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Observing and data-mining with OmegaCAM

Edwin A. Valentijn, NOVA / Kapteyn Astronomical Institute, PO Box 800, NL-9700 AV Groningen, the Netherlands

E. Deul, Sterrewacht Leiden

OmegaCAM is an optical 16k × 16k camera, which is being build for the 2.6m VLT survey telescope on Paranal (VST). The camera images 1 square degree of the sky with a pixel size of 0.22 arcsec. OmegaCAM will be the only instrument for the VST, at least during the first 5 years of operations, which are expected to start during the summer of 2002.

OmegaCAM will be used at visual wavelengths with a wide variety of pass-bands and will be offered to the user community allowing the user to conduct his own defined programme. In order to efficiently archive and handle the huge amount of data (20-30 T-byte/year of raw data, 5 T-byte/year of persistent calibration data and 3-5 T-byte/year of astronomical source list data), the design of calibration and scientific data reduction procedures have focussed on developing standard observing scenarios and object oriented methods to handle the calibrations and the scientific data reduction, also supporting individual programmes.

The OmegaCAM/NOVA designs will be presented. These designs involve new balances between centralized processing and data archives and supporting the individual needs of the users.

The plans anticipate on national data-centers supporting individual researchers by providing parallel hardware, standard pipelines, object oriented database systems taking care of the administration of the calibrations. Flexibility for the data-mining of astronomical source lists is an important requirement, particularly the possibility for the re-derivations of the result allowing insight in the quality of the calibrations.