Deep Near-Infrared Observations and Identifications of Chandra Sources in Orion Molecular Clouds 2 and 3

We conducted deep near-infrared (NIR) imaging observations of Orion molecular clouds 2 and 3 using the Quick Infrared Camera on the 88 inch (2.2 m) telescope of the University of Hawaii. Our purposes were (1) to generate a comprehensive NIR source catalog of these star-forming clouds and (2) to identify the NIR counterpart of the Chandra X-ray sources that have no counterpart in the Two Micron All Sky Survey (2MASS) catalog. Our J-, H-, and K-band observations are ~2 mag deeper than those of 2MASS and match the current Chandra observation well. We detected 1448 NIR sources, for which we derived the position, the J-, H-, and K-band magnitude, and the 2MASS counterpart. Using this catalog, we identified the NIR counterpart for ~42% of the 2MASS unidentified Chandra sources. The nature of these Chandra sources are discussed using their NIR colors and spatial distributions, and a dozen protostar and brown dwarf candidates are identified.