Subproject A6: A Theoretical Chemodynamical Model of the Milky Way Disk
Andreas Just (ARI), Volker Springel (HITS/ARI)
During the first funding period, a sophisticated chemical enrichment model tracking nine chemical elements was implemented in the moving-mesh code AREPO in order to include chemical enrichment in cosmological hydrodynamic simulations of disk galaxies. The simulation results for metallicity trends including enrichment from supernovae of type II and Ia and from asymptotic giant branch stars begin to resemble the observed abundance ratios as a function of metallicity, but a number of discrepancies remain that still need to be addressed. Furthermore, recognizing the shortcomings of existing disk models, a novel iterative approach for the realization of equilibrium N-body systems for given density distributions has been developed in subproject A6, which allows one to produce disk galaxies with realistic velocity distributions. The underlying code will be made publicly available.
In the second funding period, we will explore the following key questions: What is the role of the thick disk? What are the star formation history, the dynamical heating, and the gas infall rate as a function of Galactocentric distance? How much gas infall as a function of time is required to understand the element abundance distributions in the Galactic disk? How important is radial migration in the disk to understand the abundance distribution in the solar neighborhood? Can we disentangle the impact of satellite galaxies and the features of intrinsic secular evolution on the element distribution and the kinematic structure of the Milky Way disk? We will also use high-resolution cosmological simulations to test the consistency of the disk model within the standard cosmological model.