Galactic chemical enrichment with new metallicity dependent yields

New detailed stellar yields of several elemental species are derived for massive stars in a wide range of masses (from 6 to 120 Msol) and metallicities (Z= 0.0004, 0.004, 0.008, 0.02, 0.05). Our calculations are based on the Padova evolutionary tracks and take into account recent results on stellar evolution, such as overshooting and quiescent mass-loss, paying major attention to the effects of the initial chemical composition of the star. We finally include modern results on explosive nucleosynthesis in SNae by Woosley & Weaver 1995. The issue of the chemical yields of Very Massive Objects (from 120 to 1000 Msol) is also addressed. Our grid of stellar yields for massive stars is complementary to the results by Marigo et al. (1996, 1997) on the evolution and nucleosynthesis of low and intermediate mass stars, also based on the Padova evolutionary tracks. Altogether, they represent a complete set of stellar yields of unprecedented homogeneity and self-consistency. Our new stellar yields are inserted in a code for the chemical evolution of the Galactic disc with infall of primordial gas, according to the formulation first suggested by Talbot & Arnett (1971, 1973, 1975) and Chiosi (1980). As a first application, the code is used to develop a model of the chemical evolution of the Solar Vicinity, with a detailed comparison to the available observational constraints.