Properties of the outer regions of spiral disks: abundances, colors and ages

TL;DR

This paper uses chemical evolution models to analyze the radial distribution of abundances, ages, and metallicities in spiral galaxy disks, exploring the causes of abundance gradient flattening in outer regions.

Contribution

It introduces a comprehensive set of models for spiral disks that examine the impact of molecular gas formation on abundance gradient profiles.

Findings

Radial abundance profiles vary with galaxy mass and star formation efficiency.

Flattening of abundance gradients in outer disks may be linked to molecular gas formation processes.

Stellar ages and metallicities show distinct radial trends in the models.

Abstract

We summarize the results obtained from our suite of chemical evolution models for spiral disks, computed for different total masses and star formation efficiencies. Once the gas, stars and star formation radial distributions are reproduced, we analyze the Oxygen abundances radial profiles for gas and stars, in addition to stellar averaged ages and global metallicity. We examine scenarios for the potential origin of the apparent flattening of abundance gradients in the outskirts of disk galaxies, in particular the role of molecular gas formation prescriptions.