The mass dependence of satellite quenching in Milky Way-like haloes

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 ), with only ∼ 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 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 ), 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.

Under pressure: quenching star formation in low-mass satellite galaxies via stripping

“…This picture is supported by observations of local clusters, which find very few star-forming satellites at stellar masses of 10 9.5 M versus the ∼ 30% quenched fraction measured for group and Milky Way-like hosts (e.g. Smith et al 2012;Boselli et al 2014b;Phillips et al 2015;Sánchez-Janssen et al 2016). …”

“…As first shown by Wheeler et al (2014, see also Slater & Bell 2014Phillips et al 2015), observations of galaxies in the Local Volume point towards a remarkable shift in the efficiency of satellite quenching below a satellite stellar mass of ∼ 10 8 M , such that quenching at low masses proceeds relatively quickly following infall. Recent analysis of much larger samples of Milky Way-like hosts in deep photometric datasets support this picture (Phillips et al in prep), indicating a global critical mass scale for satellite quenching.…”

“…Kimm et al 2009;Kimm, Yi & Khochfar 2011;Wang et al 2014;Hirschmann et al 2014;Phillips et al 2015). While satellites are rapidly quenched -following infall -in the models, analysis of satellite populations identified in the Sloan Digital Sky Survey (SDSS, York et al 2000) instead find that quenching proceeds remarkably slowly, such that a typical e-mail: sfilling@uci.edu † e-mail: cooper@uci.edu ‡ Einstein fellow satellite with M 10 8 M orbits within its host halocontinuing to form stars -for ∼ 3 − 7 Gyr before being quenched (De Lucia et al 2012;Wetzel et al 2013;Wheeler et al 2014).…”

Taking care of business in a flash : constraining the time-scale for low-mass satellite quenching with ELVIS

“…While analysis at these masses is complicated by the fact that some isolated or field systems are quenched independent of any environment-related effects, these independent analyses conclude that the quenching timescale at ∼ 10 10 − 10 11 M increases with decreasing satellite stellar mass, reaching as long as ∼ 5 − 6 Gyr (see also Hirschmann et al 2014). Interestingly, for these most massive satellites, no evidence is found for variation in the quenching timescale with host halo mass (Wetzel et al 2013, but see also Phillips et al 2015).…”

Deep spectroscopy of nearby galaxy clusters – I. Spectroscopic luminosity function of Abell 85

“…However, the environmental quenching of dwarfs is far from ubiquitous (e.g. Phillips et al 2014Phillips et al , 2015Wheeler et al 2014). …”