We present clustering analysis results from 10,381 Lyman break galaxies (LBGs) at z ∼ 4-7, identified in the Hubble legacy deep imaging and new complimentary large-area Subaru/Hyper Suprime-Cam data. We measure the angular correlation functions of these LBGs at z ∼ 4, 5, 6, and 7 and fit these measurements using halo occupation distribution (HOD) models that provide an estimate of halo masses, Mh ~ (1 - 20 ) x 1011 M⊙. Our Mh estimates agree with those obtained by previous clustering studies in a UV-magnitude versus Mh plane and allow us to calculate stellar-to-halo mass ratios (SHMRs) of LBGs. By comparison with the Z ~ 0 SHMR, we identify evolution of the SHMR from z ~ 0 to z ~ 4 and from z ~ 4 to z ~ 7 at the > 98% confidence levels. The SHMR decreases by a factor of ∼2 from z ~ 0 to 4 and increases by a factor of ∼4 from z ~ 4 to 7 at the dark matter halo mass of Mh ~ 1011 M⊙. We compare our SHMRs with results of a hydrodynamic simulation and a semianalytic model and find that these theoretical studies do not predict the SHMR increase from to 7. We obtain the baryon conversion efficiency (BCE) of LBGs at z ~ 4 and find that the BCE increases with increasing dark matter halo mass. Finally, we compare our clustering+HOD estimates with results from abundance matching techniques and conclude that the Mh estimates of the clustering+HOD analyses agree with those of the simple abundance matching within a factor of 3, and that the agreement improves when using more sophisticated abundance matching techniques that include subhalos, incompleteness, and/or evolution in the star formation and stellar mass functions.
Y. Harikane et al., "Evolution of Stellar-To-Halo Mass Ratio at Z = 0-7 Identified by Clustering Analysis with the Hubble Legacy Imaging and Early Subaru/Hyper Suprime-Cam Survey Data," Astrophysical Journal, vol. 821, no. 2, Institute of Physics - IOP Publishing, Apr 2016.
The definitive version is available at https://doi.org/10.3847/0004-637X/821/2/123
Keywords and Phrases
Galaxies: Evolution; Galaxies: Formation; Galaxies: High-redshift
International Standard Serial Number (ISSN)
Article - Journal
© 2016 The American Astronomical Society, All rights reserved.
01 Apr 2016