Speaker
Description
Dust, a material that makes up only 1\% of the interstellar medium, yet it plays a key role in the evolution of galaxies by absorbing interstellar emission to allow molecular gas to cool and reach density thresholds to form stars. This absorption and eventually re-emission causes dust to be responsible for up to 50\% of the emission we gather from galaxies, making it one of the largest drivers for uncertainties in determining stellar properties, especially with the rise of highly obscured sources at high-redshift. The uncertainties get even harder to solve as the origin of dust remains one of the most difficult questions to answer as we cannot directly observe dust grains and the potential timescales at which dust growths remain long enough to not be captured by a human life time. That is why galaxy simulations that include the potential origin and evolution of dust have become a key player in understanding the efficiency of many dust evolution processes. For this talk, we will highlight one of the most detailed galaxy simulations when it comes to the evolution of dust: the GADGET4 - OSAKA simulations. This simulation suite can be calibrated to align with the stellar and gas properties from a chosen galaxy to calculate the evolution of the dust grains with 30 different grain sizes possible within the estimated grain size distribution. The talk itself focuses on the comparison in dust properties and small-to-large grain ratios between a simulated galaxy calibrated to nearby galaxy NGC628 and the observations of four nearby galaxies: NGC628, M101, M33, and NGC300. The simulations can match the observed dust mass surface densities in NGC628, yet the small-to-large grain ratio is overestimated. When the simulation varies the accretion timescale or the subgrid model describing the molecular cloud density structure, we recover that the dust mass surface density and small-to-large grain ratio remain unchanged, whereas the molecular cloud structure changes the average small-to-large grain ratio significantly depending on the location in the disk.
