SHAO Astrophysics Colloquium

Title: Make it, Shake it, Bake it: Warm Gas in the Circumgalactic Medium 

Speaker: S. Peng Oh (Univ of California, Santa Barbara)

Time: 3 pm, April 19 (Thursday)

Location: Lecture Hall, 3rd floor

Abstract: Warm photonized gas in the halos surrounding galaxies can be observed via quasar spectroscopy. They serve as our main window into the circumgalactic medium surrounding galaxies, serving as important indicators of star formation fueling (infall) and star formation feedback processes (outflow). Yet, the origin and survival of this gas is poorly understood. I discuss the possible origin of this gas via thermal instability, its puzzling survival despite strong hydrodynamic instabilities which should tear it apart, and the influence of non-thermal processes such as magnetic fields and cosmic rays. I also discuss the small scale structure of this gas and how it can be probed by Ly-alpha radiative transfer.