THE MASS-DEPENDENT CLUSTERING HISTORY OF K-SELECTED GALAXIES AT z < 4 IN THE SXDS/UDS FIELD

We investigate mass-dependent galaxyevolution based on a large sample of (more than 50,000) K-bandselected galaxiesin a multi-wavelength catalog of the Subaru/XMM-Newton Deep Survey and the UKIRT Infrared Deep Sky Survey/Ultra Deep Survey. We employ optical to near-infrared photometry to determine photometric redshiftsof these galaxies. Then, we estimate the stellar massof our sample galaxiesusing a standard fitting procedure as we used for estimation of the photometric redshift. From the sample galaxies, we obtain the stellar massfunction of galaxiesand the cosmic stellar massdensity up to z ~ 4. Our results are consistent with previous studies and we find a considerable number of low-mass galaxies(M * ~ 1010.5) at the redshiftrange 3 < z < 4. By combining stellar massesand spatial distributions of galaxiesderived from a large number of galaxiesin the contiguous wide and deep field, we examine properties of the mass-dependent clustering of galaxies. The correlation functions of our sample galaxiesshow clear evolution and they connect to that in the local universe consistently. Also, we find that the massive galaxiesshow strong clustering throughout our studied redshiftrange. The correlation length of massive galaxiesrapidly decreases from z = 4 to 2. The mass of dark halos hosting the intermediate-mass value galaxieschanges from high (1014 M ☉) to low (1013 M ☉) with decreasing redshiftat around z ~ 2. We also find some high-mass density regions of massive galaxiesat 1.4 ≤ z < 2.5 in our sample. These concentrations of massive galaxiesmay be candidate progenitors of the present-day clusters of galaxies. At this redshiftrange, massive star-forming galaxiesare the dominant population making up the structures and the passively evolving galaxiesshow stronger clustering and they may have formed earlier than those star-forming galaxies.