Chemical evolution history of MaNGA galaxies

TL;DR

This study uses spectral synthesis to analyze the chemical enrichment history of MaNGA galaxies, revealing how mass, morphology, and star-forming status influence their metallicity evolution and gradients over cosmic time.

Contribution

It provides new insights into the interplay of mass, morphology, and star formation in galaxy chemical evolution using a comprehensive spectral synthesis analysis of MaNGA data.

Findings

Massive galaxies enriched earlier than less massive ones.

The mass-metallicity relation becomes shallower over time.

Metallicity gradients were inverted in low-mass galaxies in the past.

Abstract

We show the results of a study using the spectral synthesis technique study for the full MaNGA sample showing their Chemical Enrichment History (ChEH) as well as the evolution of the stellar mass-metallicity relation (MZR) over cosmic time. We find that the more massive galaxies became enriched first and the lower mass galaxies did so later, producing a change in the MZR which becomes shallower in time. Separating the sample into morphology and star-forming status bins some particularly interesting results appear: The mass dependency of the MZR becomes less relevant for later morphological types, to the extent that it inverts for Sd/Irr galaxies, suggesting that morphology is at least as important a factor as mass in chemical evolution. The MZR for the full sample shows a flattening at the high-mass end and another at the low-mass range, but the former only appears for retired galaxies while the latter only appears for star-forming galaxies. We also find that the average metallicity gradient is currently negative for all mass bins but for low mass galaxies it was inverted at some point in the past, before which all galaxies had a positive gradient. We also compare how diverse the ChEHs are in the different bins considered as well as what primarily drives the diversity: How much galaxies become enriched or how quickly they do so.