ISOCAM observations of the very deep IRAS 60 micron sample in the NEP region. I. The data

Abstract

We present the results of ISO observations with the CAM LW3 filter, centered at lambda_eff = 14.3 mu m, of 94 out of the 98 galaxies comprising the complete 60 mu m IRAS deep survey (IDS) sample in the north ecliptic polar region. In addition, we observed a source detected by IRAS at 25 mu m and found to have particularly interesting properties. Altogether, 106 sources were detected with a signal to noise ratio >= 3 and 69 with S/N>= 5 in the 3.2'x 3.2' fields centered on the nominal positions of IRAS sources. Sixty-five >= 3sigma detections (49 of which at >= 5sigma ) are likely identifications of IRAS sources. Ten additional IRAS sources have possible >= 3sigma ISOCAM counterparts. In 6 further cases, signals at the 2-3sigma level were detected close to the IRAS position. Indications that IRAS sources might actually be multiple (source confusion) were found in 4 IDS fields. On the whole, we confirm the reality of 69 to 90% of IDS sources. Appropriate statistical corrections for the bias affecting faint flux estimates were applied to ISOCAM data. Ten serendipitous sources were detected at >= 5sigma , with S(14.3 mum ) >= 3.5 mJy. The corresponding areal density is consistent with that found in previous surveys. Finding charts for all observed fields are given. Based on observations with the Infrared Space Observatory (ISO). ISO is an ESA project with instruments funded by ESA Member States (especially by the PI countries: France, Germany, The Netherlands and the United Kingdom) and with participation of ISAS and NASA.