GOLDRUSH. II. Clustering of galaxies at z ∼ 4–6 revealed with the half-million dropouts over the 100 deg2 area corresponding to 1 Gpc3

PASJ: Publications of the Astronomical Society of Japan

Konno, Akira¹  Shibuya, Takatoshi²  Lin, Yen-Ting²  Lin, Sheng-Chieh³  Ouchi, Masami⁴  Shimasaku, Kazuhiro⁵  Nishizawa, Atsushi J⁶  Harikane, Yuichi⁶  Coupon, Jean⁶  Ono, Yoshiaki⁶  Behroozi, Peter⁶  Komiyama, Yutaka⁷  Silverman, John⁷  Toshikawa, Jun⁸  Saito, Shun⁸  More, Surhud⁹  Miyazaki, Satoshi^1,10  Akiyama, Masayuki^1,11 

[1] Astronomical Institute, Tohoku University, Aramaki, Aoba-ku, Sendai 980-8578, Japan;Department of Astronomy, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo 113-0033, Japan;Department of Astronomy, University of Geneva, ch. d’Écogia 16, 1290 Versoix, Switzerland;Department of Physics, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo 113-0033, Japan;Department of Physics, University of California, 366 LeConte Hall, MC 7300, Berkeley, CA 94720, USA;Institute for Cosmic Ray Research, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8582, Japan;Institute of Astronomy and Astrophysics, Academia Sinica, 11F of AS/NTU Astronomy-Mathematics Building, No. 1, Sec. 4, Roosevelt Rd, Taipei 10617, Taiwan, ROC;Kavli Institute for the Physics and Mathematics of the Universe (Kavli IPMU, WPI), The University of Tokyo, Kashiwa, Chiba 277-8583, Japan;Max-Planck-Institut für Astrophysik, Karl-Schwarzschild-Starße 1, D-85740 Garching bei München, Germany;National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588, Japan;Research Center for the Early Universe, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo 113-0033, Japan

关键词: galaxies: evolution;    galaxies: formation;    galaxies: high-redshift;   

DOI  :  10.1093/pasj/psx097

学科分类：天文学(综合)

来源: Oxford University Press

【 摘 要 】

We present clustering properties from 579492 Lyman-break galaxies (LBGs) at z ∼ 4–6 over the 100 deg2 sky (corresponding to a 1.4 Gpc3 volume) identified in early data of the Hyper Suprime-Cam (HSC) Subaru Strategic Program survey. We derive angular correlation functions (ACFs) for the HSC LBGs with unprecedentedly high statistical accuracies at z ∼ 4–6, and compare them with the halo occupation distribution (HOD) models. We clearly identify significant ACF excesses in 10″ < θ < 90″, the transition scale between one- and two-halo terms, suggestive of the existence of the non-linear halo bias effect. Combining the HOD models and previous clustering measurements of faint LBGs at z ∼ 4–7, we investigate the dark matter halo mass (Mh) of the z ∼ 4–7 LBGs and its correlation with various physical properties including the star formation rate (SFR), the stellar-to-halo mass ratio (SHMR), and the dark matter accretion rate (⁠|$\skew4\dot{M}_{\,\rm h}$|⁠) over a wide mass range of Mh/M⊙  = 4 × 1010–4 × 1012. We find that the SHMR increases from z ∼ 4 to 7 by a factor of ∼4 at Mh ≃ 1 × 1011 M⊙ , while the SHMR shows no strong evolution in the similar redshift range at Mh ≃ 1 × 1012 M⊙ . Interestingly, we identify a tight relation of SFR|$/\skew4\dot{M}_{\,\rm h}$|–Mh showing no significant evolution beyond 0.15 dex in this wide mass range over z ∼ 4–7. This weak evolution suggests that the SFR|$/\skew4\dot{M}_{\,\rm h}$|–Mh relation is a fundamental relation in high-redshift galaxy formation whose star formation activities are regulated by the dark matter mass assembly. Assuming this fundamental relation, we calculate the cosmic star formation rate densities (SFRDs) over z = 0–10 (a.k.a. the Madau–Lilly plot). The cosmic SFRD evolution based on the fundamental relation agrees with the one obtained by observations, suggesting that the cosmic SFRD increase from z ∼ 10 to 4 − 2 (decrease from z ∼ 4–2 to 0) is mainly driven by the increase of the halo abundance (the decrease of the accretion rate).

【 授权许可】

CC BY