavli IPMU), the University of Tokyo, the High Energy Accelerator Research Organization (KEK), the Academia Sinica Institute for Astronomy and Astrophysics in Taiwan (ASIAA), and Princeton University. Funding was contributed by the FIRST program from Japanese Cabinet Office, the Ministry of Education, Culture, Sports, Science and Technology (MEXT), the Japan Society for the Promotion of Science (JSPS), Japan Science and Technology Agency (JST), the Toray Science Foundation, NAOJ, Kavli IPMU, KEK, ASIAA, and Princeton University. Funding Information: IRAF is distributed by the National Optical Astronomy Observatory, which is operated by the Association of Universities for Research in Astronomy (AURA) under a cooperative agreement with the National Science Foundation. Funding Information: This work is also based on observations obtained at the Gemini Observatory and processed using the Gemini IRAF package. The Observatory is operated by the Association of Universities for Research in Astronomy, Inc., under a cooperative agreement with the NSF on behalf of the Gemini partnership: the National Science Foundation (United States), the National Research Council (Canada), CONICYT (Chile), Ministerio de Ciencia, Tecnolog{\'i}a e Innovaci{\'o}n Productiva (Argentina), and Minist{\'e}rio da Ci{\^e}ncia, Tecnologia e Inova{\c c}{\~a}o (Brazil). Funding Information: Y.M. was supported by the Japan Society for the Promotion of Science (JSPS) KAKENHI grant No. JP17H04830 and the Mitsubishi Foundation grant No. 30140. N.K. acknowledges supports from the JSPS grant 15H03645. K.I. acknowledges support by the Spanish MINECO under grant No. AYA2016-76012-C3-1-P and MDM-2014-0369 of ICCUB (Unidad de Excelencia “Mar{\'i}a deMaeztu”). Publisher Copyright: {\textcopyright} 2019. The American Astronomical Society.",
year = "2019",
month = feb,
day = "10",
doi = "10.3847/2041-8213/ab0216",
language = "English (US)",
volume = "872",
journal = "Astrophysical Journal Letters",
issn = "2041-8205",
publisher = "IOP Publishing Ltd.",
number = "1",
}