Title: The Hidden Baryons of the Milky Way

Speaker: Dr. Yong Zheng (郑永), UC Berkeley

Host: Taotao Fang

Time: 14:30-16:30, Thursday, Dec 26, 2019

Location: Physics Building 552

Abstract: Galaxies are not lonely islands floating in the Universe. They host large gaseous envelopes of baryons, a.k.a., the circum-galactic medium (CGM), that exist far beyond a galaxy’s visible extent. Baryonic inflows from CGM replenish star-forming fuel in galaxies, whereas outflows from galaxies enrich the CGM. In this talk, I will describe the theoretical and observed distribution and flows of baryons in the CGM of our own Milky Way (MW), including how the MW’s disk hides up to half of its CGM from direct observation. I will then describe new techniques to generate synthetic observations of the CGM using the Enzo & FOGGIE cosmological simulations, and show how these can be used to reveal the hidden baryons in the MW’s CGM. Finally, I will briefly highlight the connections between low- and high-redshift CGM studies, including new applications that rely on fast radio bursts (FRBs).