Discovery and Interpretation of an X-ray Period in the Galactic Center Source CXOGC J174536.1-285638

Valerie J. Mikles(1), Stephen S. Eikenberry(1), Reba M. Bandyopadhyay(1), Michael P. Muno(2)


(1) Department of Astronomy, University of Florida, Gainesville, FL 32611
(2) Space Radiation Laboratory, Caltech, Pasadena, CA 91125

Paper: ApJ, 2008, in press

EPrint Server: 0807.0657


Abstract:

We present X-ray and infrared observations of the X-ray source CXOGC J174536.1-285638. Previous observations suggest that this source may be an accreting binary with a high-mass donor (HMXB) or a colliding wind binary (CWB). Based on the Chandra and XMM-Newton light curve, we have found an apparent 189 +/- 6 day periodicity with better than 99.997% confidence. We discuss several possible causes of this periodicity, including both orbital and superorbital interpretations. We explore in detail the possibility that the X-ray modulation is related to an orbital period and discuss the implications for two scenarios; one in which the variability is caused by obscuration of the X-ray source by a stellar wind, and the other in which it is caused by an eclipse of the X-ray source. We find that in the first case, CXOGC J174536.1-285638 is consistent with both CWB and HMXB interpretations, but in the second, CXOGC J174536.1-285638 is more likely a HMXB.


Preprints available from the authors at reba@astro.ufl.edu , or the raw TeX (no figures) if you click here.

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