Chandra Deep Field South. 1 Ms catalog

The flux limits at the aimpoint for the soft (0.5-2keV) and hard (2-10keV) bands are 5.5x10^-17^erg/s/cm^2^ and 4.5x10^-16^erg/s/cm^2^, respectively. The total number of sources is 346; out of them, 307 were detected in the 0.5-2keV band, and 251 in the 2-10keV band. We also present optical identifications for the catalogued sources.

Our primary optical data are R band imaging from VLT/FORS1 to a depth of R~26.5 (Vega). In regions of the field not covered by the VLT/FORS1 deep imaging, we use R-band data obtained with the Wide Field Imager (WFI) on the ESO-MPI 2.2 m telescope, as part of the ESO Imaging Survey (EIS), which cover the entire X-ray survey. We found that the FORS1/Chandra offsets are small, ~1".

Coordinate cross-correlation finds 85% of the Chandra sources covered by FORS1 R to have counterparts within the 3{sigma} error box (>~1.5" depending on off-axis angle and X-ray signal-to-noise). The unidentified fraction of sources, approximately ~10%-15%, is close to the limit expected from the observed X-ray flux to R-band ratio distribution for the identified sample.