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The Multiwavelength Survey by Yale-Chile (MUSYC): Wide K-Band Imaging, Photometric Catalogs, Clustering, and Physical Properties of Galaxies at z ~ 2

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© 2008. The American Astronomical Society. All rights reserved. Printed in U.S.A.
, , Citation Guillermo A. Blanc et al 2008 ApJ 681 1099 DOI 10.1086/588018

0004-637X/681/2/1099

Abstract

We present K-band imaging of two ~30' × 30' fields covered by the Multiwavelength Survey by Yale-Chile (MUSYC) Wide NIR Survey. The SDSS 1030+05 and Cast 1255 fields were imaged with the Infrared Side Port Imager (ISPI) on the 4 m Blanco telescope at the Cerro Tololo Inter-American Observatory (CTIO) to a 5 σ point-source limiting depth of K ∼ 20 (Vega). Combining these data with the MUSYC optical UBVRIz imaging, we created multiband K-selected source catalogs for both fields. These catalogs, together with the MUSYC K-band catalog of the Extended Chandra Deep Field South (ECDF-S) field, were used to select K < 20 BzK galaxies over an area of 0.71 deg2. This is the largest area ever surveyed for BzK galaxies. We present number counts, redshift distributions, and stellar masses for our sample of 3261 BzK galaxies (2502 star-forming [sBzK] and 759 passively evolving [pBzK]), as well as reddening and star formation rate estimates for the star-forming BzK systems. We also present two-point angular correlation functions and spatial correlation lengths for both sBzK and pBzK galaxies and show that previous estimates of the correlation function of these galaxies were affected by cosmic variance due to the small areas surveyed. We have measured correlation lengths r0 of 8.89 ± 2.03 and 10.82 ± 1.72 Mpc for sBzK and pBzK galaxies, respectively. This is the first reported measurement of the spatial correlation function of passive BzK galaxies. In the ΛCDM scenario of galaxy formation, these correlation lengths at z ∼ 2 translate into minimum masses of ~4 × 1012 and ~9 × 1012 M for the dark matter halos hosting sBzK and pBzK galaxies, respectively. The clustering properties of the galaxies in our sample are consistent with their being the descendants of bright Lyman break galaxies at z ∼ 3, and the progenitors of present-day >1L* galaxies.

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10.1086/588018