Strong Spatial Clustering of UV-selected Galaxies with Magnitude Ks<20.5 and Redshift Z~2

Abstract

We obtained deep 8.5'x8.5' near-infrared images within four high-redshift survey fields, measured the Ks magnitudes of 300 optically selected galaxies with spectroscopic redshift 1.8<z<2.6, and compared the spatial clustering strength of galaxies with Ks<20.5 and Ks>20.5. We found at greater than 95% confidence that the brighter galaxies cluster more strongly. The best-fit correlation lengths for the bright and faint samples are 10+-3 and 4+-0.8 comoving Mpc/h, respectively (1sigma), although the unusual density of bright QSOs in one of our survey fields may imply that the result is not representative of the universe as a whole. Neglecting this possibility, the correlation length for the optically selected sample with Ks<20.5 agrees well with that reported for comparably bright near-IR-selected samples. The differences in correlation length between optically selected and near-IR-selected samples have been presented as evidence that the two techniques find orthogonal populations of high-redshift galaxies. Our results favor a more nuanced view.

Accepted for publication in ApJL