Yen-Hsing Lin (NTHU/ASIAA); Hiroyuki Hirashita (ASIAA)
Dust has been detected in high redshift (z>5) galaxies but the origin of dust is still being debated. Previous studies have shown possible dust sources and they would predict different grain size distributions, corresponding to vastly different extinction curves. In this paper, we investigate how the dust attenuation curves predicted by the above extinction curves could be modulated by various radiation transfer effects using two representative dust-star distribution geometries. We confirmed that the steepening and flattening effects drastically modify the attenuation curves. We could reproduce similar attenuation curves even with very different extinction curves. Thus, we conclude that it is difficult to distinguish the dust sources only with the attenuation curves. However, if we include information on dust emission and construct the IRX-beta diagram, a wider area, especially high-beta and low-IRX region covered by the observational data is more easily explained if dust sources are dominated by dust growth.