Clustering of Dust-Obscured Galaxies at z ~ 2

Abstract

We present the angular autocorrelation function of 2603 dust-obscured galaxies (DOGs) in the Boötes field of the NOAO Deep Wide-Field Survey. DOGs are red, obscured galaxies, defined as having R − [ 24] ⩾ 14 (F24/FR≳ 1000). Spectroscopy indicates that they are located at 1.5 ≲ z ≲ 2.5. We find strong clustering, with r0 = 7.40−0.84+1.27 h−1 Mpc for the full F24 > 0.3 mJy sample. The clustering and space density of the DOGs are consistent with those of submillimeter galaxies, suggestive of a connection between these populations. We find evidence for luminosity-dependent clustering, with the correlation length increasing to r0 = 12.97−2.64+4.26 h−1 Mpc for brighter (F24 > 0.6 mJy) DOGs. Bright DOGs also reside in richer environments than fainter ones, suggesting these subsamples may not be drawn from the same parent population. The clustering amplitudes imply average halo masses of log M = 12.2−0.2+0.3 M☉ for the full DOG sample, rising to log M = 13.0−0.3+0.4 M☉ for brighter DOGs. In a biased structure formation scenario, the full DOG sample will, on average, evolve into ~3L* present-day galaxies, whereas the most luminous DOGs may evolve into brightest cluster galaxies.