Journal article
A Catalog of X-ray Point Sources from Two Megaseconds of Chandra Observations of the Galactic Center
The Astrophysical journal. Supplement series, Vol.181(1), pp.110-128
03/01/2009
DOI: 10.1088/0067-0049/181/1/110
Abstract
We present a catalog of 9017 X-ray sources identified in Chandra observations of a 2°× 0fdg8 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 × 1032 erg s−1 (0.5–8.0 keV; 90% confidence) over an area of 1 deg2, 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 <0farcs5. 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 ≈ 0fdg1.
Details
- Title: Subtitle
- A Catalog of X-ray Point Sources from Two Megaseconds of Chandra Observations of the Galactic Center
- Creators
- M. P Muno - California Institute of TechnologyF. E Bauer - Geophysical LaboratoryF. K Baganoff - Massachusetts Institute of TechnologyR. M Bandyopadhyay - University of FloridaG. C BowerW. N Brandt - Pennsylvania State UniversityP. S Broos - Pennsylvania State UniversityA Cotera - Search for Extraterrestrial IntelligenceS. S Eikenberry - University of FloridaG. P Garmire - Pennsylvania State UniversityS. D Hyman - Sweet Briar CollegeN. E Kassim - United States Naval Research LaboratoryC. C LangT. J. W Lazio - United States Naval Research LaboratoryC Law - The Netherlands Cancer InstituteJ. C Mauerhan - University of California, Los AngelesM. R Morris - University of California, Los AngelesT Nagata - Kyoto UniversityS Nishiyama - National Astronomical Observatory of JapanS Park - Pennsylvania State UniversityS. V Ramirez - California Institute of TechnologyS. R Stolovy - California Institute of TechnologyR Wijnands - University of AmsterdamQ. D Wang - University of Massachusetts AmherstZ Wang - McGill UniversityF Yusef-Zadeh - Northwestern University
- Resource Type
- Journal article
- Publication Details
- The Astrophysical journal. Supplement series, Vol.181(1), pp.110-128
- DOI
- 10.1088/0067-0049/181/1/110
- ISSN
- 0067-0049
- eISSN
- 1538-4365
- Language
- English
- Date published
- 03/01/2009
- Academic Unit
- Physics and Astronomy; Liberal Arts and Science Admin
- Record Identifier
- 9984428779102771
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