The Mass Dependance of Satellite Quenching in Milky Way-like Halos

TL;DR

This study investigates how satellite galaxy quenching depends on satellite and host galaxy properties in Milky Way-like halos, revealing low overall quenching efficiency but strong host-dependent effects, especially at lower satellite masses.

Contribution

It provides new insights into the mass and host property dependence of satellite quenching in Milky Way-like environments, extending previous findings to lower satellite masses.

Findings

Satellite quenching efficiency is roughly 20% and independent of satellite stellar mass.

Satellites of passive hosts are more likely to be quenched than those of star-forming hosts.

More massive halos quench their satellites more effectively.

Abstract

Using the Sloan Digital Sky Survey, we examine the quenching of satellite galaxies around isolated Milky Way-like hosts in the local Universe. We find that the efficiency of satellite quenching around isolated galaxies is low and roughly constant over two orders of magnitude in satellite stellar mass ($M_{*}$ = $10^{8.5}-10^{10.5} \, M_{\odot}$), with only $\sim~20\%$ of systems quenched as a result of environmental processes. While largely independent of satellite stellar mass, satellite quenching does exhibit clear dependence on the properties of the host. We show that satellites of passive hosts are substantially more likely to be quenched than those of star-forming hosts, and we present evidence that more massive halos quench their satellites more efficiently. These results extend trends seen previously in more massive host halos and for higher satellite masses. Taken together, it appears that galaxies with stellar masses larger than about $10^{8}~M_{\odot}$ are uniformly resistant to environmental quenching, with the relative harshness of the host environment likely serving as the primary driver of satellite quenching. At lower stellar masses ($< 10^{8}~M_{\odot}$), however, observations of the Local Group suggest that the vast majority of satellite galaxies are quenched, potentially pointing towards a characteristic satellite mass scale below which quenching efficiency increases dramatically.