Astron. Astrophys. Suppl. Ser. 141, 257-283

ISOCAM observations of the very deep IRAS 60 micron sample in the NEP region

I. The data

H. Aussel¹ - D. Coia² - P. Mazzei ¹ - G. De Zotti¹ - A. Franceschini²

Send offprint request: G. De Zotti,
e-mail: dezotti@pd.astro.it

1 - Osservatorio Astronomico di Padova, Vicolo dell'Osservatorio 5, I-35122 Padova, Italy
2 - Dipartimento di Astronomia dell'Università di Padova, Vicolo dell'Osservatorio 5, I-35122 Padova, Italy

Received September 10; accepted October 26, 1999

Abstract:

We present the results of ISO observations with the CAM LW3 filter, centered at $\lambda_{\rm eff} = 14.3\,\mu$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 $\geq 3$ and 69 with $S/N\geq 5$ in the $3.2'\times 3.2'$ fields centered on the nominal positions of IRAS sources. Sixty-five $\geq 3\sigma$ detections (49 of which at $\geq 5\sigma$) are likely identifications of IRAS sources. Ten additional IRAS sources have possible $\geq 3\sigma$ ISOCAM counterparts. In 6 further cases, signals at the $2-3\sigma$ 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 $\geq 5\sigma$, with $S(14.3~\mu{\rm m}) \geq 3.5$ mJy. The corresponding areal density is consistent with that found in previous surveys. Finding charts for all observed fields are given.

Key words: surveys -- galaxies: photometry -- galaxies: starburst -- infrared: galaxies