Long Ago when Galaxies were Young: Probing Galaxy Evolution with Quasar Absorption Lines

Varsha P. Kulkarni

University of South Carolina, Department of Physics and Astronomy, Columbia, SC 29208

One of the important goals of modern astrophysics is to understand how galaxies form and evolve and how the production of elements proceeds in young galaxies. A unique tool to investigate distant young galaxies is to study the absorption lines they produce when they intervene with the light from distant background quasars. Absorption-line spectroscopy of quasars allows us to empirically trace the progressive evolution of chemical composition of galaxies with time. Deep imaging of absorbers with the Hubble Space Telescope and ground-based facilites is also helping us to investigate how the morphology and star formation rates of the absorbers evolve with time. These observations are helping to clarify the absorber-galaxy connection, and shedding light on the evolution of normal galaxies over the past 80% of the age of the Universe.