Suzaku X-Ray Spectroscopy of a Peculiar Hot Star in the Galactic Center Region

Abstract

We present the results of a Suzaku study of a bright point-like source in the 6.7 keV intensity map of the Galactic center region. We detected an intense FeXXV 6.7 keV line with an equivalent width of ~1 keV as well as emission lines of highly ionized Ar and Ca from a spectrum obtained by the X-ray Imaging Spectrometer. The overall spectrum is described very well by a heavily absorbed (~2x10^{23}cm^{-2}) thin thermal plasma model with a temperature of 3.8+/-0.6 keV and a luminosity of ~3x10^{34} erg s^{-1} (2.0--8.0 keV) at 8 kpc. The absorption, temperature, luminosity, and the 6.7 keV line intensity were confirmed with the archived XMM-Newton data. The source has a very red (J-Ks=8.2 mag) infrared spectral energy distribution (SED), which was fitted by a blackbody emission of ~1000 K attenuated by a visual extinction of ~31 mag. The high plasma temperature and the large X-ray luminosity are consistent with a wind-wind colliding Wolf-Rayet binary. The similarity of the SED to those of the eponymous Quintuplet cluster members suggests that the source is a WC-type source.

Accepted for publication on PASJ Vol.60, SP-1, 2008

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Cited by in corpus (12)

• Spatial distribution of Galactic Wolf-Rayet stars and implications for the global population
• Near-infrared counterparts to Chandra X-ray sources toward the Galactic Center. II. Discovery of Wolf-Rayet stars and O supergiants
• Suzaku Spectroscopy of an X-Ray Reflection Nebula and a New Supernova Remnant Candidate in the Sgr B1 Region
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• Global Distribution of Fe K alpha Lines in the Galactic Center Region Observed with the Suzaku Satellite
• X-ray diagnostics of massive star winds
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• Three New Galactic Center X-ray Sources Identified with Near-Infrared Spectroscopy
• Study of the luminous blue variable star candidate G26.47+0.02 and its environment
• Near-infrared counterparts of Chandra X-ray sources toward the Galactic Center
• Long Term X-Ray Spectral Variation of the Wolf-Rayet Binary WR 102-1 in the Galactic bulge: evidence for wind distortion in the binary