1999/01/18 by D. Thomas · 6 citations
Physics and Astronomy · #Astronomy and Astrophysical Research #Galaxies: Formation, Evolution, Phenomena #Stellar, planetary, and galactic studies #astro-ph
paper · pdf · doi:10.1046/j.1365-8711.1999.02552.x
published as Mon.Not.Roy.Astron.Soc.306:655,1999 · 7 pages, 3 figures, accepted by MNRAS
arxiv created 1999/01/18 · openalex publication_date 1999/07/01 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/30
The chemical enrichment and stellar abundance ratios of galaxies that 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 by Kauffmann. It turns out that the average SFH of cluster ellipticals does not yield globally α-enhanced stellar populations. The starburst that occurs when the elliptical forms in the major merger therefore plays a crucial role in producing α-enhancement. Only under the assumption that the initial mass function is significantly flattened with respect to the Salpeter value during the burst, can a Mg/Fe overabundant population be obtained. In particular, for the interpretations of radial gradients in metallicity and α-enhancement, the mixing of global and burst populations are of great importance. The model predicts bright field galaxies to be less α-enhanced than their counterparts in clusters.