Chemical Evolution in Hierarchical Clustering Scenarios

We present first results of an implementation of chemical evolution in a cosmological hydrodynamical code, focusing the analysis on the effects of cooling baryons according to their metallicity. We found that simulations with primordial cooling can underestimate the star formation rate from $z < 3$ and by up to $\approx 20 %$. We constructed simulated spectra by combining the star formation and chemical history of galactic systems with spectra synthesis models and assess the impact of chemical evolution on the energy distribution.