Chandra Multiwavelength Project X‐Ray Point Source Catalog

We present the Chandra Multiwavelength Project (ChaMP) X-ray point sourcecatalog with ~6,800 X-ray sources detected in 149 Chandra observations covering\~10 deg^2. The full ChaMP catalog sample is seven times larger than theinitial published ChaMP catalog. The exposure time of the fields in our sampleranges from 0.9 to 124 ksec, corresponding to a deepest X-ray flux limit off_{0.5-8.0} = 9 x 10^{-16} erg/cm2/sec. The ChaMP X-ray data have beenuniformly reduced and analyzed with ChaMP-specific pipelines, and thencarefully validated by visual inspection. The ChaMP catalog includes X-rayphotometric data in 8 different energy bands as well as X-ray spectral hardnessratios and colors. To best utilize the ChaMP catalog, we also present thesource reliability, detection probability and positional uncertainty. Toquantitatively assess those parameters, we performed extensive simulations. Inparticular, we present a set of empirical equations: the flux limit as afunction of effective exposure time, and the positional uncertainty as afunction of source counts and off axis angle. The false source detection rateis ~1% of all detected ChaMP sources, while the detection probability is betterthan ~95% for sources with counts >30 and off axis angle <5 arcmin. The typicalpositional offset between ChaMP X-ray source and their SDSS opticalcounterparts is 0.7+-0.4 arcsec, derived from ~900 matched sources.