Merger Induced Globular Cluster Formation and Galaxy Evolution

Abstract

Based on the earlier work of Gunn and McCrea we model the formation of globular clusters in merging galaxies. Neutral hydrogen observations of dwarf irregular galaxies as well as more luminous systems are used to provide the key parameters of the model. The observations indicate that clusters with the mass of globular clusters should still be forming today. The model is incorporated into a phenomenological picture of galaxy evolution making use of a simple chemical evolution model. These results are compared to recent observations of the metallicity distributions of F and G stars from a recent large SDSS survey. The comparisons are consistent with an anisotropic collapse and merging of a large number of dwarf irregular galaxies for the formation of the Galaxy.Comment: 17 pages including 6 figures-accepted for publication in the Astrophysical Journa