AAS Meeting #194 - Chicago, Illinois, May/June 1999
Session 12. Extra Galactic Star Clusters: From Ancient Globulars to Young Star Clusters
Display, Monday, May 31, 1999, 9:20am-6:30pm, Southwest Exhibit Hall

[Previous] | [Session 12] | [Next]


[12.06] Evolution of the mass function of the Galactic globular cluster system

E. Vesperini (U. of Massachusetts-Amherst)

I show the results of a detailed investigation of the evolution of the mass function of the Galactic globular cluster system (GCMF). The effects of stellar evolution, two-body relaxation, disk shocking and dynamical friction on the evolution of individual globular clusters have been considered. I have adopted a log-normal initial GCMF and I have studied the dependence on the initial dispersion and mean value of the GCMF of the final GCMF, 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 of those in the outer 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. A significant effect of evolutionary processes does not necessarily give rise to a strong trend of the mean value of the GCMF 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.


If the author provided an email address or URL for general inquiries, it is a s follows:

vesperin@falcon.phast.umass.edu

[Previous] | [Session 12] | [Next]