  The Chandra COSMOS Survey (C-COSMOS) is a large, 1.8 Ms, Chandra} program
that has imaged the central 0.5 sq.deg of the COSMOS field (centered at 10h,
+02deg) with an effective exposure of ~160ksec, and an outer 0.4sq.deg. area
with an effective exposure of ~80ksec. The limiting source detection depths are
1.9e-16 erg cm(-2) s(-1) in the Soft (0.5-2 keV) band, 7.3e(-16) erg cm^-2 s^-1
in the Hard (2-10 keV) band, and 5.7e(-16) erg cm(-2) s(-1) in the Full (0.5-10
keV) band. Here we describe the strategy, design and execution of the C-COSMOS
survey, and present the catalog of 1761 point sources detected at a probability
of being spurious of <2e(-5) (1655 in the Full, 1340 in the Soft, and 1017 in
the Hard bands). By using a grid of 36 heavily (~50%) overlapping pointing
positions with the ACIS-I imager, a remarkably uniform (to 12%) exposure across
the inner 0.5 sq.deg field was obtained, leading to a sharply defined lower
flux limit. The widely different PSFs obtained in each exposure at each point
in the field required a novel source detection method, because of the
overlapping tiling strategy, which is described in a companion paper. (Puccetti
et al. Paper II). This method produced reliable sources down to a 7-12 counts,
as verified by the resulting logN-logS curve, with sub-arcsecond positions,
enabling optical and infrared identifications of virtually all sources, as
reported in a second companion paper (Civano et al. Paper III). The full
catalog is described here in detail, and is available on-line.
