Astronomy seminar via zoom: Cosmic gas flows in the circumgalactic medium around Milky Way-like galaxies

Galaxies are intimately connected to the environments they live in. The haloes around them contain the gas reservoir from which the galaxies grow, while galactic outflows heat and enrich this ‘circumgalactic medium’ (CGM). Using cosmological, magnetohydrodynamical simulation we will discuss¬†the physical and observable properties of the gas around galaxies. The simulations use a new simulation refinement technique to reach orders of magnitude higher resolution than the current state-of-the-art. These spatially refined simulations show that the CGM has more ‘cool’ gas than previously thought, which strongly affects predicted observables in the CGM: The neutral hydrogen (HI) column densities are dramatically enhanced, more in line with observations.¬†I will also show how the presence of magnetic fields alters the gas flows into and out of galaxies, resulting in less mixing and higher gas fractions inside the halo. I will briefly discuss the effects on the galaxies themselves.¬†