First DENIS I-band extragalactic catalog

This paper presents the rst I-band photomet- ric catalog of the brightest galaxies extracted from the Deep Near Infrared Survey of the Southern Sky (DENIS) An automatic galaxy recognition program has been de- veloped to build this provisional catalog. The method is based on a discriminating analysis. The most discrimi- nant parameter to separate galaxies from stars is proved to be the peak intensity of an object divided by its ar- ray. Its eciency is better than 99%. The nominal ac- curacy for galaxy coordinates calculated with the Guide Star Catalog is about 6 arcsec. The cross-identication with galaxies available in the Lyon-Meudon Extragalactic DAtabase (LEDA) allows a calibraton of the I-band pho- tometry with the sample of Mathewson et Al. Thus, the catalog contains total I-band magnitude, isophotal di- ameter, axis ratio, position angle and a rough estimate of the morphological type code for 20260 galaxies. The internal completeness of this catalog reaches magnitude Ilim =1 4 :5, with a photometric accuracy of 0:18 m. 25% of the Southern sky has been processed in this study. This quick look analysis allows us to start a radio and spectrographic follow-up long before the end of the survey.