Evolution of globular cluster systems in elliptical galaxies -- II. Power-law initial mass function

Abstract

We have studied the evolution of globular cluster systems (GCS) in elliptical galaxies with a power-law initial GCS mass function (GCMF) ($f(M) \propto M^{-\alpha}$) similar to that predicted by some theoretical studies of globular clusters formation and to that of young cluster systems observed in merging galaxies. We have carried out a survey over a large number of different host galaxies and we have considered different values for the index, $\alpha$, of the initial power-law GCMF ($\alpha=1.5,1.8,2.0$); we show the dependence of the main GCS final properties (mean mass and dispersion of the final GCMF, fraction of surviving clusters, radial gradient of the GCMF parameters) on the structure of the host galaxy and on the slope of the initial GCMF. For a subsample of host galaxies with values of effective masses and radii equal to those determined using observational data for a number of giant, normal and dwarf galaxies our results show that the relation between the final GCMF properties and those of the host galaxies as well as the dependence of the final GCMF parameters on the galactocentric distance within individual galaxies differ from those observed in old GCS: the values of the final GCS mean mass are in general smaller (4.2 < log M_final < 5.0) than those observed and the galaxy-to-galaxy dispersion of logM_final is larger than that reported by observational analyses. The results are compared with those of a companion paper in which we investigated the evolution of GCS with a log-normal initial GCMF and in which the final GCS properties were perfectly consistent with observations.