Evolution of the Stellar Mass-Metallicity Relation. II. Constraints on Galactic Outflows from the Mg Abundances of Quiescent Galaxies

Evolution of the Stellar Mass-Metallicity Relation. II. Constraints on Galactic Outflows from the Mg Abundances of Quiescent GalaxiesLeethochawalit, NichaKirby, Evan N.Ellis, Richard S.Moran, Sean M.Treu, TommasoDOI: info:10.3847/1538-4357/ab4809v. 885100
Leethochawalit, Nicha, Kirby, Evan N., Ellis, Richard S., Moran, Sean M., and Treu, Tommaso. 2019. "Evolution of the Stellar Mass-Metallicity Relation. II. Constraints on Galactic Outflows from the Mg Abundances of Quiescent Galaxies." The Astrophysical Journal 885:100. https://doi.org/10.3847/1538-4357/ab4809
ID: 154615
Type: article
Authors: Leethochawalit, Nicha; Kirby, Evan N.; Ellis, Richard S.; Moran, Sean M.; Treu, Tommaso
Abstract: We present the stellar mass-[Fe/H] and mass-[Mg/H] relation of quiescent galaxies in two galaxy clusters at z ̃ 0.39 and z ̃ 0.54. We derive the age, [Fe/H], and [Mg/Fe] for each individual galaxy using a full- spectrum fitting technique. By comparing with the relations for z ̃ 0 Sloan Digital Sky Survey galaxies, we confirm our previous finding that the mass-[Fe/H] relation evolves with redshift. The mass-[Fe/H] relation at higher redshift has lower normalization and possibly steeper slope. However, based on our sample, the mass-[Mg/H] relation does not evolve over the observed redshift range. We use a simple analytic chemical evolution model to constrain the average outflow that these galaxies experience over their lifetime, via the calculation of mass-loading factor. We find that the average mass-loading factor η is a power-law function of galaxy stellar mass, η \propto {M}* -0.21+/- 0.09. The measured mass-loading factors are consistent with the results of other observational methods for outflow measurements and with the predictions where outflow is caused by star formation feedback in turbulent disks.