Publication Date

2008

Abstract

In this work we investigate the evolution of the mass function of the Galactic globular cluster system (GCMF) taking into account the effects of stellar evolution, two-body relaxation, disk shocking and dynamical friction on the evolution of individual globular clusters. We have adopted a log-normal initial GCMF and considered a wide range of initial values for the dispersion, , and the mean value, hlogMi. We have studied in detail the dependence on the initial conditions of the final values of , hlogMi, of the fraction of the initial number of clusters surviving after one Hubble time, and of the difference between the properties of the GCMF of clusters closer to the Galactic center and the properties of those located in the outer regions of the Galaxy. In most of the cases considered evolutionary processes alter significantly the initial population of globular clusters and the disruption of a significant number of globular clusters leads to a flattening in the spatial distribution of clusters in the central regions of the Galaxy. The initial log-normal shape of the GCMF is preserved in most cases and if a power-law in M is adopted for the initial GCMF, evolutionary processes tend to modify it into a log-normal GCMF. The difference between initial and final values of σ and (log M) as well as the difference between the final values of these parameters for inner and outer clusters can be positive or negative depending on initial conditions. A significant effect of evolutionary processes does not necessarily give rise to a strong trend of hlogMi with the galactocentric distance. The existence of a particular initial GCMF able to keep its initial shape and parameters unaltered during the entire evolution through a subtle balance between disruption of clusters and evolution of the masses of those which survive, suggested in Vesperini (1997), is confirmed.

Comments

This paper was harvested from ArXiv.org and ArXiv identifier is arXiv:9805308v1

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