Cosmic Star Formation History Required from Infrared Galaxy Number Count : Future Prospect for Infrared Imaging Surveyor (IRIS)

摘要

We constructed a model of infrared and sub-mm (hereafter IR) galaxy numbercount and estimated history of the IR luminosity density. We treat theevolutionary change of galaxy luminosities as a stepwise nonparametric form, inorder to explore the most suitable evolutionary history which reproduces thepresent observational results. We found the evolutionary patterns which satisfyboth constraints required from Cosmic Infrared Background (CIRB) and IR galaxynumber counts. One order of magnitude increase of luminosity at redshift$z=0.75 - 1.0$ was found in IR $60 \mu$m luminosity density evolution. We alsofound that a large number of galaxies ($\sim 10^7$ in the whole sky) will bedetected in all-sky survey at far-infrared by Infrared Imaging Surveyor (IRIS);Japanese infrared satellite project Astro-F.