ASTRONOMY COLLOQUIUM /Spring 2007

February 14

Prof. Elizabeth Barton

University of California at Irvine

Understanding Galaxy Interactions

New, large-volume cosmological simulations accurately describe the spatial distribution of galaxies in the universe. We are now in an era where the simulations can be used to inform observational studies of the physical processes that happen in galaxy evolution, such as galaxy interactions. Using cosmological simulations as a guide, my collaborators and I have explored the nature of galaxy pairs selected from a redshift survey, using the technique to make the first clean measurement of the frequency and strength of triggered star formation in isolated galaxy interactions. We are also using the simulated orbits of galaxies in pairs to further understand the signatures of merging and the relationships between merging and the close pair fraction. The ultimate goal of this research is to differentiate the effects of low-speed galaxy interactions and mergers from all other environmental processes, thus revealing the origin of the well-known morphology-density relation.