LSD and AMAZE: the mass-metallicity relation at z>3

TL;DR

This paper presents the first measurement of the galaxy mass-metallicity relation at redshifts greater than 3, revealing significant evolution and challenging simple outflow models of galaxy evolution.

Contribution

It provides the first observational estimate of the mass-metallicity relation at z>3 using near-infrared spectroscopy of Lyman-break galaxies.

Findings

Strong evolution of the mass-metallicity relation from z=0 and z=2 to z=3.

Effective oxygen yields do not increase with stellar mass at z>3.

Simple outflow models are inconsistent with the observed metallicity trends.

Abstract

We present the first results on galaxy metallicity evolution at z>3 from two projects, LSD (Lyman-break galaxies Stellar populations and Dynamics) and AMAZE (Assessing the Mass Abundance redshift Evolution). These projects use deep near-infrared spectroscopic observations of a sample of ~40 LBGs to estimate the gas-phase metallicity from the emission lines. We derive the mass-metallicity relation at z$>$3 and compare it with the same relation at lower redshift. Strong evolution from z=0 and z=2 to z=3 is observed, and this finding puts strong constrains on the models of galaxy evolution. These preliminary results show that the effective oxygen yields does not increase with stellar mass, implying that the simple outflow model does not apply at z>3.