ERC 161 ERC 161
Cold Gas in Hot Halos: The Formation and Survival of Cold Gas in Galactic Halos
In recent years, observations of the circumgalactic medium has undercovered a large reservoir of T ~ 10^4 K, photoionized gas in the much hotter halos of galaxies. Inflowing cold gas in galactic halos helps fuel star formation, whilst outflowing cold gas is our primary observational marker of feedback. However, the formation and survival of dense cold gas in the atmospheres of galaxy halos is still poorly understood. For instance, we do not yet understand how cold gas can be entrained in a hot wind, as is observed; most simulations indicate it should be shredded by hydrodynamic instabilities. The small scale structure of the cold gas is also poorly understood; galaxy formation simulations show CGM properties which are not converged numerically, and it is not clear what scales need to be resolved to achieve convergence. In this talk I will highlight some recent progress on these questions.