Near-infrared counterparts to the Galactic Bulge Survey X-ray source population

Abstract

We report on the near-infrared matches, drawn from three surveys, to the 1640 unique X-ray sources detected by Chandra in the Galactic Bulge Survey (GBS). This survey targets faint X-ray sources in the Bulge, with a particular focus on accreting compact objects. We present all viable counterpart candidates and associate a false alarm probability (FAP) to each near-infrared match in order to identify the most likely counterparts. The false alarm probability takes into account a statistical study involving a chance alignment test, as well as considering the positional accuracy of the individual X-ray sources. We find that although the star density in the Bulge is very high, ~90% of our sources have a false alarm probability < 10%, indicating that for most X-ray sources, viable near-infrared counterparts candidates can be identified. In addition to the FAP, we provide positional and photometric information for candidate counterparts to ~95% of the GBS X-ray sources. This information in combination with optical photometry, spectroscopy and variability constraints will be crucial to characterize and classify secure counterparts.

16 pages, 14 figures, accepted for publication in MNRAS, full version of final Table (4) will be available online through MNRAS and CDS

References in corpus (8)

• The UKIRT Infrared Deep Sky Survey (UKIDSS)
• The UKIDSS Galactic Plane Survey
• The XMM-Newton Serendipitous Survey. V. The Second XMM-Newton Serendipitous Source Catalogue
• A Catalog of X-ray Point Sources from Two Megaseconds of Chandra Observations of the Galactic Center
• A Large, Uniform Sample of X-ray Emitting AGN from the ROSAT All-Sky and Sloan Digital Sky Surveys: the Data Release 5 Sample
• Near-Infrared Counterparts to Chandra X-ray Sources toward the Galactic Center. I. Statistics and a Catalog of Candidates
• Identification of twenty-three accreting binaries in the Galactic Bulge Survey
• X-ray Spectral and timing properties of the black hole x-ray transient Swift J1753.5-0127

Cited by in corpus (10)

• The Swift Bulge Survey: Motivation, Strategy, and First X-ray Results
• The Relationship Between X-ray Luminosity and Duty Cycle for Dwarf Novae and their Specific Frequency in the Inner Galaxy
• Variability of Optical Counterparts in the Chandra Galactic Bulge Survey
• The Chandra Galactic Bulge Survey: optical catalogue and point-source counterparts to X-ray sources
• Dynamical Modeling of CXOGBS J175553.2-281633: A 10 Hour Long Orbital Period Cataclysmic Variable
• Gemini Spectroscopy of Galactic Bulge Sources: A Population of Hidden Accreting Binaries Revealed?
• Spectroscopic classification of X-ray sources in the Galactic Bulge Survey
• Discovery of a Long-Lived, High Amplitude Dusty Infrared Transient
• Constraining the nature of the accreting binary in CXOGBS J174623.5-310550
• Sharp Chandra View of ROSAT All-Sky Survey Bright Sources: I. Improvement of Positional Accuracy