Speaker
Prof.
Varsha Kulkarni
(University of South Carolina)
Description
Quasar absorption lines offer powerful probes to study the circumgalactic medium and the intergalactic medium. The gas-rich damped Lyα (DLA) and sub-DLA absorbers allow an especially detailed study of metals, gas, and dust in the circum-galactic medium. Most past studies of chemical composition of the absorbers focused on DLAs, rather than sub-DLAs. But recent studies by our team and others have indicated that at redshifts 0.6 < z < 1.5, sub-DLAs may be more metal-rich than DLAs, and may have evolved faster. We will discuss our new Magellan and HST spectroscopic observations of sub-damped Lyα absorbers at z > 2 as well as z < 0.6, and the implications for cosmic chemical evolution models. We will also discuss results obtained from imaging and/or integral field spectroscopy of some DLA/sub-DLAs to investigate the gas kinematics and spatial distribution of metals in the circumgalactic medium in these distant galaxies.
