Friday, October 28, 2011, 3pm
Innovation Hall room 136

Jason Tumlinson
Space Telescope Science Institute

Gas and Metals in the Halos of Galaxies: The News from HST

In recent years we have come to appreciate the great importance of the gas just outside galaxies - the circumgalactic medium - to galaxy formation and evolution. I will briefly survey the intellectual history of this subject before presenting the latest results from two large Hubble projects that are using the new Cosmic Origins Spectrograph to systemically characterize the gaseous halos of low-redshift galaxies. COS has uncovered a clear link between star formation and ionized gas in gaseous halos beyond 100 kpc. Furthermore, we find that the gaseous halos of star-forming galaxies may contain more mass in metals than the interstellar medium of these same galaxies. I will discuss the importance of these results for the formation and evolution of galaxies in general.