Quantifying the origin and distribution of intracluster Light in a Fornax-Like Cluster

Abstract

Using a cosmological $N$-body simulation, we investigate the origin and\ndistribution of stars in the intracluster light (ICL) of a Fornax-like cluster.\nIn a dark matter only simulation we identify a halo which, at $z=0$, has $M_200\n\\simeq 4.1 \\times 10^{13}M_{sun}$ and $r_{200} = 700kpc$, and replace infalling\nsubhalos with models that include spheroid and disc components. As they fall\ninto the cluster, the stars in some of these galaxies are stripped from their\nhosts, and form the ICL. We consider the separate contributions to the ICL from\nstars which originate in the haloes and the discs of the galaxies. We find that\ndisc ICL stars are more centrally concentrated than halo ICL stars. The\nmajority of the disc ICL stars are associated with one initially disc-dominated\ngalaxy that falls to the centre of the cluster and is heavily disrupted,\nproducing part of the cD galaxy. At radial distances greater than 200kpc, well\nbeyond the stellar envelope of the cD galaxy, stars formerly from the stellar\nhaloes of galaxies dominate the ICL. Therefore at large distances, the ICL\npopulation is dominated by older stars.\n