Evolution of the chemical enrichment and the Mass-Metallicity relation in CALIFA galaxies

TL;DR

This study uses fossil record techniques on CALIFA galaxies to analyze their chemical evolution and the mass-metallicity relation over time, revealing how morphology and star formation influence enrichment processes.

Contribution

It provides new insights into how galaxy morphology and star formation affect chemical enrichment and the evolution of the mass-metallicity relation in local universe galaxies.

Findings

Massive galaxies enriched faster historically.

Morphology influences enrichment speed more than mass.

Star-forming galaxies' metallicity converges over time.

Abstract

We use fossil record techniques on the CALIFA sample to study how galaxies in the local universe have evolved in terms of their chemical content. We show how the metallicity and the mass-metallicity relation (MZR) evolve through time for the galaxies in our sample and how this evolution varies when we divide them based on their mass, morphology and star-forming status. We also check the impact of measuring the metallicity at the centre or the outskirts. We find the expected results that the most massive galaxies got enriched faster, with the MZR getting steeper at higher redshifts. However, once we separate the galaxies into morphology bins this behaviour is not as clear, which suggests that morphology is a primary factor to determine how fast a galaxy gets enriched, with mass determining the amount of enrichment. We also find that star-forming galaxies appear to be converging in their chemical evolution, that is, the metallicity of star-forming galaxies of different mass is very similar at recent times compared to several Gyr ago.