CHANDRA DETECTS THE RARE OXYGEN-TYPE WOLF-RAYET STAR WR 142 AND OB STARS IN BERKELEY 87

Journal Article · Tue Jun 01 00:00:00 EDT 2010 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/715/2/1327· OSTI ID:21450900

Sokal, Kimberly R; Skinner, Stephen L ^[1]; Zhekov, Svetozar A ^[2]; Guedel, Manuel ^[3]; Schmutz, Werner ^[4]

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1. CASA, University of Colorado, Boulder, CO 80309-0389 (United States)
2. JILA, University of Colorado, Boulder, CO 80309-0440 (United States)
3. Department of Astronomy, University of Vienna, Tuerkenschanzstr. 17, A-1180 Vienna (Austria)
4. Physikalisch-Meteorologisches Observatorium Davos and World Radiation Center (PMOD/WRC), Dorfstrasse 33, CH-7260 Davos Dorf (Switzerland)

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.

• OSTI ID: 21450900
• Journal Information: Astrophysical Journal, Vol. 715, Issue 2; Other Information: DOI: 10.1088/0004-637X/715/2/1327; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
COSMIC GAMMA BURSTS
EMISSION
HARD X RADIATION
OXYGEN
SOFT X RADIATION
SUPERNOVAE
WOLF-RAYET STARS
BINARY STARS
COSMIC RADIATION
ELECTROMAGNETIC RADIATION
ELEMENTS
ERUPTIVE VARIABLE STARS
IONIZING RADIATIONS
MAIN SEQUENCE STARS
NONMETALS
PRIMARY COSMIC RADIATION
RADIATIONS
STARS
VARIABLE STARS
X RADIATION