Clustering of Infrared-bright Dust-obscured Galaxies Revealed by the Hyper Suprime-Cam and WISE

Abstract

We present measurements of the clustering properties of a sample of infrared (IR)bright dust-obscured galaxies (DOGs). Combining 125 deg2 of wide and deep optical images obtained with the Hyper Suprime-Cam on the Subaru Telescope and all-sky mid-IR images taken with Wide-Field Infrared Survey Explorer, we have discovered 4367 IR-bright DOGs with ( [ ] ) - > i 22 7.0AB and flux density at 22 m >m 1.0 mJy. We calculate the angular autocorrelation function (ACF)for a uniform subsample of 1411 DOGs with 3.0 mJy <flux (22 mm)<5.0 mJy and iAB <24.0. The ACF of our DOG subsample is well-fit with a single power law, ( ) w q =(0.010 ±0.003)q-0.9, where θis in degrees. The correlation amplitude of IR-bright DOGs is larger than that of IR-faint DOGs, which reflects a flux dependence of the DOG clustering, as suggested by Brodwin et al. We assume that the redshift distribution for our DOG sample is Gaussian, and consider two cases: (1)the redshift distribution is the same as IR- faint DOGs with flux at 22 mm <1.0 mJy, mean and sigma z=1.99±0.45, and (2)z=1.19±0.30, as inferred from their photometric redshifts. The inferred correlation length of IR-bright DOGs is r0=12.0±2.0 and 10.3±1.7 -h 1 Mpc, respectively. IR-bright DOGs reside in massive dark matter halos with a mass of [ ( ) ] á ñ = - -+M h M log 13.57h 1 0.550.50 and -+13.65 0.520.45 in the two cases, respectively.