Chandra Detects the Rare Oxygen-type Wolf-Rayet Star WR 142 and OB Stars in Berkeley 87

Autor(en)
Kimberley R. Sokal, Stephen Lee Skinner, Svetozar A. Zhekov, Manuel Güdel, Werner Schmutz
Abstrakt

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(en)
Institut für Astrophysik
Externe Organisation(en)
University of Colorado, Boulder, Physikalisch-Meteorologische Observatorium
Journal
The Astrophysical Journal: an international review of astronomy and astronomical physics
Band
715
Seiten
1327-1337
Anzahl der Seiten
11
ISSN
0004-637X
DOI
https://doi.org/10.1088/0004-637X/715/2/1327
Publikationsdatum
2010
Peer-reviewed
Ja
ÖFOS 2012
103003 Astronomie
Link zum Portal
https://ucrisportal.univie.ac.at/de/publications/d8401d19-12e9-4157-9d0d-8967a15803f8