The dependence of the mass-metallicity relation on large-scale environment
Journal
Monthly Notices of the Royal Astronomical Society
Journal Volume
468
Journal Issue
2
Pages
1881-1892
Date Issued
2017
Author(s)
Abstract
We examine the relation between gas-phase oxygen abundance and stellar mass-the MZ relation-as a function of the large-scale galaxy environment parametrized by the local density. The dependence of the MZ relation on the environment is small. The metallicity where the MZ relation saturates and the slope of the MZ relation are both independent of the local density. The impact of the large-scale environment is completely parametrized by the anticorrelation between local density and the turnover stellar mass where the MZ relation begins to saturate. Analytical modelling suggests that the anticorrelation between the local density and turnover stellar mass is a consequence of a variation in the gas content of star-forming galaxies. Across ~1 order of magnitude in local density, the gas content at a fixed stellar mass varies by ~5 per cent. Variation of the specific star formation rate with the environment is consistent with this interpretation. At a fixed stellar mass, galaxies in lowdensity environments have lower metallicities because they are slightly more gas-rich than galaxies in high-density environments. Modelling the shape of the mass-metallicity relation thus provides an indirect means to probe subtle variations in the gas content of star-forming galaxies. © 2017 The Authors.
Subjects
Galaxies: abundances; Galaxies: evolution; Galaxies: ISM
Other Subjects
Astrophysics; Density of gases; Gases; Metals; Stars; Anticorrelation; Galaxies abundances; Galaxies: ISM; Galaxy evolution; Gas content; Large-scales; Local-density; Metallicities; Star forming galaxy; Stellar mass; Galaxies
Type
journal article