ESO imaging survey - Deep public survey: Multi-color optical data for the Chandra Deep Field South

This paper presents multi-passband optical data obtained from observations of the Chandra Deep Field South (CDF-S), located at 3 h 32 m , 2748 0 . The observations were conducted at the ESO/MPG 2.2 m telescope at La Silla using the 8k 8k Wide-Field Imager (WFI). This data set, taken over a period of one year, represents the rst eld to be completed by the ongoing Deep Public Survey (DPS) being carried out as a part of the ESO Imaging Survey (EIS) project. This paper describes the optical observations, the techniques employed for un-supervised pipeline processing and the general characteristics of the nal data set. Image processing has been performed using multi-resolution image decomposition techniques adapted to the EIS pipeline. The automatic processing steps include standard de-bias and flat-eld, automatic removal of satellite tracks, de-fringing/sky-subtraction, image stacking/mosaicking and astrometry. Stacking of dithered images is carried out using pixel-based astrometry which enables the ecient removal of cosmic rays and image defects, yielding remarkably clean nal images. The nal astrometric calibration is based on a pre-release of the GSC-II catalog and has an estimated intrinsic accuracy of <0.10 arcsec, with all passbands sharing the same solution. The paper includes data taken in six dierent lters (U 0 UBVRI). The data cover an area of about 0.25 square degrees reaching 5 limiting magnitudes of U 0 AB =2 6:0, UAB =2 5:7, BAB =2 6:4, VAB =2 5:4;RAB =2 5: 5a nd IAB = 24.7 mag, as measured within a 2FWHM aperture. The optical data covers an area of 0.1 square degrees for which moderately deep observations in two near-infrared bands are also available, reaching 5 limiting magnitudes of JAB 23: 4a ndKAB 22:6. The current optical/infrared data also fully encompass the region of the deep X-ray observations recently completed by the Chandra telescope. The optical data presented here, as well as the infrared data released earlier, are publicly available world-wide in the form of fully calibrated pixel and associated weight maps and source lists extracted in each passband. These data can be requested through the URL \http://www.eso.org/eis".