Quenching low-mass satellite galaxies: evidence for a threshold ICM density. (arXiv:1902.02820v1 [astro-ph.GA])

Quenching low-mass satellite galaxies: evidence for a threshold ICM density. (arXiv:1902.02820v1 [astro-ph.GA])
<a href="http://arxiv.org/find/astro-ph/1/au:+Roberts_I/0/1/0/all/0/1">Ian D Roberts</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Parker_L/0/1/0/all/0/1">Laura C Parker</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Brown_T/0/1/0/all/0/1">Toby Brown</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Joshi_G/0/1/0/all/0/1">Gandhali D Joshi</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Hlavacek_Larrondo_J/0/1/0/all/0/1">Julie Hlavacek-Larrondo</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Wadsley_J/0/1/0/all/0/1">James Wadsley</a>

We compile a sample of SDSS galaxy clusters with high-quality Chandra X-ray
data to directly study the influence of the dense intra-cluster medium (ICM) on
the quenching of satellite galaxies. We study the quenched fractions of
satellite galaxies as a function of ICM density for low- ($10^9 lesssim
M_star lesssim 10^{10},mathrm{M_odot}$), intermediate- ($10^{10} lesssim
M_star lesssim 10^{10.5},mathrm{M_odot}$), and high-mass ($M_star gtrsim
10^{10.5},mathrm{M_odot}$) satellite galaxies with $>!3000$ satellite
galaxies across 24 low-redshift ($z < 0.1$) clusters. For low-mass galaxies we find evidence for a broken powerlaw trend between satellite quenched fraction and local ICM density. The quenched fraction increases modestly at ICM densities below a threshold before increasing sharply beyond this threshold toward the cluster center. We show that this increase in quenched fraction at high ICM density is well matched by a simple, analytic model of ram pressure stripping. These results are consistent with a picture where low-mass cluster galaxies experience an initial, slow-quenching mode driven by steady gas depletion, followed by rapid quenching associated with ram pressure of cold-gas stripping near (one quarter of the virial radius, on average) the cluster center.

We compile a sample of SDSS galaxy clusters with high-quality Chandra X-ray
data to directly study the influence of the dense intra-cluster medium (ICM) on
the quenching of satellite galaxies. We study the quenched fractions of
satellite galaxies as a function of ICM density for low- ($10^9 lesssim
M_star lesssim 10^{10},mathrm{M_odot}$), intermediate- ($10^{10} lesssim
M_star lesssim 10^{10.5},mathrm{M_odot}$), and high-mass ($M_star gtrsim
10^{10.5},mathrm{M_odot}$) satellite galaxies with $>!3000$ satellite
galaxies across 24 low-redshift ($z < 0.1$) clusters. For low-mass galaxies we
find evidence for a broken powerlaw trend between satellite quenched fraction
and local ICM density. The quenched fraction increases modestly at ICM
densities below a threshold before increasing sharply beyond this threshold
toward the cluster center. We show that this increase in quenched fraction at
high ICM density is well matched by a simple, analytic model of ram pressure
stripping. These results are consistent with a picture where low-mass cluster
galaxies experience an initial, slow-quenching mode driven by steady gas
depletion, followed by rapid quenching associated with ram pressure of cold-gas
stripping near (one quarter of the virial radius, on average) the cluster
center.

http://arxiv.org/icons/sfx.gif

Comments are closed.