The Infrared Luminosity Function of AKARI 90$μ$m Galaxies in the Local Universe

Abstract: Local infrared (IR) luminosity functions (LFs) are necessary benchmarks for high-redshift IR galaxy evolution studies. Any accurate IR LF evolution studies require accordingly accurate local IR LFs. We present infrared galaxy LFs at redshifts redshifts of $z \leq 0.3$ from AKARI space telescope, which performed an all-sky survey in six IR bands (9, 18, 65, 90, 140 and 160 micron) with 10 times better sensitivity than its precursor IRAS. Availability of 160 micron filter is critically important in accurately measuring total IR luminosity of galaxies, covering across the peak of the dust emission. By combining data from Wide-field Infrared Survey Explorer (WISE), Sloan Digital Sky Survey (SDSS) Data Release 13 (DR13), 6-degree Field Galaxy Survey (6dFGS) and the 2MASS Redshift Survey (2MRS), we created a sample of 15,638 local IR galaxies with spectroscopic redshifts, factor of 7 larger compared to previously studied AKARI -SDSS sample. After carefully correcting for volume effects in both IR and optical, the obtained IR LFs agree well with previous studies, but comes with much smaller errors. Measured local IR luminosity density is $\Omega_{IR}=$ 1.19$\pm$0.05 $\times 10^{8}$ L$_{\odot}$ Mpc$^{-3}$. The contributions from luminous infrared galaxies and ultra luminous infrared galaxies to IR are very small, 9.3 per cent and 0.9 per cent, respectively. There exists no future all sky survey in far-infrared wavelengths in the foreseeable future. The IR LFs obtained in this work will therefore remain an important benchmark for high-redshift studies for decades.