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Description
This table contains the results of a 96.7-ks Chandra observation of one of the youngest, most embedded, and most massive young stellar clusters studied to this date in X-rays, namely the embedded young cluster, RCW 38. 460 X-ray sources were detected in the field, of which 360 are confirmed to be associated with the RCW 38 cluster. The cluster members range in luminosity from 10<sup>30</sup> to 10<sup>33.5</sup> erg/s. Over 10% of the cluster members with over 100 counts were found to exhibit flares, while about 15% of the cluster members with over 30 counts were variable. Of the sources identified as cluster members, 160 have near-infrared (NIR) counterparts either in the Two Micron All Sky Survey (2MASS) database or which were detected via Very Large Telescope observations. Of these, about 20% appear to have optically thick disks. An additional 353 cluster members were identified through NIR observations, of which at least 50% possess optically thick disks. Over 100 X-ray sources were fit as absorbed Raymond-Smith-type plasmas and the authors found that the column to the cluster members varies from 10<sup>21.5</sup> to 10<sup>23</sup> cm<sup>-2</sup>. Comparing the gas to dust absorption signatures in these stars they found N<sub>H</sub> = A<sub>V</sub> (2 x 10<sup>21</sup>) cm<sup>-2</sup>. They also found that the cluster contains 31 candidate OB stars and is centered about 10" (0.1 pc) west of the primary source of its ionization, the O5 star IRS 2. The cluster has a peak central density of about 400 X-ray sources pc<sup>-2</sup>. The authors estimate that the total cluster membership exceeds 2000 stars. The Chandra observation of RCW 38 took place on 2001 December 10-11 and lasted 96.7 ks. It used Advanced CCD Imaging Spectrometer (ACIS) chips 0, 1, 2, 3, 6 and 7 in very faint mode. The combined field of view (FOV) of the 4 chips in the imaging array (0-3, ACIS-I) is 16.9' x 16.9'. The aimpoint of the array was 8 59 19.20, -47 30 22.0 (J2000.0), and Chandra's roll angle was 51 degrees. The source detection algorithm PWDetect was run on the cleaned events list across the entire ACIS-I array, and found 460 sources, including 31 sources with more than 200 net counts, 49 sources with 100-200 net counts, 71 sources with 50-100 net counts, and 78 sources with 20-50 net counts. NIR matches were found for 349 of the 460 X-ray sources, including 294 of the 360 cluster members and 55 of the 100 nonmembers. This table was created by the HEASARC in February 2007 based on the merger of Tables 1, 10 and 11 from the reference paper which were obtained from the AJ website. It does not include the results from either the quartile analysis of the sources which were presented in Tables 2 and 3 or of the spectral analysis of some of the sources which were presented in Tables 5 through 9 of the reference paper. This is a service provided by NASA HEASARC .
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