Wilms J (2007)
Publication Status: Published
Publication Type: Journal article
Publication year: 2007
Publisher: EDP SCIENCES S A
Book Volume: 461
Pages Range: L9-L12
Journal Issue: 1
DOI: 10.1051/0004-6361:20066527
Context. Wolf Rayet/black hole binaries are believed to exist as a later evolutionary product of high-mass X-ray binaries. Hundreds of such binaries may exist in galaxies, but only a few of them are close enough to be observed as X-ray binaries. Only a couple of candidates have been reported so far.Aims. Based on XMM-Newton observations, we report the positional coincidence of the brightest X-ray source in NGC 300 (NGC 300 X-1) with a Wolf-Rayet candidate. Temporal and spectral analysis of the X-ray source is performed.Methods. We determine an accurate X-ray position of the object, and derive light curves, spectra and flux in four XMM-Newton observations.Results. The positions of the X-ray source and the helium star candidate coincide within 0".11 +/- 0".45. The X-ray light curves show irregular variability. During one XMM-Newton observation, the flux increased by about a factor of ten in 10 h. The spectrum can be modelled by a power-law with Gamma similar to 2.45 with additional relatively weak line emission, notably around 0.95 keV. The mean observed (absorbed) luminosity in the 0.2-10 keV band is similar to 2 x 10(38) erg s(-1).Conclusions. NGC 300 X-1 is a good candidate for a Wolf-Rayet/black-hole X-ray binary: its position coincides with a Wolf-Rayet candidate and the unabsorbed X-ray luminosity reached L0.2-10 keV similar to 1 x 10(39) erg s(-1), suggesting the presence of a black hole.
APA:
Wilms, J. (2007). A Wolf-Rayet/black-hole X-ray binary candidate in NGC 300. Astronomy & Astrophysics, 461(1), L9-L12. https://dx.doi.org/10.1051/0004-6361:20066527
MLA:
Wilms, Jörn. "A Wolf-Rayet/black-hole X-ray binary candidate in NGC 300." Astronomy & Astrophysics 461.1 (2007): L9-L12.
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