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 ρ Ophiuchi star-forming cloud core to date. The survey covers 1 deg2, which corresponds to a projected area of ~2.2 pc × 2.2 pc at the distance of the Ophiuchus clouds (125 ± 25 pc). Mapping was carried out in the J (1.25 μm), H (1.63 μm), and K (2.22 μm) bands, to 90%, 10 σ completeness limits of J = 15.0, H = 14.5, and K = 14.0. We have cataloged 4495 sources, of which 2070 have K ≤ 14.0 and 2425 more either have 5 σ or better detections in the K band (for 14.0 ≤ K ≤ 14.5) or have 4 σ or better detections in at least two of the three survey bands (for K ≥ 14.5). We present accurate astrometry and photometry for all identified sources. We also tabulate cross-identifications 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.