Abstract

Contributed Talk - Splinter DustEvol

Friday, 13 September 2024, 15:15   (S12)

The Need for Dust Diffusion in SPH Simulations of Dust Evolution in the ISM

Leonard Romano, Kentaro Nagamine, Hiroyuki Hirashita
Universitäts-Sternwarte, Fakultät für Physik, Ludwig-Maximilians-Universität München; Max-Planck-Institut für extraterrestrische Physik; Excellence Cluster ORIGINS

The evolution of dust in galaxies is a highly multi-phase and multi-scale process. While many processes that affect the evolution of the dust grain size distribution (GSD) have been identified, the large dynamical range spanned by these processes can not be achieved with modern state-of-the-art numerical models of galaxy evolution and thus requires the use of so-called subgrid models. In this contribution, I show how the evolution of the GSD can be biased by the use of the smoothed-particle-hydrodynamics (SPH) method and propose the use of a subgrid model for dust diffusion as means of alleviating this bias. We compute the evolution of the GSD in a suite of numerical simulations of an isolated Milky-Way-like galaxy using the N-body/SPH code Gadget4-Osaka. The full GSD is sampled on a logarithmically spaced grid with 30 bins, and its evolution is calculated self-consistently with the hydrodynamical and chemical evolution of the galaxy using a state-of-the-art star-formation and feedback model as a subgrid model for the diffusion of dust and metals due to turbulent mixing on unresolved scales. We show that diffusion can significantly enhance the production of small grains and improve the agreement with the observed dust extinction curve in the Milky Way.