Source Catalogs Columns

Name ChaMP internal optical source ID
R.A. averaged J2000.0 RA from detections in all filters
Dec. averaged J2000.0 DEC from detections in all filters
Then for each detected filter (g,r,i) we list the SExtractor outputs (see Bertin, E., & Arnouts, S. 1996 A&AS 117, 393). Systematic error estimates (e.g., derived from scatter in the photometric solution) are not included. 999 listings indicate that no object was detected. Details are described in Green et al. (2004)
MAG_AUTO photometrically calibrated Kron magnitude
MAGERR_AUTO random error in Kron magnitude
BACKGROUND background level in ADU
FWHM_WORLD FWHM of detected source in degrees.
FLAGS These are additive integer flags; see below
CLASS_STAR Output of SExtractor star-galaxy classifier.
1= Stellar profile. 0= extended profile.
For either saturated or very faint objects, is unreliable.
SExtractor flags:
1 The object has neighbors, bright and close enough to significantly bias the photometry, or bad pixels (more than 10% of the integrated area affected).
2 The object was originally blended with another one.
4 At least one pixel of the object is saturated (or very close to).
8 The object is truncates (to close to an image boundary).
16 Object's aperture data are incomplete or corrupted.
32 Object's isophotal data are incomplete or corrupted.
64 A memory overflow occurred during deblending.
128 A memory overflow occurred during extraction.
For each source, the catalogs list:
the detection band, image frame coordinates, celestial coordinates, source shape parameters (fwhm, elongation, kron radius, semi-major and semi-minor axes), a star/galaxy separation parameter (described above ),detection flags for each filter, SExtractor MAG_AUTO and CLASS_STAR values.
For ALL catalogs, ALL MAGNITUDES ARE IN THE VEGA SYSTEM. To bring the z magnitudes back to its original AB calibration add 0.54mags (z_AB = z_VEGA + 0.54).

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Last Updated: 29 December 2003
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