Cosmic star formation history and AGN evolution near and far: from AKARI to SPICA

TL;DR

This paper utilizes AKARI satellite data to analyze infrared luminosity functions, revealing dust-obscured cosmic star formation and AGN evolution from redshift 0 to 2.2, and discusses future prospects with the SPICA telescope.

Contribution

It presents new infrared luminosity functions at various redshifts using AKARI data, improving accuracy by continuous mid-IR coverage, and discusses future observations with SPICA.

Findings

Revealed dust-hidden cosmic star formation history from z=0 to 2.2.

Constructed infrared luminosity functions at multiple redshifts.

Demonstrated improved luminosity measurements with AKARI's continuous filter coverage.

Abstract

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 these both at low and high redshifts. The AKARI performed an all sky survey in 6 IR bands (9, 18, 65, 90, 140, and 160$\mu$m) 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, AKARI can measure the total infrared luminosity ($L_{TIR}$) of individual galaxies much more precisely, and thus, the total infrared luminosity density of the local Universe. In the AKARI NEP deep field, we construct restframe 8$\mu$m, 12$\mu$m, and total infrared (TIR) luminosity functions (LFs) at 0.15$<z<$2.2 using 4128 infrared sources. A continuous filter coverage in the mid-IR wavelength (2.4, 3.2, 4.1, 7, 9, 11, 15, 18, and 24$\mu$m) by the AKARI satellite allows us to estimate restframe 8$\mu$m and 12$\mu$m 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. The next generation space infrared telescope, SPICA, will revolutionize our view of the infrared Universe with superb sensitivity of the cooled 3m space telescope. We conclude with our survey proposal and future prospects with SPICA.