Subaru High-z Exploration of Low-Luminosity Quasars (SHELLQs). II. Discovery of 32 quasars and luminous galaxies at 5.7 < z ≤ 6.8

PASJ: Publications of the Astronomical Society of Japan

Gunn, James E¹  Onoue, Masafusa²  Ono, Yoshiaki²  Imanishi, Masatoshi²  Murayama, Hitoshi²  Strauss, Michael A²  Schulze, Andreas²  Foucaud, Sébastien²  Morokuma, Tomoki³  Izumi, Takuma⁴  Takada, Masahiro⁵  Lupton, Robert H⁵  Sugiyama, Naoshi⁶  Lee, Chien-Hsiu⁷  Tait, Philip J⁸  Tang, Ji-Jia⁹  Toba, Yoshiki⁹  Komiyama, Yutaka⁹  Kikuta, Satoshi^1,10  Shirakata, Hikari^1,11  Niida, Mana^1,11  Price, Paul A^1,11  Harikane, Yuichi^1,12  Utsumi, Yousuke^1,13  Takata, Tadafumi^1,13  Silverman, John D^1,13  Miyazaki, Satoshi^1,14  Matsuoka, Yoshiki^1,14  Bosch, James^1,14  Iwasawa, Kazushi^1,14  Oguri, Masamune^1,14  Kawaguchi, Toshihiro^1,14  Minezaki, Takeo^1,14  Sameshima, Hiroaki^1,14  Nagao, Tohru^1,14  Kohno, Kotaro^1,15  Ouchi, Masami^1,15  Wang, Shiang-Yu^1,15  Akiyama, Masayuki^1,15  Ikeda, Hiroyuki^1,15  Kashikawa, Nobunari^1,16  Asami, Naoko^1,16  Nishizawa, Atsushi J^1,17  Tanaka, Masayuki^1,17  Furusawa, Hisanori^1,18  Goto, Tomotsugu^1,18 

[1] Astronomical Institute, Tohoku University, Aramaki, Aoba-ku, Sendai, Miyagi 980-8578, Japan;Department of Astronomical Science, Graduate University for Advanced Studies (SOKENDAI), 2-21-1 Osawa, Mitaka, Tokyo 181-8588, Japan;Department of Economics, Management and Information Science, Onomichi City University, 1600-2 Hisayamada, Onomichi, Hiroshima 722-8506, Japan;Department of Physics and Astronomy, Shanghai JiaoTong University, 800 Dongchuan Road, Shanghai 200240, China;Department of Physics, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan;Graduate School of Science and Engineering, Ehime University, 2-5 Bunkyo-cho, Matsuyama, Ehime 790-8577, Japan;ICREA and Institut de Ciències del Cosmos, Universitat de Barcelona, IEEC-UB, Martí i Franquès, 1, 08028 Barcelona, Spain;Institute for Advanced Research, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi 464-8602, Japan;Institute for Cosmic Ray Research, The University of Tokyo, Kashiwanoha 5-1-5, Kashiwa, Chiba 277-8582, Japan;Institute of Astronomy and Department of Physics, National Tsing Hua University, 101 Section 2 Kuang Fu Road, Hsinchu 30013, Taiwan;Institute of Astronomy, The University of Tokyo, 2-21-1 Osawa, Mitaka, Tokyo 181-0015, Japan;Japan Professional School of Education, 1-2-3 Kanda Sudacho, Chiyoda, Tokyo 101-0041, Japan;Kavli Institute for the Physics and Mathematics of the Universe, WPI, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8583, Japan;National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588, Japan;Princeton University Observatory, Peyton Hall, 4 Ivy Ln, Princeton, NJ 08544, USA;Research Center for Space and Cosmic Evolution, Ehime University, 2-5 Bunkyo-cho, Matsuyama, Ehime 790-8577, Japan;Research Center for the Early Universe, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan;Subaru Telescope, 650 North A’ohoku Place, Hilo, HI 96720, USA

关键词: galaxies: active;    galaxies: high-redshift;    (galaxies:) quasars: general;    (galaxies:) quasars: supermassive black holes;    (cosmology:) dark ages, reionization, first stars;   

DOI  :  10.1093/pasj/psx046

学科分类：天文学(综合)

来源: Oxford University Press

【 摘 要 】

We present spectroscopic identification of 32 new quasars and luminous galaxies discovered at 5.7 < z ≤ 6.8. This is the second in a series of papers presenting the results of the Subaru High-z Exploration of Low-Luminosity Quasars (SHELLQs) project, which exploits the deep multi-band imaging data produced by the Hyper Suprime-Cam (HSC) Subaru Strategic Program survey. The photometric candidates were selected by a Bayesian probabilistic algorithm, and then observed with spectrographs on the Gran Telescopio Canarias and the Subaru Telescope. Combined with the sample presented in the previous paper of this series, we have now identified 64 HSC sources over about 430 deg2, which include 33 high-z quasars, 14 high-z luminous galaxies, two [O iii] emitters at z ∼ 0.8, and 15 Galactic brown dwarfs. The new quasars have considerably lower luminosity (M1450 ∼ −25 to −22 mag) than most of the previously known high-z quasars. Several of these quasars have luminous (>1043 erg s−1) and narrow (< 500 km s−1) Lyα lines, and also a possible mini broad-absorption-line system of N v λ1240 in the composite spectrum, which clearly separate them from typical quasars. On the other hand, the high-z galaxies have extremely high luminosities (M1450 ∼ −24 to −22 mag) compared to other galaxies found at similar redshifts. With the discovery of these new classes of objects, we are opening up new parameter spaces in the high-z Universe. Further survey observations and follow-up studies of the identified objects, including the construction of the quasar luminosity function at z ∼ 6, are ongoing.

【 授权许可】

CC BY