The metallicity properties of zCOSMOS galaxies at 0.2<z<0.8

TL;DR

This study investigates the metallicity-stellar mass-SFR relation in galaxies from zCOSMOS between redshifts 0.2 and 0.8, confirming the non-evolution of the Fundamental Metallicity Relation over this period.

Contribution

It extends the analysis of the Fundamental Metallicity Relation to higher redshifts up to 0.8, providing stronger evidence for its invariance over the last half of cosmic history.

Findings

Metallicity depends on stellar mass and SFR at z<0.46.

No evidence of evolution in the FMR from 0.2 to 0.8.

Metallicity scatter around the relation is about 0.16 dex.

Abstract

We study the metallicity properties of galaxies in the zCOSMOS sample between 0.2<z<0.8. At z<0.46, where Ha and [NII] are detected, we find the same dependence of metallicity on stellar mass and Star Formation Rate (SFR), the Fundamental Metallicity Relation, found by Mannucci et al. (2010) in SDSS galaxies on a similar redshift range. We extend this relation to higher redshift, 0.49<z<0.8 where the R23 metallicity index can be measured in our data, finding no evidence for evolution, and a metallicity scatter around the relation of about 0.16 dex. This result confirms, with a much higher level of significance with respect to previous works, the absence of evolution of the FMR during the last half of cosmic history.