The Stellar Population of RCW 38

We report on results of a 96.7 ks Chandra observation of one of the youngest, most embedded and massive young stellar clusters studied to date in X-rays -- RCW 38. In addition to its mass and youth, this cluster is remarkable due to its extended X-ray emission which is surrounded by a continuum radio ring. With Chandra, we detect 485 point sources ranging down to a sensitivity limit of ˜ 1028 ergs s-1. Of these sources, about 200 appear to be cluster members and most of these have IR counterparts in our VLT data. We have modeled the coronae as Raymond-Smith plasmas. We find that the column densities vary from 1020 to 1023 NH and temperature varies from 0.2 to 8 keV. Five percent of the sources exhibit flares while about 30% are classified as variable. We acknowledge support from CXC contract (NAS8-39073) and and NASA/CXC grant GO2-3105X.