Clustering of infrared-bright dust-obscured galaxies revealed by the Hyper Suprime-Cam and WISE


Abstract in English

We present measurements of the clustering properties of a sample of infrared (IR) bright dust-obscured galaxies (DOGs). Combining 125 deg$^2$ of 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 have discovered 4,367 IR-bright DOGs with $(i - [22])_{rm AB}$ $>$ 7.0 and flux density at 22 $mu$m $>$ 1.0 mJy. We calculate the angular autocorrelation function (ACF) for a uniform subsample of 1411 DOGs with 3.0 mJy $<$ flux (22 $mu$m) $<$ 5.0 mJy and $i_{rm AB}$ $<$ 24.0. The ACF of our DOG subsample is well-fit with a single power-law, $omega (theta)$ = (0.010 $pm$ 0.003) $theta^{-0.9}$, where $theta$ 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. (2008). We assume that the redshift distribution for our DOG sample is Gaussian, and consider 2 cases: (1) the redshift distribution is the same as IR-faint DOGs with flux at 22 $mu$m $<$ 1.0 mJy, mean and sigma $z$ = 1.99 $pm$ 0.45, and (2) $z$ = 1.19 $pm$ 0.30, as inferred from their photometric redshifts. The inferred correlation length of IR-bright DOGs is $r_0$ = 12.0 $pm$ 2.0 and 10.3 $pm$ 1.7 $h^{-1}$ Mpc, respectively. IR-bright DOGs reside in massive dark matter halos with a mass of $log [langle M_{mathrm{h}} rangle / (h^{-1} M_{odot})]$ = 13.57$_{-0.55}^{+0.50}$ and 13.65$_{-0.52}^{+0.45}$ in the two cases, respectively.

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