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