Seminar: Outflow vs. Infall: The Origin of Extended MgII Halos

Dr Glenn Kacprzak 

Swinburne CAS

Download the pdf poster.

Quasar absorption line studies enable cool circumgalactic gas to be probed over a wide range of redshifts, in a fashion that is complementary to forthcoming HI and metal-line emission surveys. Ions such as MgII probe a large range of hydrogen column densities, from 17 - log[N(HI)] - 22, and thus also uniquely opens a window on the most diffuse gas in galaxy halos, unveiling structure at large galactocentric radii. By directing comparing the host galaxy properties (i.e.,colours, star-formation rates, morphologies, metallicities, kinematics) to those of the MgII absorption, we have begun to gain an understanding of the dynamical and chemical enrichment processes within galaxy halos. In this talk, I will review the current status of the origins of MgII gas, presenting strong cases for both infall and outflow models and over which MgII equivalent width regime each dominate.