Simulations of Galactic Chemical Evolution: B[CLC]a[/CLC] Enrichment

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