Stellar population gradients from cosmological simulations: dependence on mass and environment in local galaxies

TL;DR

This study uses cosmological simulations to analyze how stellar age and metallicity gradients in local galaxies depend on mass and environment, revealing distinct patterns for dwarfs and massive systems.

Contribution

It provides new insights into the dependence of stellar population gradients on galaxy mass and environment using detailed cosmological simulations.

Findings

Dwarf galaxies show mostly zero age gradients with some positive outliers.

Massive galaxies tend to have zero or positive age gradients and steeper negative metallicity gradients.

Fossil groups exhibit tighter distributions of age and metallicity gradients.

Abstract

The age and metallicity gradients for a sample of group and cluster galaxies from N-body+hydrodynamical simulation are analyzed in terms of galaxy stellar mass. Dwarf galaxies show null age gradient with a tail of high and positive values for systems in groups and cluster outskirts. Massive systems have generally zero age gradients which turn to positive for the most massive ones. Metallicity gradients are distributed around zero in dwarf galaxies and become more negative with mass; massive galaxies have steeper negative metallicity gradients, but the trend flatten with mass. In particular, fossil groups are characterized by a tighter distribution of both age and metallicity gradients. We find a good agreement with both local observations and independent simulations. The results are also discussed in terms of the central age and metallicity, as well as the total colour, specific star formation and velocity dispersion.