Effects of the Dissolution of Low-Concentration Globular Clusters on the Evolution of Globular Cluster Systems

Abstract

We investigate the role of dissolution of low-concentration clusters due to mass loss through stellar evolution on the evolution of the properties of globular cluster systems (GCSs) in elliptical galaxies. Our simulations show that, for an initial mass-concentration relationship based on that inferred from Galactic globular clusters, dissolution of low-concentration clusters leads to the disruption of a large number of clusters. A power-law initial globular cluster system mass function (GCMF) similar to that observed in young cluster systems in merging galaxies is transformed by this dissolution into a bell-shaped GCMF with a mean mass similar to that of old GCSs for all the galaxies investigated. Two-body relaxation and dynamical friction, which are also included in our simulations, subsequently lead to an additional significant evolution and disruption of the population of clusters. As shown previously, when these processes act on a bell-shaped GCMF with a mean mass similar to that of old GCSs, they do not significantly alter the value of the mean mass. The final GCMFs are bell-shaped with similar peaks at different radii within galaxies and between different galaxies, in agreement with current observations.