Galactic Chemical Evolution, Stars, and the Creation of Elements in the Big-Data Era
Date Submitted
2017-04-18 17:31:37
Chiaki Kobayashi
University of Hertfordshire
I will briefly show the successes and shortcoming of the nucleosynthesis yields, chemodynamical simulations of the Milky Way, and cosmological simulations with AGN-driven metal-dependent winds. Latest nucleosynthesis yields and a cosmological initial condition well explain most of elemental abundances in the Milky Way Galaxy. The first stars are faint supernovae (SNe) remaining ~10Msun blackholes (BHs), or no/weak SNe remaining ~100-1000 Msun seed BHs. In cosmological simulations, the latter can give AGN feedback, in good agreement with cosmic star formation rate (SFRs), BH mass-bulge mass relation (with no evolution), size-mass relation, mass-metallicity relations (MZRs, with steeper slopes at higher-z), and helps reproducing the down-sizing phenomena; colour-magnitude relations, specific SFRs, and [$\alpha$/Fe]-mass relations of ellipticals. AGN-driven winds remove the remaining gas that contains ~2% of total produced metals, and hence AGN feedback is important for quenching and enriching CGM/IGM, but not for MZRs (with only weak environmental dependence). The radial gradients of metallicity and elemental abundances will give further constraints on the formation histories of galaxies, in particular, on the merging histories.