Oral Presentation

Expansion of the dust radiation evolutionary framework to encompass the influence of dust number density within distant galactic environments

Author(s): Ryusei R. Kano (Nagoya University)

Presenter: Ryusei Kano (Nagoya University)

In the study of galaxy evolution, the presence of dust within galaxies plays a crucial role in various physical aspects, such as the spectral energy distribution (SED) and the star formation history. To investigate the dust evolution of galaxies over time, our research incorporates a comprehensive model that considers both dust and chemical evolution. By adopting this
framework, we have successfully constructed a galaxy SED model, enabling us to precisely compute the SED of nearby galaxies. However, when we apply our SED model to galaxies at
high redshifts (z ∼ 8), some modifications is necessary to reproduce their observational SED due to difference of galaxy properties. In this work, we try to change partial theory of the current SED model and reproduce the observed SEDs of very high-redshift galaxies. The molecular cloud around a young star is called a clump, which is considered to be a sphere. Since distant galaxies are considered to be compact, the density in the clumps should be higher than that of nearby galaxies. Therefore, we made the clump radius have a different dependence from the entire galaxy, and by increasing the number density of dust in a clump, we were able to obtain high dust emission, the same as the observed value. This approach allows for more highly reproducible simulations. The results suggest that distant galaxies have a higher dust number density than nearby galaxies and therefore emit more dust radiation.