Alpha-element enhancement in a LCDM Universe

I. D. GARGIULO; A. M. MUÑOZ; S. A. CORA; N. D. PADILLA

San Juan

Congreso; LIV Reunión Anual de la Asociación Argentina de Astronomía; 2011

Asociación Argentina de Astronomía - Sociedad Chilena de Astronomía

We study the chemical enrichment of elliptical galaxies using a semianalyticmodel of galaxy formation combined with a cosmological N-body simulation of dark matter particles. In particular, we study the-element abundances with respect of the iron content of galaxies. Themain modification to the previous models (Cora 2006; Lagos et al. 2008;Tecce et al. 2010) was the implementation of a top heavy variable initialmass function with a theoretical basis (Weidner & Kroupa 2004, 2005,2006; Weidner et al. 2011). We find that with a single initial massfunction at all epochs the observed trend of [alpha/Fe] with the stellar massof elliptical galaxies can be hardly reproduced. We propound that a topheavy integrated galactic mass function can be a plausible solution forthis problem.