X-ray sources in compact stellar systems in the Fornax Cluster

Compact stellar systems (CSS) range in mass from globular clusters (GCs), through the more recently discovered ultracompact dwarfs (UCDs), to the rare compact elliptical galaxies. Given their intermediate position, the origin of UCDs, and hence whether they should be counted as galaxies or star clusters, remains unclear. In this paper, we compare the population of X-ray point sources (expected to ...