Oxford University Press (OUP), Monthly Notices of the Royal Astronomical Society, 2(452), p. 1684-1693
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We present infrared (IR) galaxy luminosity functions (LFs) in the AKARI North Ecliptic Pole (NEP) deep field using recently-obtained, wider Canada-France-Hawaii Telescope (CFHT) optical/near-IR images. AKARI has obtained deep images in the mid-infrared (IR), covering 0.6 deg(2) of the NEP deep field. However, our previous work was limited to the central area of 0.25 deg(2) due to the lack of optical coverage of the full AKARI NEP survey. To rectify the situation, we recently obtained CFHT optical and near-IR images over the entire AKARI NEP deep field. These new CFHT images are used to derive accurate photometric redshifts, allowing us to fully exploit the whole AKARI NEP deep field. AKARI's deep, continuous filter coverage in the mid-IR wavelengths (2.4, 3.2, 4.1, 7, 9, 11, 15, 18, and 24 mu m) exists nowhere else, due to filter gaps of other space telescopes. It allows us to estimate rest-frame 8 and 12 mu m luminosities without using a large extrapolation based on spectral energy distribution fitting, which was the largest uncertainty in previous studies. Total infrared (TIR) luminosity is also obtained more reliably due to the superior filter coverage. The resulting rest-frame 8 and 12 mu m, and TIR LFs at 0.15 \textless z \textless 2.2 are consistent with previous works, but with reduced uncertainties, especially at the high-luminosity end, thanks to the wide-field coverage. In terms of cosmic infrared luminosity density (Omega(IR)), we found that the Omega(IR) evolves as proportional to(1 + z)(4.2+0.4).