Analysis of metallicity effects in SPH cosmological simulations

We report preliminar results on a chemical model implemented in a hydrodynamical cosmological code. We compute the metallicity of the gaseous component in galactic halos at different redshifts. The results compare reasonably well to observations. In particular, we show the predicted metallicity content of today-galaxy progenitors as a function of redshift and confront them with those observed in DLA systems.