The evolution of the radial gradient of Oxygen abundance in spiral galaxies

TL;DR

This study models the chemical evolution of spiral galaxies to understand how the radial oxygen abundance gradient develops and varies with galaxy properties, star formation, and cosmic time.

Contribution

It introduces new chemical evolution models that analyze the impact of infall rate and star formation history on oxygen gradients across galaxy types.

Findings

Radial oxygen gradient is mainly a scale effect, stable over time within the optical radius.

Normalized radial gradients are similar across galaxy masses, indicating a universal gradient.

Differences in star formation efficiency cause dispersion around the average gradient.

Abstract

The aim of this work is to present our new series of chemical evolution models computed for spiral and low mass galaxies of different total masses and star formation efficiencies. We analyze the results of models, in particular the evolution of the radial gradient of oxygen abundance. Furthermore, we study the role of the infall rate and of the star formation history on the variations of this radial gradient. The relations between the O/H radial gradient and other spiral galaxies characteristics as the size or the stellar mass are also shown. We find that the radial gradient is mainly a scale effect which basically does not change with the redshift (or time) if it is measured within the optical radius. Moreover, when it is measured as a function of a normalized radius, show a similar value for all galaxies masses, showing a correlation with a dispersion around an average value which is due to the differences star formation efficiencies, in agreement with the idea of an universal O/H radial gradient