Chemodynamical simulations of the Milky Way Galaxy

Abstract

We simulate the chemodynamical evolution of the Milky Way Galaxy, including the nucleosynthesis yields of hypernovae and a new progenitor model for Type Ia Supernovae (SNe Ia). In our nucleosynthesis yields of core-collapse supernovae, we use light curve and spectral fitting to individual supernovae to estimate the mass of the progenitor, the explosion energy, and the iron mass produced. A large contribution of hypernovae is required from the observed abundance of Zn ([Zn/Fe] ~0). In our progenitor model of SNe Ia, based on the single degenerate scenario, the SN Ia lifetime distribution spans a range of 0.1–20 Gyr with peaks at both ~ 0.1 and 1 Gyr. A metallicity effect from white dwarf winds is required from the observed trends of elemental abundance ratios (i.e., [(α,Mn,Zn)/Fe]-[Fe/H] relations). In our simulated Milky Way-type galaxy, the kinematical and chemical properties of the bulge, disk, and halo are broadly consistent with observations. 80% of the thick disk stars are older than ~8 Gyr and tend to have larger [α/Fe] than in the thin disk.