Abstract
We present the photometric properties of a sample of infrared (IR) bright dust-obscured galaxies (DOGs). Combining wide and deep optical images obtained with the Hyper Suprime-Cam on the Subaru Telescope and all-sky mid-IR (MIR) images taken with Wide-Field Infrared Survey Explorer, we discovered 48 DOGs with i - K <sub>s</sub> > 1.2 and i - [22] > 7.0, where i, K <sub>s</sub> , and [22] represent AB magnitude in the i-band, K <sub>s</sub> -band, and 22 μm, respectively, in the GAMA 14 hr field (∼ 9 deg <sup>2</sup> ). Among these objects, 31 (∼ 65%) show power-law spectral energy distributions (SEDs) in the near-IR (NIR) and MIR regime, while the remainder show an NIR bump in their SEDs. Assuming that the redshift distribution for our DOGs sample is Gaussian, with mean and sigma z = 1.99 ± 0.45, we calculated their total IR luminosity using an empirical relation between 22 μm luminosity and total IR luminosity. The average value of the total IR luminosity is (3.5 ± 1.1) × 10 <sup>13</sup> L⊙, which classifies them as hyper-luminous infrared galaxies. We also derived the total IR luminosity function (LF) and IR luminosity density (LD) for a flux-limited subsample of 18 DOGs with 22 μm flux greater than 3.0 mJy and with i-band magnitude brighter than 24 AB magnitude. The derived space density for this subsample is log Φ = -6.59 ± 0.11 [Mpc <sup>-3</sup> ]. The IR LF for DOGs including data obtained from the literature is fitted well by a double-power law. The derived lower limit for the IR LD for our sample is ρ <sub>IR</sub> ∼3.8 × 10 <sup>7</sup> [L⊙ Mpc <sup>-3</sup> ] and its contributions to the total IR LD, IR LD of all ultra-luminous infrared galaxies, and that of all DOGs are > 3%, > 9%, and > 15%, respectively.