Simulations of galactic chemical evolution: Ba enrichment

We present numerical simulations of the Galactic chemical evolution perform ed by means of an N-body/smooth particle hydrodynamics code. The Galactic e nrichment of barium is studied by taking into account nucleosynthesis contr ibutions from both low-mass Type II supernovae (SNIIs), via a primary r-pro cess, and low-mass asymptotic giant branch (AGB) stars, through a metal-dep endent s-process. Recent calculations of neutron captures in stars of 1.5-3 M. and different metallicities provide the Ba yields from the AGE stars; t he Ba yields from SNIIs are derived from considerations about the solar sys tem composition. Our simulations show that these two Ba sources can explain both the [Ba/Fe] versus [Fe/H] behavior as derived from high-resolution sp ectroscopic observations of F-K giants, including the large spread of [Ba/F e] observed at low metallicities, and the ratio between the r- and s-proces s contributions to solar barium.