The very wide-field gzK galaxy survey - I. Details of the clustering properties of star-forming galaxies at z ~ 2

Abstract

We present the results of clustering analysis on z ~ 2 star-forming galaxies. By combining our data with data from publicly available archives, we collect g-, zB/z- and K-band imaging data over 5.2 deg2, which represents the largest area BzK/gzK survey. We apply colour corrections to translate our filter set to those used in the original BzK selection for the gzK selection. Because of the wide survey area, we obtain a sample of 41 112 star-forming gzK galaxies at z ~ 2 (sgzK galaxies) down to KAB < 23.0, and we determine high-quality two-point angular correlation functions (ACFs). Our ACFs show an apparent excess from power-law behaviour at small angular scale (θ ≲ 0.°01), which corresponds to the virial radius of a dark halo at z ~ 2 with a mass of ~1013 M⊙. We find that the correlation lengths are consistent with the previous estimates over the whole magnitude range; however, our results are evaluated with a smaller margin of error than that in previous studies. The large amount of data enables us to determine ACFs differentially depending on the luminosity of the subset of the data. The mean halo mass of faint sgzK galaxies (22.0 < K ≤ 23.0) was found to be 〈Mh〉 = (1.32-0.12+0.09) × 1012 h-1 M⊙, whereas bright sgzK galaxies (18.0 ≤ K ≤ 21.0) were found to reside in dark haloes with a mass of 〈Mh〉 = (3.26-1.02+1.23) × 1013 h-1 M⊙.