Seminar by Cameron Trapp, UC San Diego
Observations indicate that a continuous supply of gas is needed to maintain observed star formation rates in large, disky galaxies. To fuel star formation, gas must reach the inner regions of such galaxies. Despite its crucial importance for galaxy evolution, how and where gas joins galaxies is poorly constrained observationally and rarely explored in fully cosmological simulations. I will discuss the results of our initial study investigating gas accretion and transport in the FIRE-2 cosmological zoom-in simulations for 4 Milky Way mass galaxies. We generally found that gas joins just interior to the disk edge before radially transporting through the disk at average speeds of 1-5 km/s. This corresponds to radial mass fluxes of a couple solar masses per year, comparable to the galaxies’ star formation rates. I will also discuss more recent work focused on understanding the angular momentum transfer required for these gas flows, including terms from gravitational torques, MHD torques, and torques from stellar feedback. Finally, while we find overall consistency of our results with observational constraints, more detailed comparisons are needed. I will discuss our recent work creating synthetic HI observations of these galaxies for more direct observational comparisons, including Tilted ring fitting and a novel utilization of Convolutional Neural Networks to infer radial mass flux profiles.
Host: Jingyao Zhu