Explanatory Supplement of the ISOGAL-DENIS Point Source Catalogue

Abstract

We present version 1.0 of the ISOGAL-DENIS Point Source Catalogue (PSC), containing more than 100,000 point sources detected at 7 and/or 15 micron in the ISOGAL survey of the inner Galaxy with the ISOCAM instrument on board the Infrared Space Observatory (ISO). These sources are cross-identified, wherever possible, with near-infrared (0.8-2.2 micron) data from the DENIS survey. The overall surface covered by the ISOGAL survey is about 16 square degrees, mostly (95%) distributed near the Galactic plane (|b| < 1 deg), where the source extraction can become confusion limited and perturbed by the high background emission. Therefore, special care has been taken aimed at limiting the photometric error to ~0.2 magnitude down to a sensitivity limit of typically 10 mJy. The present paper gives a complete description of the entries and the information which can be found in this catalogue, as well as a detailed discussion of the data processing and the quality checks which have been completed. The catalogue is available via the VizieR Service at the Centre de Données Astronomiques de Strasbourg (CDS, http://vizier.u-strasbg.fr/viz-bin/VizieR/) and also via the server at the Institut d'Astrophysique de Paris (http://www-isogal.iap.fr/). A more complete version of this paper, including a detailed description of the data processing, is available in electronic form through the ADS service.