H I observations of galaxies behind the Milky Way in the Puppis region

We report 21-cm HI line observations of 161 galaxies located behind the Milky Way, in the Puppis region. The observations have been carried out with the Nançay radio telescope, resulting in 101 detections. Most of the galaxies observed appear in the ESO catalogue, and present apparent diameters larger than 1.6 arcmin. We show that the detection rate is strongly related to the apparent diameter; it is as high as 76 per cent for diameters larger than 1.6 arcmin. Half of the non-detections result, in fact, from an insufficient velocity coverage. Global parameters of the detected galaxies are computed, after a careful discussion of the correction for Galactic absorption. Our HI data are then compared with those obtained by Kraan-Korteweg & Huchtmeier with the Effelsberg radio telescope for 20 galaxies observed in common: the agreement is excellent, implying respective uncertainties on recession velocities and on HI fluxes lower than 10 km s^-1 and 2 Jy km s^-1 on average. Finally, we find that the detected galaxies follow well the correlation between the optical linear diameter and the HI mass found by Haynes & Giovanelli. This result shows that our diameter corrections for Galactic absorption AB are quite good, except for eight objects which are heavily obscured (A_B > 2.3), or have a very small diameter, lower than 0.5 arcmin.