Dr. Chris Churchill
New Mexico State University

University of Florida Astronomy Colloquium - Nov 16th, 2005

Gas Kinematics - Galaxy Morphology Connection at 0.4 < z < 1.0

The role of gas in the vicinity of galaxies is a key ingredient for constraining models and scenarios of galaxy formation and evolution. The current status and remaining questions of galaxies hosting MgII absorption are reviewed with an eye toward new results incorporating high quality Hubble Space Telescope images of the absorbing galaxies. First, we find that our decade established picture of extended gaseous regions around galaxies at earlier epochs is in need of significant revision; MgII absorbing ``halos'' appear to be patchier and their geometry less regular than previously inferred. We also find that the so-called "weak" MgII absorbers are associated with normal galaxies over a wide range of impact parameters, suggesting that this class of absorber does not, as previously suggested, strictly select low surface brightness, dwarf galaxies, or IGM material. Second, we have quantified the morphology of the galaxies and discovered a correlation between galaxy "asymmetries" and MgII absorption strengths. Incorporating both results, we suggest a connection between past minor events that perturb the visible galaxy and the quantity and dynamics of the gas in the proximity of galaxies.