A Near‐Infrared Imaging Survey of the ρ Ophiuchi Cloud Core

Abstract

We present results of the largest three-color near-infrared (NIR) imaging survey of the rho Ophiuchi star-forming cloud core to date. The survey covers 1 deg(2), which corresponds to a projected area of similar to 2.2 pc x 2.2 pc at the distance of the Ophiuchus clouds (125 +/- 25 pc). Mapping was carried out in the J (1.25 mu m), H (1.63 mu m), and K (2.22 mu m) bands, to 90%, 10 sigma completeness limits of J = 15.0, H = 14.5, and K = 14.0. We have cataloged 4495 sources, of which 2070 have K less than or equal to 14.0 and 2425 more either have 5 sigma or better detections in the K band (for 14.0 less than or equal to K less than or equal to 14.5) or have 4 sigma or better detections in at least two of the three survey bands (for K greater than or equal to 14.5). We present accurate astrometry and photometry for all identified sources. We also tabulate cross-identification for 449 previously observed NIR sources. Using the cross-identifications, we derive linear transformations between the differing photometric systems and use rather strict criteria to identify NIR variables.