Should chemical abundance distributions of satellites look like their stellar halos?

Abstract

Observations suggest systematic differences between chemical abundances of stars in satellite galaxies and those in the Milky Way halo. These results are difficult to understand at present in the context of hierarchical structure formation, in which dwarf galaxies are believed to be the building blocks of galaxy formation. In this study, we model the accretion and disruption of dwarf galaxies in a ΛCDM Universe using, in combination, a semi-analytical code and numerical simulations. We conclude that differences between the accretion times of surviving satellites versus stars in the local halo, as well as the effect of feedback processes, may account for the observed differences in the chemical abundance distributions. © 2006 Springer-Verlag Berlin Heidelberg.