A continuum of environmental influence on the circumgalactic medium

The circumgalactic medium (CGM) serves as a massive, multiphase baryon reservoir and mediates all accretion and outflow from a galaxy.  Hence, the continuation of star formation in the galaxy as well as the metal enrichment of the intergalactic medium and the host galaxy critically depend on the composition and physical conditions of the CGM.  Furthermore, any galaxy interactions one with another or with their ambient environment, i.e., the intracluster or intragroup medium, are first felt by the CGM.  From HST/COS absorption line spectroscopy and EAGLE zoom-in simulations, I will demonstrate that the CGM exhibits a continuum of influence from underdense field environments to groups to galaxy clusters.  The absorption line data provide a unique means by which to study the far reaches of galaxy cluster outskirts and the physical conditions in the large scale structures that feed them, lending critical insight to galaxies’ transformation due to their environment.

Speaker: Joe Burchett, UC Santa Cruz