Poster Presentation

Dust SEDs of Milky Way analogs in the IllustrisTNG simulations

Author(s): Chiung-Yin Chang (ASIAA/NTHU) Yu-Hsiu Huang (ASIAA/NTU) Hiroyuki Hirashita (ASIAA)

Presenter: Chiung-Yin Chang (ASIAA/NTHU)

Dust emission is important in tracing the star formation activities and the chemical enrichment in galaxies. We present our theoretical modeling of the spectral energy distributions (SEDs) in galaxies using the cosmological hydrodynamics simulation IllustrisTNG. In this work, we focus on Milky Way-like galaxies since the dust properties are well constrained observationally for the Milky Way. We first post-process the simulation output with our dust evolution model along with the so-called merger trees of individual Milky Way analogs, to calculate the evolution of dust grain size distribution. The calculation of grain size distribution is based on five important mechanisms: stellar dust production, sputtering in the hot gas, accretion of gas-phase metal, shattering in the diffuse interstellar medium (ISM), and coagulation in dense ISM. We further decompose the dust into silicate, aromatic carbon, and non-aromatic carbon in a consistent manner with the elemental abundances and the dense ISM fraction given by the simulation. Finally, we calculate the SEDs of the MW analogs by considering the dust composition and grain size distribution. The calculated SEDs successfully reproduce the observed Milky Way SED within the dispersion in the simulation sample. We also find that metallicity and dense gas fraction are the most critical factors that affect the shape of dust SED through coagulation and shattering. We also discuss the relations with other galaxy properties such as morphology.