Chemical evolution of local group dwarf spheroidal galaxies

"The chemical evolution of six local group dwarf spheroidal Galaxies is discussed based on studies performed with an one-zone chemical evolution model which is able to reproduce the main observational constraints of these galaxies. Several abundance ratios, the total mass, the gas mass and the metallicity distribution predicted by such models t the observed data very well. In our scenario, the evolution of the dSphs is mainly controlled by a low star formation rate and by very intense galactic winds. The low star formation in these galaxies gives rise to the observed low metallicities, whereas the intense galactic winds are responsible for the low nalgas mass and for the sharp decrease observed in the abundance ratios. Besides that, both parameters help in dening the shape of the stellar metallicity distributions, in agreement with observations."