Star Formation Histories of Southern Compact Groups

Compact group galaxies are a common phase in galaxy evolution and provide insight into the process that transforms galaxies from isolated, star forming late-type galaxies to passive galaxies in high density environments. I mapped spectrally the central and middle regions of 40 galaxies in 10 Southern Compact Groups and established group membership by redshift. Of the eight groups with all members observed, I found that one galaxy is not in the group in four cases. I obtained ages and metallicities of the stellar populations using the STARLIGHT code to summarize past star formation and current activity. Galaxies that are part of a group showed both high-metallicity stellar populations, indicating rapid processing of gas through multiple star formation episodes, and low-metallicity star formation. Thus, Southern Compact Group galaxies have a wide range of stellar population properties, indicating that these groups are in different stages of evolution.Doctor of Philosoph