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

Abstract

We present first results of a Chandra X-ray observation of the rare oxygen-type Wolf-Rayet 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 Wolf-Rayet 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 nonthermal 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.

To appear in the Astrophysical Journal

References in corpus (10)

• Physical Properties of Wolf-Rayet Stars
• The Galactic WN stars: Spectral analyses with line-blanketed model atmospheres versus stellar evolution models with and without rotation
• Milagro Observations of Multi-TeV Emission from Galactic Sources in the Fermi Bright Source List
• Discovery of TeV Gamma-Ray Emission from the Cygnus Region of the Galaxy
• The different progenitors of type Ib, Ic SNe, and of GRB
• X-ray Emission from Nitrogen-Type Wolf-Rayet Stars
• Discovery of X-ray Emission from the Wolf-Rayet star WR142 of oxygen subtype
• XMM-Newton X-ray Observations of the Wolf-Rayet Binary System WR 147
• Chandra Observations of WR147 Reveal a Double X-ray Source
• Discovery of a [WO] central star in the planetary nebula Th 2-A

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• Clustered star formation towards Berkeley 87 / ON2. I. Multi-wavelength census and the population overlap problem
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