04 February 2024Séminaire – Noé Brucy (University of Heidelberg)

Regulation of star formation in disk galaxies: the role of large-scale turbulence

The conversion of gas into stars is a slow and inefficient process, and the observed star formation rates are two orders of magnitude below what would be predicted by a gravity-only model. However, what regulates the star formation rate is still an open question, as a unified theory that allows us to understand the condensation of the gas at all relevant scales is still lacking. In this talk I will present numerical simulations at the kiloparsec and galactic scales to identify the main processes responsible for slowing down star formation. We will see that stellar feedback is only effective when the surface density of the gas is low enough. For gas-rich galaxies, galactic-scale turbulence is required to reproduce the observed star formation rates. We will then explore the implications for existing analytical models of the star formation rate and discuss how large-scale turbulence can be quantified.