SILVERRUSH. II. First catalogs and properties of ∼2000 Lyα emitters and blobs at z ∼ 6–7 identified over the 14–21 deg2 sky

PASJ: Publications of the Astronomical Society of Japan

Harikane, Yuichi¹  Nagao, Tohru¹  Shimasaku, Kazuhiro²  Kobayashi, Masakazu A R²  Kashikawa, Nobunari³  Kajisawa, Masaru⁴  Higuchi, Ryo⁴  Shibuya, Takatoshi⁴  Ouchi, Masami⁴  Taniguchi, Yoshiaki⁴  Ono, Yoshiaki⁴  Momose, Rieko⁵  Konno, Akira⁶  Lee, Chien-Hsiu⁷  Wang, Shiang-Yu⁷  Nakajima, Kimihiko⁷  Kusakabe, Haruka⁸  Komiyama, Yutaka⁸  Furusawa, Hisanori⁹  Yuma, Suraphong^1,10  Tanaka, Masayuki^1,10  Goto, Tomotsugu^1,11 

[1] Department of Astronomy, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo 113-0033, Japan;Department of Physics, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo 113-0033, Japan;Faculty of Natural Sciences, National Institute of Technology, Kure College, 2-2-11 Agaminami, Kure, Hiroshima 737-8506, Japan;Institute for Cosmic Ray Research, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8582, Japan;Institute of Astronomy, National Tsing Hua University, 101 Sec. 2, Kuang-Fu Road, Hsinchu 30013, Taiwan;Kavli Institute for the Physics and Mathematics of the Universe (Kavli IPMU, 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;Research Center for Space and Cosmic Evolution, Ehime University, 2-5 Bunkyo-cho, Matsuyama, Ehime 790-8577, Japan;Research Center for the Early Universe, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo 113-0033, Japan;The Graduate University for Advanced Studies (SOKENDAI), 2-21-1 Osawa, Mitaka, Tokyo 181-8588, Japan;The Open University of Japan, 2-11 Wakaba, Mihama-ku, Chiba 261-8586, Japan

关键词: galaxies: formation;    galaxies: high-redshift;    (cosmology:) early universe;   

DOI  :  10.1093/pasj/psx122

学科分类：天文学(综合)

来源: Oxford University Press

【 摘 要 】

We present an unprecedentedly large catalog consisting of 2230 ≳ L* Lyα emitters (LAEs) at z = 5.7 and 6.6 on the 13.8 and 21.2 deg2 sky, respectively, that are identified by the SILVERRUSH program with the first narrow-band imaging data of the Hyper Suprime-Cam (HSC) survey. We confirm that the LAE catalog is reliable on the basis of 96 LAEs whose spectroscopic redshifts are already determined by this program and previous studies. This catalogue is also available online. Based on this catalogue, we derive the rest-frame Lyα equivalent-width distributions of LAEs at z ≃ 5.7–6.6 that are reasonably explained by the exponential profiles with scale lengths of ≃ 120–170 Å, showing no significant evolution from z ≃ 5.7 to z ≃ 6.6. We find that 275 LAEs with large equivalent widths (LEWs) of >240 Å are candidates of young metal poor galaxies and AGNs. We also find that the fraction of LEW LAEs to all LAEs is 4% and 21% at z ≃ 5.7 and z ≃ 6.6, respectively. Our LAE catalog includes 11 Lyα blobs (LABs) that are LAEs with spatially extended Lyα emission with a profile that is clearly distinguished from those of stellar objects at the ≳3σ level. The number density of the LABs at z = 6–7 is ∼10−7–10−6 Mpc−3, being ∼10–100 times lower than those claimed for LABs at z ≃ 2–3, suggestive of disappearing LABs at z ≳ 6, albeit with the different selection methods and criteria for the low and high-z LABs.

【 授权许可】

CC BY