1) Speaker: H. Hirashita (ASIAA, Taiwan)
Title: “Theoretical modeling of dust evolution in galaxies”
Dust plays an important role in various processes in the interstellar medium of galaxies. Thus, clarifying the evolution of dust is essentially important in studying galaxy evolution. For the evolution of dust, it is important to understand the dust amount and the dust properties (especially the grain size distribution). We modeled the evolution of these two aspects in a consistent framework and proposed the following dust evolution scenario: Dust formation in stellar ejecta is important for the dust enrichment in the early stage of galaxy evolution or in the metal-poor phase. The subsequent evolutions of dust amount and grain size distribution are governed by interstellar processing of dust. In particular, grain disruption by shattering and dust growth by accretion enhance the abundance of small grains while coagulation pushes those created small grains to large sizes. We also show that the above processes governing dust evolution have a variety of impacts on some observable quantities such as extinction curves. I also talk about our recent efforts of implementing the above dust evolution processes into hydrodynamical galaxy evolution simulations. We have recently implemented dust evolution into a cosmological simulation, based on which we are able to predict the dust evolution over a cosmological time and volume.