Spatially resolved mass-metallicity relation at z~0.26 from the MUSE-Wide Survey

Abstract

Aims. There is a spatially resolved star-forming main sequence (rSFMS) and mass-metallicity relation (rMZR) of galaxies in local universe. We know that the global mass-metallicity relation (MZR) results from the integral of rMZR, and it will evolve with the redshift. However, the evolution of rMZR with redshift is still unclear due to the low spatial resolution and signal-to-noise ratio. There are currently too few observations beyond local universe, and only simulations can reproduce the evolution of rMZR with redshift. Methods. In this work, we select ten emission-line galaxies with an average redshift of z ∼ 0.26 from MUSE-Wide DR1. We obtain the spatially resolved star formation rate (SFR) and metallicity from the integral field spectroscopy (IFS), as well as the stellar mass surface density from the 3D-HST photometry. We derive the rSFMS and rMZR at z ∼ 0.26 and compare them with local galaxies. Results. We find the rSFMS of galaxies at z ∼ 0.26 has a slope of ∼0.771. The rMZR exists at z ∼ 0.26, showing a similar shape to the local universe but a lower average metallicity about ∼0.11 dex than the local one. In addition, we also study their spatially resolved fundamental metallicity relation (rFMR). However, there is no obvious evidence that rFMR exists at z ∼0.26 and it is not an extension of rMZR at a high SFR. Conclusions. Similar to their global versions, the rSFMS and rMZR of galaxies also evolve with redshift. Given the fixed stellar mass, galaxies at higher redshift show higher SFR and lower metallicity. These suggest that the evolution of the global galaxy properties with redshift may result from integrating the evolution of spatially resolved properties of galaxies.