Chemical evolution models for local group dwarf spheroidal galaxies: the evolution of Fe-peak elements

The evolution of Fe-peak elements of several Local Group Dwarf Spheroidal Galaxies are discussed based on the comparison between a chemical evolution model and obsevations. In our scenario, the evolution of these galaxies are mainly controlled by a low star formation efficiency coupled with very intense galactic winds. The low star formation rate gives rise to the observed low metallicities and to [alpha/Fe] and [s/Fe] ratios below solar, whereas the intense galactic winds are responsible for the sharp decrease observed in several abundance ratios. The shape of the stellar metallicity distributions are defined by both parameters and the observed data cannot be reproduced without evoking galactic winds. The same scenario applied to a standard model fits very well several Fe-peak elements, with different nucleosynthesis prescriptions for each set of elements.