Globular cluster systems in extreme environments

By extreme environments we refer to fossil groups, and thecenter of the massive galaxy cluster Abell 1689. These systems arelarge, massive, distant, and represent the link between regulargalaxies and galaxy clusters.We use globular clusters (GCs), which are appealing tracers of galaxystructure and indicators of formation mechanisms as our tool. Thesestellar systems are very old and dense, and so they survive galacticinteractions without being disaggregated.Using ACS/HST data, we studied for the first time the GC population inthree representative fossil groups: the nearest (NGC6482), theprototype (NGC1132), and the most massive known to date (ESO306-G17).In addition, we studied the very rich GC system in Abell 1689, withthe goals of testing the existence of a universal GC formationefficiency per total mass, and exploring the relationship between GCsand dark matter.