Halo-model analysis of the clustering of photometric luminous red galaxies at $0.10 \leq z \leq 1.05$ from the Subaru Hyper Suprime-Cam Survey

TL;DR

This study analyzes the clustering of photometric luminous red galaxies across redshifts 0.1 to 1.05 using halo occupation distribution modeling, revealing the key role of halo mass in galaxy formation and evolution.

Contribution

It provides the first detailed halo occupation analysis of LRGs over this redshift range, highlighting the weak dependence of halo mass on stellar mass for LRGs.

Findings

Dark halo mass $M_{min}$ correlates with LRG number density independently of redshift.

Halo mass of $ extasciitilde 10^{12.5}h^{-1} M_{igodot}$ is critical for halo quenching.

Low-mass LRGs at $z extasciitilde 1$ grow significantly via mergers by $z=0$.

Abstract

We present the clustering analysis of photometric luminous red galaxies (LRGs) at a redshift range of $0.1\leq z \leq 1.05$ using $615,317$ photometric LRGs selected from the Hyper Suprime-Cam Subaru Strategic Program covering $\sim124$ deg$^{2}$. Our sample covers a broad range of stellar masses and photometric redshifts and enables a halo occupation distribution analysis to study the redshift and stellar-mass dependence of dark halo properties of LRGs. We find a tight correlation between the characteristic dark halo mass to host central LRGs, $M_{\min}$, and the number density of LRGs independently of redshifts, indicating that the formation of LRGs is associated with the global environment. The $M_{\min}$ of LRGs depends only weakly on the stellar mass $M_{\star}$ at $M_{\star} \lesssim 10^{10.75}h^{-2} M_{\odot}$ at $0.3<z<1.05$, in contrast to the case for all photometrically selected galaxies for which $M_{\min}$ shows significant dependence on $M_{\star}$ even at low $M_{\star}$. The weak stellar mass dependence is indicative of the dark halo mass being the key parameter for the formation of LRGs rather than the stellar mass. Our result suggests that the halo mass of $\sim 10^{12.5 \pm 0.2}h^{-1} M_{\odot}$ is the critical mass for an efficient halo quenching due to the halo environment. We compare our result with the result of the hydrodynamical simulation to find that low-mass LRGs at $z \sim 1$ will increase their stellar masses by an order magnitude from $z=1$ to $0$ through mergers and satellite accretions, and a large fraction of massive LRGs at $z<0.9$ consist of LRGs that are recently migrated from massive green valley galaxies or those evolved from less massive LRGs through mergers and satellite accretions.