Chandra Detects the Rare Oxygen-type Wolf-Rayet Star WR 142 and OB Stars in Berkeley 87
- Author(s)
- Kimberley R. Sokal, Stephen Lee Skinner, Svetozar A. Zhekov, Manuel Güdel, Werner Schmutz
- Abstract
We present first results of a Chandra X-ray observation of the rare oxygen-type Wolf-Rayet (WR) star WR 142 (= Sand 5 = St 3) harbored in the young, heavily obscured cluster Berkeley 87. Oxygen-type WO stars are thought to be the most evolved of the WRs and progenitors of supernovae or gamma-ray bursts. As part of an X-ray survey of supposedly single WR stars, we observed WR 142 and the surrounding Berkeley 87 region with Chandra ACIS-I. We detect WR 142 as a faint yet extremely hard X-ray source. Due to weak emission, its nature as a thermal or non-thermal emitter is unclear and thus we discuss several emission mechanisms. Additionally, we report seven detections and eight non-detections by Chandra of massive OB stars in Berkeley 87, two of which are bright yet soft X-ray sources whose spectra provide a dramatic contrast to the hard emission from WR 142.
- Organisation(s)
- Department of Astrophysics
- External organisation(s)
- University of Colorado, Boulder, Physikalisch-Meteorologisches Observatorium Davos World Radiation Center
- Journal
- The Astrophysical Journal: an international review of astronomy and astronomical physics
- Volume
- 715
- Pages
- 1327-1337
- No. of pages
- 11
- ISSN
- 0004-637X
- DOI
- https://doi.org/10.1088/0004-637X/715/2/1327
- Publication date
- 2010
- Peer reviewed
- Yes
- Austrian Fields of Science 2012
- 103003 Astronomy
- Portal url
- https://ucrisportal.univie.ac.at/en/publications/d8401d19-12e9-4157-9d0d-8967a15803f8