Photometric Objects Around Cosmic Webs (PAC) Delineated in a Spectroscopic survey. II. Morphology, Color and Size Dependences of the Stellar-halo Mass Relation for Massive Galaxies

TL;DR

This study measures how galaxy morphology, size, and color influence the stellar-halo mass relation at high mass and redshift, revealing that more compact, red galaxies tend to reside in more massive halos.

Contribution

It introduces the PAC method to analyze satellite distributions around massive galaxies, demonstrating a clear dependence of halo mass on galaxy morphology, size, and color.

Findings

More compact galaxies have higher satellite counts.

Halo mass increases with galaxy compactness and redness.

Red galaxies reside in halos over twice as massive as blue ones.

Abstract

In this paper, we report a robust measurement of the morphology, color and galaxy size dependences of the stellar-halo mass relation (SHMR) at the high mass end ($10^{11.3}{\rm M_{\odot}}<M_{\star}<10^{11.7}{\rm M_{\odot}}$) at redshift $z_s\sim0.6$ (Throughout the paper, we use $z_s$ for redshift, $z$ for the z-band magnitude.). Applying our method, Photometric objects Around Cosmic webs (PAC), developed in a previous work to CMASS and HSC-SSP observations, we measure the excess surface density ($\bar{n}_2w_p(r_p)$) of satellites around massive central galaxies with different morphologies indicated by S\'ersic index $n$. We find that more compact (larger $n$) central galaxies are surrounded by more satellites. With the abundance matching method, we estimate halo mass for the central galaxies, and find that halo mass is increased monotonically with $n$, solid evidence for a morphology dependence of SHMR. Specifically, our results show that the most compact galaxies ($n>6$) have the halo mass around 5.5 times larger than the disk galaxies ($n<2$). Similarly, using the effective radius $R_e$ and the rest-frame $u-r$ color, we find that red (large) galaxies reside in halos that are in average $2.6$ ($2.3$) times more massive than those hosting blue (small) galaxies.