Speaker: Chris Carr
Coupling & Collisions: The Dynamic Lives of Galactic Atmospheres
The circumgalactic medium (CGM) is a vast multiphase atmosphere of gas bound to the halos of galaxies that lies at the nexus of inflowing gas from the cosmic web, swarming satellites, and outflows from the central galaxy. How exactly these diverse processes couple to the thermal & kinetic properties of the CGM and in turn how that shapes the properties of the galaxies they surround, remains a missing chapter in the story of galaxy formation. In this talk, I will first present a new simplified, 1D-analytic model to study the key processes governing star formation in galaxies and their impact on the mass, energy, and metal contents of their galactic atmospheres. With an emphasis on the stellar-to-halo mass relation, our model shows that we can regulate star formation in low-mass systems with galactic wind properties that are motivated by observations and high-resolution simulations of supernova winds in the multiphase interstellar medium and departs from the traditional thinking on how feedback in low-mass galaxies suppresses star formation. Secondly, I will extend the question of CGM physics to the domain of interacting galaxies and introduce my suite of simulations of a Milky Way-like CGM with an infalling satellite like our own Large Magellanic Cloud (LMC). The infall of such massive satellites, which may harbor CGM gas of their own, could be sourcing large-scale disruptions in the CGM of their host galaxies. I will then end with a discussion on how the signatures of the ongoing interaction with the LMC could manifest in the observable properties of our Galaxy's CGM.
