Cosmic star formation history revealed by AKARI and Hyper Suprime-Cam

Understanding infrared (IR) luminosity is fundamental to understanding the cosmic star formation history and AGN evolution, since their most intense stages are often obscured by dust. Japanese infrared satellite, AKARI, provided unique data sets to probe this both at low and high redshift; the AKARI all sky survey in 6 bands (9-160 micrometers), and the AKARI NEP survey in 9 bands (2-24 micrometers). The AKARI performed all sky survey in 6 IR bands (9, 18, 65, 90, 140, and 160 micrometers) with 3-10 times better sensitivity than IRAS, covering the crucial far-IR wavelengths across the peak of the dust emission. Combined with a better spatial resolution, we measure the total infrared luminosity (L(sub TIR)) of individual galaxies, and thus, the total infrared luminosity density of the local Universe much more precisely than previous work. In the AKARI NEP wide field, AKARI has obtained deep images in the mid-infrared (IR), covering 5.4 deg(exp 2). However, our previous work was limited to the central area of 0.25 deg(exp 2) due to the lack of deep optical coverage. To rectify the situation, we used the newly advent Subaru telescope's Hyper Suprime-Cam to obtain deep optical images over the entire 5.4 deg(exp 2) of the AKARI NEP wide field. With this deep and wide optical data, we, for the first time, can use the entire AKARI NEP wide data to construct restframe 8um, 12um, and total infrared (TIR) luminosity functions (LFs) at z is less than 0.15 and greater than 2.2. A continuous 9-band filter coverage in the mid-IR wavelength (2.4, 3.2, 4.1, 7, 9, 11, 15, 18, and 24 micrometers by the AKARI satellite allowed us to estimate restframe 8 micrometers and 12 micrometers luminosities without using a large extrapolation based on a SED fit, which was the largest uncertainty in previous work. By combining these two results, we reveal dust-hidden cosmic star formation history and AGN evolution from z = 0 to z = 2.2, all probed by the AKARI satellite.
Meeting Information: The 4th AKARI International Conference: The Cosmic Wheel and the Legacy of the AKARI archive: from galaxies and stars to planets and life (October 17-20, 2017. The University of Tokyo), Bunkyo-ku, Tokyo, Japan
Physical characteristics: Original contains color illustrations
会議情報: 第4回「あかり」国際会議 (2017年10月17-20日. 東京大学), 文京区, 東京
形態: カラー図版あり