SILVERRUSH. VI. A simulation of Lyα emitters in the reionization epoch and a comparison with Subaru Hyper Suprime-Cam survey early data

PASJ: Publications of the Astronomical Society of Japan

Konno, Akira¹  Shimizu, Ikkoh²  Harikane, Yuichi³  Ouchi, Masami⁴  Inoue, Akio K⁵  Hasegawa, Kenji⁶  Ono, Yoshiaki⁷  Yajima, Hidenobu⁸  Kusakabe, Haruka⁹  Higuchi, Ryo⁹  Shibuya, Takatoshi⁹  Shimasaku, Kazuhiro⁹  Ishiyama, Tomoaki^1,10  Lee, Chien-Hsiu^1,11  Umemura, Masayuki^1,12 

[1] Space Science, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka 560-0043, Japan;Astronomical Institute, Tohoku University, 6-3 Aramaki, Aoba-ku, Sendai, Miyagi 980-8578, Japan;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-ku, Tokyo 113-0033, Japan;Department of Environmental Science and Technology, Faculty of Design Technology, Osaka Sangyo University, 3-1-1 Nakagaito, Daito, Osaka 574-8530, Japan;Department of Physics, Graduate School of Science, 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-ku, Tokyo 113-0033, Japan;Frontier Research Institute for Interdisciplinary Sciences, Tohoku University, Sendai 980-8578;Institute for Cosmic Ray Research, The University of Tokyo, 5-1-5 Kashiwa-no-Ha, Kashiwa, Chiba 277-8582, Japan;Institute of Management and Information Technologies, Chiba University, 1-33 Yayoi-cho, Inage-ku, Chiba 263-8522, 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;Theoretical Astrophysics, Department of Earth &

关键词: galaxies: evolution;    galaxies: formation;    galaxies: high-redshift;    (galaxies:) intergalactic medium;    (cosmology:) dark ages, reionization, first stars;    Sun: activity;   

DOI  :  10.1093/pasj/psy048

学科分类：天文学(综合)

来源: Oxford University Press

【 摘 要 】

The survey of Lyman α emitters (LAEs) with the Subaru Hyper Suprime-Cam, called SILVERRUSH (Ouchi et al. 2018, PASJ, 70, S13), is producing massive data of LAEs at z ≳ 6. Here we present LAE simulations to compare the SILVERRUSH data. In 1623 comoving Mpc3 boxes, where numerical radiative transfer calculations of reionization were performed, LAEs have been modeled with physically motivated analytic recipes as a function of halo mass. We have examined 23 models depending on the presence or absence of dispersion of halo Lyα emissivity, dispersion of the halo Lyα optical depth, τα, and halo mass dependence of τα. The unique free parameter in our model, a pivot value of τα, is calibrated so as to reproduce the z = 5.7 Lyα luminosity function (LF) of SILVERRUSH. We compare our model predictions with Lyα LFs at z = 6.6 and 7.3, LAE angular auto-correlation functions (ACFs) at z = 5.7 and 6.6, and LAE fractions in Lyman break galaxies at 5 < z < 7. The Lyα LFs and ACFs are reproduced by multiple models, but the LAE fraction turns out to be the most critical test. The dispersion of τα and the halo mass dependence of τα are essential to explain all observations reasonably. Therefore, a simple model of one-to-one correspondence between halo mass and Lyα luminosity with a constant Lyα escape fraction has been ruled out. Based on our best model, we present a formula to estimate the intergalactic neutral hydrogen fraction, |$x_{\rm H\, \small {I}}$|⁠, from the observed Lyα luminosity density at z ≳ 6. We finally obtain |$x_{\rm H\, \small {I}}=0.5_{-0.3}^{+0.1}$| as a volume-average at z = 7.3.

【 授权许可】

CC BY