The fate of dwarf galaxies in clusters and the origin of intracluster stars

Abstract

The main goal of this paper is to compare the relative importance of destruction by tides vs. destruction by mergers, in order to assess if tidal destruction of galaxies in clusters is a viable scenario for explaining the origin of intracluster stars. We have designed a simple algorithm for simulating the evolution of isolated clusters. The distribution of galaxies in the cluster is evolved using a direct gravitational N-body algorithm combined with a subgrid treatment of physical processes such as mergers, tidal disruption, and galaxy harassment. Using this algorithm, we have performed a total of 148 simulations. Our main results are:• destruction of dwarf galaxies by mergers dominates over destruction by tides, and • the destruction of galaxies by tides is sufficient to explain the observed intracluster light in clusters.

The growth of intracluster light in XCS-HSC galaxy clusters from 0.1 < z < 0.5

“…for our work, 20-40%, see Contini et al 2014, Rudick et al 2011 for some typical SAM results). Barai et al (2009), using a numerical prescription, simulated the build-up of intracluster stars using several different cluster mass profiles (e.g. Perseus-like to Virgolike) while considering the morphology of the galaxies contained within the cluster (e.g.…”

The Galaxy Population of Low-Redshift Abell Clusters

“…Some support for this idea is garnered from the fact that blue dwarfs are very similar to the low-mass dwarf spheroidal galaxies, which are expected to undergo tidal disruption in the cluster environment (Thompson & Gregory 1993;Gallagher & Wyse 1994;Moore et al 1999;Quilis et al 2000;Boyce et al 2001;Barai et al 2007). These galaxies may potentially be the source of tidally disrupted material that helped to form the halo of cD galaxies Hilker et al 1999Hilker et al , 2003.…”

“…The red dwarf galaxies, however, may be part of a population of nucleated dwarfs (van den Bergh 1986;Caldwell & Bothun 1987;Lisker et al 2007) that would be expected to have a deeper gravitational potential well than the more diffuse dwarf spheroidal population. This would allow them to more efficiently survive cluster tidal forces against disruption than the dwarf spheroidals (i.e., non-nucleated dwarf galaxies; see, for example, Thompson & Gregory 1993;Trujillo et al 2002;Barai et al 2007;Lisker et al 2007). Nucleated cluster dwarf galaxies have been shown to have colors that are redder on average than non-nucleated dwarfs (e.g., Caldwell & Bothun 1987;Lisker et al 2007), and thus support the suggestion that the red dwarf population is composed mainly of nucleated dwarf galaxies.…”

The Fate of Dwarf Galaxies in Clusters and the Origin of Intracluster Stars. Ii. Cosmological Simulations

“…While these various processes might contribute to some of the observed ICL, it is generally accepted that most intracluster stars were formed inside galaxies, and were later dispersed into the intracluster space by galaxy interactions taking place during the evolution of the clusters. This likely results from tidal stripping or tidal destruction of galaxies during close encounters (Weil et al 1997;Gregg & West 1998;Gnedin 2003;Willman et al 2004;Feldmeier et al 2004a;Rudick et al 2006;Conroy et al 2007;Purcell et al 2007, Barai et al 2009, hereafter Paper I, Yang et al 2009Wu & Jiang 2009;Rudick et al 2009;Puchwein et al 2010), though an important contribution could also be provided by stars ejected during galactic mergers (Murante et al 2007). The ICL tends to be more concentrated than the galactic light (Aguerri et al 2005), which is interpreted as evidence for the role of galaxy collisions in the origin of the ICL (Zibetti et al 2005).…”