Galactic Chemical Evolution: The Solar Neighborhood

Abstract

Galactic chemical evolution models are presented, based on our software package "Galaxy Evolution tool." One of the strongest constraints on models of the Milky Way is the metallicity distribution of dwarf stars in the solar neighborhood, since it is sensitive to both star formation history and metallicity evolution. We present a dual-phase metal-enriched infall model that reproduces observed properties in the solar vicinity including the latest metallicity distribution of local K-dwarfs. We find that a model of Galactic formation in which primordial gas fuels the earliest epoch of star formation, followed by ongoing star formation from newly accreted gas, is able to match empirical constraints. The issue of the nature of infalling gas is addressed through the construction of models which allow the Galactic thin disk to form from slightly metal-enriched gas with alpha-element enhancement. Implications of these results are discussed in light of recent measurements of Galactic High-Velocity Clouds.