Deep Near Infrared Observations of the X-ray Emitting Class 0 Protostar   Candidates in the Orion Molecular Cloud-3
  We obtained near infrared (NIR) imaging with the Subaru Telescope of the class 0 protostar candidates in the Orion Molecular Cloud-3, two of which were discovered to have X-ray emission by the Chandra X-ray Observatory. We found strong evidence for the class~0 nature of the X-ray sources. First, our deep K-band image shows no emission brighter than 19.6 mag from both of these X-ray sources. Since class I protostars or class II T Tauri stars should be easily detected in the NIR with this sensitivity, the lack of K-band detection suggests that they are likely much more obscured than class I protostars. Second, our H2 v=1-0 S(1) image shows a bubble-like feature from one of the X-ray class 0 protostar candidates, which reinforces the idea that this is a class 0 protostar. We also discuss the nature of nine NIR sources found in our deep image based on their colors, spatial coincidence with millimeter cores, and the properties of their X-ray counterparts. 
M. Tsujimoto (1), K. Koyama (1), Y. Tsuboi (2), G. Chartas (2), M.   Goto (3), N. Kobayashi (3), H. Terada (3), A. T. Tokuna...