Hyper-luminous dust-obscured galaxies discovered by the Hyper Suprime-Cam on Subaru and WISE.

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-skymid-IR (MIR) images taken withWide- Field Infrared Survey Explorer, we discovered 48 DOGs with i--K_s >1.2 and i--[22]>7.0, where i, K_s, and [22] represent AB magnitude in the i-band, K_s-band, and 22μm, respectively, in the GAMA 14 hr field (~9deg2). Among these objects, 31 (~65%) show powerlaw 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 22μm luminosity and total IR luminosity. The average value of the total IR luminosity is (3.5±1.1)×10¹³ 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 22μm flux greater than 3.0mJy 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--3]. 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 ρIR ~3.8×10⁷ [LMpc^-3] and its contributions to the total IR LD, IR LD of all ultraluminous infrared galaxies, and that of all DOGs are >3%, >9%, and >15%, respectively. [ABSTRACT FROM AUTHOR]