AChandraACIS Study of 30 Doradus. II. X-Ray Point Sources in the Massive Star Cluster R136 and Beyond

We have studied the X-ray point source population of the 30 Doradusstar-forming complex in the Large Magellanic Cloud usinghigh-spatial-resolution X-ray images and spatially-resolved spectra obtainedwith the Advanced CCD Imaging Spectrometer (ACIS) aboard the Chandra X-rayObservatory. Here we describe the X-ray sources in a 17' x 17' field centeredon R136, the massive star cluster at the center of the main 30 Dor nebula. Wedetect 20 of the 32 Wolf-Rayet stars in the ACIS field. R136 is resolved at thesubarcsecond level into almost 100 X-ray sources, including many typical O3--O5stars as well as a few bright X-ray sources previously reported. Over twoorders of magnitude of scatter in L_X is seen among R136 O stars, suggestingthat X-ray emission in the most massive stars depends critically on the detailsof wind properties and binarity of each system, rather than reflecting thewidely-reported characteristic value L_X/L_bol ~ 10^{-7}. Such a canonicalratio may exist for single massive stars in R136, but our data are too shallowto confirm this relationship. Through this and future X-ray studies of 30Doradus, the complete life cycle of a massive stellar cluster can be revealed.Comment: 31 pages, 6 bitmapped figures, 5 tables; accepted to A