Muno, M. P. and Bauer, F. E. and Baganoff, F. K. and Bandyopadhyay, R. M. and Bower, G. C. and Brandt, W. N. and Broos, P. S. and Cotera, A. and Eikenberry, S. S. and Garmire, G. P. and Hyman, S. D. and Kassim, N. E. and Lang, C. C. and Lazio, T. J. W. and Law, C. and Mauerhan, J. C. and Morris, M. R. and Nagata, T. and Nishiyama, S. and Park, S. and Ramìrez, S. V. and Stolovy, S. R. and Wijnands, R. and Wang, Q. D. and Wang, Z. and Yusef-Zadeh, F. (2009) A Catalog of X-Ray Point Sources from Two Megaseconds of Chandra Observations of the Galactic Center. Astrophysical Journal Supplement Series, 181 (1). pp. 110-128. ISSN 0067-0049 http://resolver.caltech.edu/CaltechAUTHORS:20090915-094405505
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We present a catalog of 9017 X-ray sources identified in Chandra observations of a 2°× 0°.8 field around the Galactic center. This enlarges the number of known X-ray sources in the region by a factor of 2.5. The catalog incorporates all of the ACIS-I observations as of 2007 August, which total 2.25 Ms of exposure. At the distance to the Galactic center (8 kpc), we are sensitive to sources with luminosities of 4 × 10^(32) erg s^(–1) (0.5-8.0 keV; 90% confidence) over an area of 1 deg^2, and up to an order of magnitude more sensitive in the deepest exposure (1.0 Ms) around Sgr A*. The positions of 60% of our sources are accurate to < 1" (95% confidence), and 20% have positions accurate to < 0".5. We search for variable sources, and find that 3% exhibit flux variations within an observation, and 10% exhibit variations from observation-to-observation. We also find one source, CXOUGC J174622.7 – 285218, with a periodic 1745 s signal (1.4% chance probability), which is probably a magnetically accreting cataclysmic variable. We compare the spatial distribution of X-ray sources to a model for the stellar distribution, and find 2.8σ evidence for excesses in the numbers of X-ray sources in the region of recent star formation encompassed by the Arches, Quintuplet, and Galactic center star clusters. These excess sources are also seen in the luminosity distribution of the X-ray sources, which is flatter near the Arches and Quintuplet than elsewhere in the field. These excess point sources, along with a similar longitudinal asymmetry in the distribution of diffuse iron emission that has been reported by other authors, probably have their origin in the young stars that are prominent at l ≈ 01.
|Additional Information:||© 2009 The American Astronomical Society. Received 2008 May 6; accepted 2008 September 15; published 2009 March 4. M.P.M., R.M.B., W.N.B., G.C.B., P.S.B., A.C., S.D.H., J.C.M., Q.D.W., Z.W., and F.Y.Z. received support from NASA through Chandra Award Number G06-7135 issued by the Chandra X-ray Observatory Center, which is operated by the Smithsonian Astrophsyical Observatory for and on behalf of the National Aeronautics Space Administration under contract NAS8-03060. T.J.W.L. and N.E.K. received funding for basic research in astronomy at the Naval Research Laboratory, which is supported by 6.1 base funding.|
|Subject Keywords:||Galaxy: center; X-rays: stars|
|Official Citation:||A Catalog of X-Ray Point Sources from Two Megaseconds of Chandra Observations of the Galactic Center M. P. Muno, F. E. Bauer, F. K. Baganoff, R. M. Bandyopadhyay, G. C. Bower, W. N. Brandt, P. S. Broos, A. Cotera, S. S. Eikenberry, G. P. Garmire, S. D. Hyman, N. E. Kassim, C. C. Lang, T. J. W. Lazio, C. Law, J. C. Mauerhan, M. R. Morris, T. Nagata, S. Nishiyama, S. Park, S. V. Ramìrez, S. R. Stolovy, R. Wijnands, Q. D. Wang, Z. Wang, and F. Yusef-Zadeh 2009 ApJS 181 110-128 doi: 10.1088/0067-0049/181/1/110.|
|Usage Policy:||No commercial reproduction, distribution, display or performance rights in this work are provided.|
|Deposited By:||Tony Diaz|
|Deposited On:||16 Sep 2009 23:19|
|Last Modified:||26 Dec 2012 11:22|
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