Empirical Constraints for the Magnitude and Composition of Galactic Winds

TL;DR

This paper uses empirical data on oxygen deficits in star-forming galaxies to constrain the magnitude and composition of galactic winds, providing a new parameterization for galaxy evolution models.

Contribution

It introduces a novel empirical approach to quantify metal outflows and reaccretion, integrating these into a single effective metal loading factor based on galaxy virial velocity.

Findings

Derived an effective metal loading factor as a function of virial velocity.

Provided a parameterization that can be incorporated into galaxy evolution models.

Highlighted the importance of metal reaccretion in galactic wind modeling.

Abstract

Galactic winds are a key physical mechanism for understanding galaxy formation and evolution, yet empirical and theoretical constraints for the character of winds are limited and discrepant. Recent empirical models find that local star-forming galaxies have a deficit of oxygen that scales with galaxy stellar mass. The oxygen deficit provides unique empirical constraints on the magnitude of mass loss, composition of outflowing material and metal reaccretion onto galaxies. We formulate the oxygen deficit constraints so they may be easily implemented into theoretical models of galaxy evolution. We parameterize an effective metal loading factor which combines the uncertainties of metal outflows and metal reaccretion into a single function of galaxy virial velocity. We determine the effective metal loading factor by forward-fitting the oxygen deficit. The effective metal loading factor we derive has important implications for the implementation of mass loss in models of galaxy evolution.