Systematic Identification of LAEs for Visible Exploration and Reionization Research Using Subaru HSC (SILVERRUSH). I. Program strategy and clustering properties of ∼2000 Lyα emitters at z = 6–7 over the 0.3–0.5 Gpc2 survey area

PASJ: Publications of the Astronomical Society of Japan

Komiyama, Yutaka¹  Matsuda, Yuichi¹  Konno, Akira²  Ono, Yoshiaki²  Higuchi, Ryo³  Nakajima, Kimihiko⁴  Shimasaku, Kazuhiro⁵  Inoue, Akio K⁶  Shibuya, Takatoshi⁷  Saito, Tomoki⁷  Ouchi, Masami⁷  Hasegawa, Kenji⁷  Taniguchi, Yoshiaki⁷  Nagao, Tohru⁷  Harikane, Yuichi⁸  Wang, Shiang-Yu⁹  Umemura, Masayuki^1,10  Mori, Masao^1,10  Kobayashi, Masakazu^1,11  Kajisawa, Masaru^1,12 

[1] Center for Computational Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8577, Japan;Department of Astronomy, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo 113-0033, Japan;Department of Environmental Science and Technology, Faculty of Design Technology, Osaka Sangyo University, 3-1-1 Nagaito, Daito, Osaka 574-8530, Japan;Department of Physics and Astrophysics, Nagoya University Furo-cho, Chikusa-ku, Nagoya, Aichi 464-8602, 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;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 Open University of Japan, Wakaba 2-11, Mihama-ku, Chiba 261-8586, Japan

关键词: galaxies: formation;    galaxies: high-redshift;    cosmology: observations;   

DOI  :  10.1093/pasj/psx074

学科分类：天文学(综合)

来源: Oxford University Press

【 摘 要 】

We present the SILVERRUSH program strategy and clustering properties investigated with ∼2000 Lyα emitters (LAEs) at z = 5.7 and 6.6 found in the early data of the Hyper Suprime-Cam (HSC) Subaru Strategic Program survey exploiting the carefully designed narrow-band filters. We derive angular correlation functions with the unprecedentedly large samples of LAEs at z = 6–7 over the large total area of 14–21 deg2 corresponding to 0.3–0.5 comoving Gpc2. We obtain the average large-scale bias values of bavg = 4.1 ± 0.2 (4.5 ± 0.6) at z = 5.7 (z = 6.6) for ≳ L* LAEs, indicating a weak evolution of LAE clustering from z = 5.7 to 6.6. We compare the LAE clustering results with two independent theoretical models that suggest an increase of an LAE clustering signal by the patchy ionized bubbles at the epoch of reionization (EoR), and estimate the neutral hydrogen fraction to be |$x_{\rm H\,{\small I}}=0.15^{+0.15}_{-0.15}$| at z = 6.6. Based on the halo occupation distribution models, we find that the ≳ L* LAEs are hosted by dark-matter halos with an average mass of |$\log (\left\langle M_{\rm h} \right\rangle /M_\odot ) =11.1^{+0.2}_{-0.4}$| (⁠|$10.8^{+0.3}_{-0.5}$|⁠) at z = 5.7 (6.6) with a Lyα duty cycle of 1% or less, where the results of z = 6.6 LAEs may be slightly biased, due to the increase of the clustering signal at the EoR. Our clustering analysis reveals the low-mass nature of ≳ L* LAEs at z = 6–7, and that these LAEs probably evolve into massive super-L* galaxies in the present-day universe.

【 授权许可】

CC BY