Evolution of globular cluster systems in three galaxies of the Fornax cluster

Abstract

We studied and compared the radial profiles of globular clusters and of the stellar bulge component in three galaxies of the Fornax cluster observed with the WFPC2 of the HST. A careful comparative analysis of these distributions confirms that stars are more concentrated toward the galactic centres than globular clusters, in agreement with what was observed in many other galaxies. If the observed difference is the result of evolution of the globular cluster system sstarting from initial profiles similar to those of the halo--bulge stellar components, a relevant fraction of their mass (74%, 47%, 52% for NGC 1379, NGC 1399 and NGC 1404, respectively) is disappeared in the inner regions, likely contributing to the nuclear field population, local dynamics and high energy phenomena in the primeval life of the galaxy. An indication in favour of the evolutionary interpretation of the difference between the globular cluster system and stellar bulge radial profiles is given by the positive correlation we found between the value of the mass lost from the GCS and the central galactic black hole mass in the set of seven galaxies for which these data are available.