BCCP Seminars

Tuesday, September 23
Location: UCB Hearst Field Annex B-1 – 1:10 pm
Speaker: Joe Hennawi, MPIA
Title: “Three Unresolved Problems in Studies of the Circumgalactic Medium”
Abstract: The physical conditions of diffuse gas in the outskirts of galaxies, known as the circumgalactic medium, regulates the supply of fuel for star-formation in galaxies. The conventional wisdom is that hydrodynamics of this moderate overdensity gas is resolved by current simulations of galaxy formation. I will present three different observations suggesting that the observed properties of the circumgalactic medium are in conflict with the predictions of these simulations, casting serious doubts on the predictive power of the current generation of models. While the galaxy formation community has focused a tremendous amount of effort on sub-grid prescriptions to describe unresolved processes like star-formation and feedback, I will argue that because the circumgalactic medium sets the initial conditions for galaxy formation,  resolving these discrepancies likely poses a more pressing problem.