Deep Near Infrared Imaging toward Vela Molecular Ridge C - 1: A   Remarkable Embedded Cluster in RCW 36 -
  We present deep near-infrared (J, H, Ks) images toward an embedded cluster which lies in a C18O clump in the cloud C of the Vela Molecular Ridge. This cluster has at least ~ 350 members and a radius of ~ 0.5 pc. The stellar surface number density is approximately 3000 stars pc^-2 in the central 0.1 pc x 0.1 pc region of the cluster. This is much higher than most of the young clusters within 1 kpc of the Sun. From the comparison of the luminosity function and near-infrared excess fraction with those of other embedded clusters, we estimate that the age of this cluster is approximately 2-3 Myr. This cluster exhibits an excess of brighter stars in its central region, from which we conclude that the more massive stars are located near the cluster center. 
D. Baba, T. Nagata, T. Nagayama, C. Nagashima, D. Kato, M. Kurita, S.   Sato, Y. Nakajima, M. Tamura, H. Nakaya, and K. Sugitani