"Dust grains play important role in the generation of hydrogen molecule. In addition, dust grains absorb ultra-violet (UV) photons, which indicate star formation activity, and re-emit infrared (IR) photons. Hence dust is important for accurate estimation of star formation activity and the estimation of the radiation field of IR light.
We estimate the IR luminosity function, dust temperature and IRX-beta relation by cosmological simulation with code GADGET3-Osaka. Simulation results roughly agree with observational ones at z=0 but have discrepancy at z > 2. We show them and compare them with the observational results obtained by Herschel satellite and JCMT."