The Burrell Schmidt Deep Virgo Survey: Tidal Debris, Galaxy Halos, and Diffuse Intracluster Light in the Virgo Cluster

TL;DR

This deep imaging survey of the Virgo Cluster reveals the distribution and properties of diffuse intracluster light, galaxy halos, and tidal debris, providing insights into the cluster's assembly history and the origins of its diffuse components.

Contribution

First detailed deep imaging analysis of Virgo's intracluster light, galaxy halos, and tidal features, highlighting the role of environment and galaxy interactions in ICL formation.

Findings

Most ICL is in Virgo core and W' cloud, less in subcluster B.

Virgo's ICL fraction is 7-15%, smaller than expected for evolved clusters.

Detected a large ultra-diffuse galaxy undergoing tidal disruption.

Abstract

We present a deep imaging survey of the Virgo Cluster, designed to study the connection between cluster galaxies and Virgo's diffuse intracluster light (ICL). Our observations span roughly 16 square degrees and reach a 3-sigma depth of mu(B)=29.5 and mu(V)=28.5 mag/arcsec^2. At these depths, the limiting systematic uncertainties are astrophysical: scattered starlight from foreground Galactic dust, and variations in faint background sources. The dust-scattered starlight is well-traced by deep far-infrared imaging, making it distinguishable from true Virgo diffuse light. Our imaging maps the Virgo core around M87 and the adjacent M86/M84 region, in subcluster B around M49, and in the more distant W' cloud around NGC 4365. Most of the detected ICL is found in the Virgo core and within the W' cloud, with little evidence for extensive ICL in subcluster B. The large amount of diffuse light seen in the infalling W' cloud likely illustrates the importance of the group environment for generating ICL. The bulk of the detected ICL is fairly red (B-V=0.7-0.9), indicative of old stellar populations. We estimate a total Virgo ICL fraction of 7-15%, somewhat smaller than expected for massive, evolved clusters, suggesting that Virgo is still growing its ICL component. We trace M87's extremely boxy halo out to ~ 150 kpc, and show that the current stripping rate of low luminosity galaxies is insufficient to have built M87's outer halo over a Hubble time. Finally, we identify another large ultra-diffuse galaxy in Virgo, likely in the process of being shredded by the cluster tidal field.