A quantitative demonstration that stellar feedback locally regulates galaxy growth

TL;DR

This study uses spatially resolved spectroscopy to measure how local stellar feedback regulates galaxy growth, finding that feedback efficiency depends on local stellar mass density and matches simulation predictions.

Contribution

It introduces a novel method to derive local and global mass-loading factors from spectroscopic data, linking stellar feedback to galaxy properties and validating simulation models.

Findings

Local mass-loading factors depend on stellar mass surface density.

Global mass-loading factors agree with hydrodynamical simulations.

Method provides a new way to test stellar feedback models.

Abstract

We have applied stellar population synthesis to 500 pc sized regions in a sample of 102 galaxy discs observed with the MUSE spectrograph. We derived the star formation history and analyse specifically the "recent" ($20\rm{Myr}$) and "past" ($570\rm{Myr}$) age bins. Using a star formation self-regulator model we can derive local mass-loading factors, $\eta$ for specific regions, and find that this factor depends on the local stellar mass surface density, $\Sigma_*$, in agreement with the predictions form hydrodynamical simulations including supernova feedback. We integrate the local $\eta$-$\Sigma_*$ relation using the stellar mass surface density profiles from the Spitzer Survey of Stellar Structure in Galaxies (S4G) to derive global mass-loading factors, $\eta_{\rm{G}}$, as a function of stellar mass, $M_*$. The $\eta_{\rm{G}}$-$M_*$ relation found is in very good agreement with hydrodynamical cosmological zoom-in galaxy simulations. The method developed here offers a powerful way of testing different implementations of stellar feedback, to check on how realistic are their predictions.