A Chandra ACIS Study of 30 Doradus. II. X-Ray Point Sources in the Massive Star Cluster R136 and Beyond
Abstract
We have studied the X-ray point-source population of the 30 Doradus (30 Dor) star-forming complex in the Large Magellanic Cloud using high spatial resolution X-ray images and spatially resolved spectra obtained with the Advanced CCD Imaging Spectrometer (ACIS) on board the Chandra X-Ray Observatory. Here we describe the X-ray sources in a 17'×17' field centered on R136, the massive star cluster at the center of the main 30 Dor nebula. We detect 20 of the 32 Wolf-Rayet stars in the ACIS field. The cluster R136 is resolved at the subarcsecond level into almost 100 X-ray sources, including many typical O3-O5 stars, as well as a few bright X-ray sources previously reported. Over 2 orders of magnitude of scatter in LX is seen among R136 O stars, suggesting that X-ray emission in the most massive stars depends critically on the details of wind properties and the binarity of each system, rather than reflecting the widely reported characteristic value LX/Lbol~=10-7. Such a canonical ratio may exist for single massive stars in R136, but our data are too shallow to confirm this relationship. Through this and future X-ray studies of 30 Dor, the complete life cycle of a massive stellar cluster can be revealed.
- Publication:
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The Astronomical Journal
- Pub Date:
- April 2006
- DOI:
- 10.1086/500535
- arXiv:
- arXiv:astro-ph/0601106
- Bibcode:
- 2006AJ....131.2164T
- Keywords:
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- ISM: H II Regions;
- Galaxies: Magellanic Clouds;
- Galaxy: Open Clusters and Associations: Individual: Alphanumeric: R136;
- Stars: Wolf-Rayet;
- X-rays: individual (30 Doradus);
- X-Rays: Stars;
- Astrophysics
- E-Print:
- 31 pages, 6 bitmapped figures, 5 tables