Connecting Star Formation and Stellar Feedback in Galaxies
Matthew Orr (CCA, Flatiron Institute)
April 10, 2023
Abstract: Understanding how the highly turbulent gas in galaxies forms stellar populations is critical to understanding the evolution of gaseous galactic ecosystems, a key focus of the 2020 decadal survey. In this seminar, I will present recent results from the FIRE simulations, among the first simulations to resolve a multiphase ISM and include meaningful feedback physics (e.g., supernovae and stellar winds). I will demonstrate how the FIRE simulations are ideal tools for studying the relationship between star formation and turbulence in galaxies. This talk will explore the emergence of scaling relations like the spatially resolved Kennicutt-Schmidt relation (relating the local gas reservoir to the rate of star formation) and connections between gas turbulence (velocity dispersions/line widths) and star formation rates. I will show how highly efficient local star formation translates to low global star formation efficiency, with the addition of stellar feedback. Additionally, I will lay out conceptual models I have developed to interpret observations and these simulations, from time-delayed feedback driving cyclic star formation episodes, to the importance of clustered supernovae in blowing superbubbles in the ISM of galaxies and as drivers of galactic superwinds. These models give us insight as to where and why stellar feedback injects momentum into the ISM versus the near-CGM, and has strong implications for the formation of galactic disks near z ~ 1.