THE MASS-DEPENDENT CLUSTERING HISTORY OFK-SELECTED GALAXIES ATz< 4 IN THE SXDS/UDS FIELD

Abstract

We investigate mass-dependent galaxy evolution based on a large sample of (more than 50,000) K-band selected galaxies in a multi-wavelength catalog of the Subaru/XMM-Newton Deep Survey (SXDS) and the UKIRT Infrared Deep Sky Survey (UKIDSS)/Ultra Deep Survey (UDS). We employ the optical to near-infrared photometry to determine photometric redshifts of these galaxies. Then, we estimate the stellar mass of our sample galaxies using a standard fitting procedure. From the sample galaxies, we obtain the stellar mass function of galaxies and the cosmic stellar mass density up to z<4. Our results are consistent with previous studies and we find a considerable number of low-mass galaxies (M<10^{10.5}) at the redshift range 3<z<4. The stellar-mass dependent correlation functions of our sample galaxies show clear evolution and they connect to that in the local universe consistently. Also, the massive galaxies show strong clustering throughout our studied redshift range. The correlation length of massive galaxies rapidly decreases from z=4 to 2. We also find some high mass density regions of massive galaxies at 1.4<z<2.5 in our sample, which may be candidate progenitors of the present-day clusters of galaxies. At this redshift range, massive star-forming galaxies are the dominant population making up the structures and the passively evolving galaxies show stronger clustering and they may have formed earlier than those star-forming galaxies.