Le 13 juin 2014
De 10h30 à 12h00
Carsten WEIDNER
Instituto de Astrofísica de Canarias
Recent evidence based independently on spectral line strengths and dynamical modelling of massive early-type galaxies (ETG) point towards a non-universal stellar initial mass function (IMF), probably implying a bottom-heavy IMF, i.e. an excess of low-mass stars in ETGs with a high velocity dispersion. However, calculating chemical evolution models for ETGs with bottom-heavy IMFs shows that such steep IMFs are in conflict with the observed metal-rich populations found in ETGs as well as with the number of stellar remnants observed within these systems. A model is presented which satisfies these apparently conflicting observations together with other constraints, such as age, metallicity, alpha-enhancement, mass-to-light ratios or the mass fraction of the stellar component in low-mass stars.