A Public, K-Selected, Optical-to-Near-Infrared Catalog of the Extended Chandra Deep Field South (ECDFS) from the MUltiwavelength Survey by Yale-Chile (MUSYC)

We present a new K-selected, optical-to-near-infrared photometric catalog of the Extended Chandra Deep Field South (ECDFS), making it publicly available to the astronomical community. The dataset is founded on publicly available imaging, supplemented by original zJK imaging data obtained as part of the MUltiwavelength Survey by Yale-Chile (MUSYC). The final photometric catalog consists of photometry derived from nine band U-K imaging covering the full 0.5x0.5 sq. deg. of the ECDFS, plus H band data for approximately 80% of the field. The 5sigma flux limit for point-sources is K = 22.0 (AB). This is also the nominal completeness and reliability limit of the catalog: the empirical completeness for 21.75 < K < 22.00 is 85+%. We have verified the quality of the catalog through both internal consistency checks, and comparisons to other existing and publicly available catalogs. As well as the photometric catalog, we also present catalogs of photometric redshifts and restframe photometry derived from the ten band photometry. We have collected robust spectroscopic redshift determinations from published sources for 1966 galaxies in the catalog. Based on these sources, we have achieved a (1sigma) photometric redshift accuracy of Dz/(1+z) = 0.036, with an outlier fraction of 7.8%. Most of these outliers are X-ray sources. Finally, we describe and release a utility for interpolating restframe photometry from observed SEDs, dubbed InterRest. Particularly in concert with the wealth of already publicly available data in the ECDFS, this new MUSYC catalog provides an excellent resource for studying the changing properties of the massive galaxy population at z < 2. (Abridged)