Probing Gas Halos of Galaxies with SDSS

Event Date: 

Wednesday, January 16, 2013 - 4:00pm

Event Location: 

  • Broida Conference Room 3302

Astro Seminar


Guangtun Ben Zhu (JHU)

The distribution of gas around galaxies – the circumgalactic and intergalactic media – contains signatures of key processes of galaxy formation such as out?ows and accretion, and may account for the majority of baryons in the Universe. Absorption-line spectroscopy is a powerful tool to probe gas properties. SDSS has obtained spectroscopy for ~200,000 quasars, providing a perfect dataset for statistical analyses of absorption lines. I will introduce the new techniques we have developed to model quasar spectra and detect absorption lines. With these new tools, we have compiled a metal absorber catalog of ~50,000 systems. I will present a statistical analysis of these absorber systems and discuss implications for gas flow processes. In addition, our results allow us to measure the Galaxy-Gas correlation out to Mpc scales, linking the gas properties of individual galaxies to their large-scale environment.