Abundance ratios in hierarchical galaxy formation
Abstract
The chemical enrichment and stellar abundance ratios of galaxies which form in a hierarchical clustering scheme are calculated. For this purpose I adopt the star formation histories (SFH) as they are delivered by semi-analytic models in Kauffmann (1996}. It turns out that the average SFH of cluster ellipticals does not yield globally alpha-enhanced stellar populations. The star burst that occurs when the elliptical forms in the major merger plays therefore a crucial role in producing alpha-enhancement. Only under the assumption that the IMF is significantly flattened with respect to the Salpeter value during the burst, a Mg/Fe overabundant population can be obtained. In particular for the interpretation of radial gradients in metallicity and alpha-enhancement, the mixing of global and burst populations are of great importance. The model predicts bright field galaxies to be less alpha-enhanced than their counterparts in clusters.
Keywords
Cite
@article{arxiv.astro-ph/9901226,
title = {Abundance ratios in hierarchical galaxy formation},
author = {D. Thomas},
journal= {arXiv preprint arXiv:astro-ph/9901226},
year = {2009}
}
Comments
7 pages, 3 figures, accepted by MNRAS