Near‐infrared study of the Carina Nebula

Abstract

We have carried out near-infrared (NIR) imaging observations of the Carina Nebula for an area of ~400 arcmin² including the clusters Trumpler 14 and Trumpler 16, with 10 σ limits of J ~ 18.5, H ~ 17.5, and K_s ~ 16.5 mag. A total of 544 Class II candidates, 11 Class I candidates, and 40 red (H - K_s > 2) sources have been found. The majority of the Class II candidates are found to be distributed toward the clusters, whereas most of the red NIR sources are concentrated to the southeast of Trumpler 16, along the V-shaped dust lane. We found indications of ongoing star formation near the three MSX sources, G287.51-0.49, G287.47-0.54, and G287.63-0.72, where red NIR sources and X-ray sources are seen. In particular, two hard X-ray sources are identified near G287.47-0.54, one of which does not have an NIR counterpart and may be associated with a Class I/Class 0 object. The color-magnitude diagrams of the clusters suggest very young stellar population (<3 Myr). The K_s-band luminosity function (KLF) of Trumpler 14 shows a sharp peak at the faint end, likely due to the onset of deuterium burning. The KLF of Trumpler 16, in contrast, rises smoothly until it turns over. The slopes of the mass functions derived for the clusters are in agreement with the canonical Salpeter value for the field stars.