Alpha-element enhancement in a lambda-CDM Universe

GARGIULO, IGNACIO D.; MUÑOZ ARANCIBIA, ALEJANDRA M.; CORA, SOFÍA A.; PADILLA, NELSON D.

San Juan

Workshop; 54ª Reunión Anual de la Asociación Argentina de Astronomía; 2011

We study the chemical enrichment of elliptical galaxies using a semi-analytic model of galaxy formation combined with a cosmological N-body simula- tion of dark matter particles. In particular, we study the a-element abun- dances with respect to the iron content of galaxies. The main modification to the previous models (Cora 2006; Lagos et al. 2008; Tecce et al. 2010) was the implementation of a top heavy variable initial mass function with a theoretical basis (Weidner & Kroupa 2004, 2005, 2006; Weidner et al. 2011). We find that with a single initial mass function at all epochs the observed trend of [a/Fe] with the stellar mass of elliptical galaxies can be hardly reproduced. We propound that a top heavy integrated galactic mass function can be a plausible solution for this problem.FULL TEXT IN SPANISH