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2004ApJS..150...19K
Chandra Multiwavelength Project. I. First X-Ray Source Catalog
Abstract
The Chandra Multiwavelength Project (ChaMP) is a wide-area (~14 deg2)
survey of serendipitous Chandra X-ray sources, aiming to establish fair
statistical samples covering a wide range of characteristics (such as
absorbed active galactic nuclei, high-z clusters of galaxies) at flux
levels (fX~10-15to10-14 ergs s-1 cm-2) intermediate between the Chandra
deep surveys and previous missions. We present the first ChaMP catalog,
which consists of 991 near on-axis, bright X-ray sources obtained from the
initial sample of 62 observations. The data have been uniformly reduced
and analyzed with techniques specifically developed for the ChaMP and
then validated by visual examination. To assess source reliability and
positional uncertainty, we perform a series of simulations and also
use Chandra data to complement the simulation study. The false source
detection rate is found to be as good as or better than expected for
a given limiting threshold. On the other hand, the chance of missing
a real source is rather complex, depending on the source counts,
off-axis distance (or PSF), and background rate. The positional error
(95% confidence level) is usually less than 1" for a bright source,
regardless of its off-axis distance, while it can be as large as 4" for a
weak source (~20 counts) at a large off-axis distance (Doff-axis>8'). We
have also developed new methods to find spatially extended or temporary
variable sources, and those sources are listed in the catalog.
Title: Chandra Multi-wavelength Project (ChaMP). I. First X-ray Source Catalog
Authors: Kim D.-W., Cameron R.A., Drake J.J., Evans N.R., Freeman P.,
Gaetz T.J., Ghosh H., Green P.J., Harnden F.R., Karovska M.,
Kashyap P.W., Maksym P.W., Ratzlaff P.W., Schlegel E.M.,
Silverman J.D., Tananbaum A.A., Vikhlinin A.A., Wilkes B.J.
Table: ChaMP X-ray Sources
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Byte-by-byte Description of file: datafile7.txt
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Bytes Format Units Label Explanations
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1- 22 A22 --- Name ChaMP source position name in J2000
24- 27 I4 --- ObsID ChaMP X-ray source identification number
29 I1 --- CCDID The CCD identification number (1)
31- 33 I3 --- SNum Source number assigned by wavdetect
35- 44 F10.6 deg RAdeg Right Ascension in decimal degrees (J2000)
46- 55 F10.6 deg DEdeg Declination in decimal degrees (J2000)
57- 59 F3.1 arcsec Error Positional error (see section 5)
61- 64 F4.1 arcmin Doff The off-axis distance
66- 69 F4.1 arcsec Rad The 95% EE source extraction radius
(see section 3.3)
71- 76 F6.2 ks EExp Effective exposure
78- 84 A7 --- SrcFlag Source flag (see Table 3 and section 3.5)
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CXOMP J001758.9+163119 520 2 20 4.495466 16.522075 2.2 8.2 17.1 59.01