Quasar Absorption Lines: From Reionization to Dark Matter

George Becker, Dept. of Physics & Astronomy, UC-Riverside

Absorption patterns in the spectra of distant quasars are one of our most powerful probes of cosmic structure. The rich “forest” of lines produced by hydrogen encodes the evolution of intergalactic structure over more than 90% of cosmic history. Meanwhile, absorption signatures from elements such carbon and oxygen trace the dynamic assembly of galaxies.

I will present new insights from quasar absorption lines into two outstanding issues: (1) how and when was the Universe (re-)ionized by the first galaxies? and (2) how cold (or warm) is dark matter? These projects combine data from the largest optical telescopes with advanced numerical simulations, and suggest new approaches to studying the distant Universe.