H I observations of galaxies behind the Milky Way in the Puppis region |
| |
| Authors: | Pierre Chamaraux Jean-Louis Masnou Ilya Kazés Mamoru Sait&#; Tadafumi Takata Toru Yamada |
| |
| Institution: | Arpèges, Observatoire de Paris, Section de Meudon, 92195 Meudon Cedex, France;Observatoire de Bordeaux, Universitéde Bordeaux 1, B.P. 89 33270 Floirac, France;DARC, Observatoire de Paris, Section de Meudon, 92195 Meudon Cedex, France;Department of Astronomy, Faculty of Science, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan; Subaru Telescope, National Astronomical Observatory of Japan, 650 N. A'ohoku Place, Hilo, Hawaii 96720, USA; Astronomical Institute, Tohoku University, Aoba, Sendai 980-8578, Japan |
| |
| Abstract: | We report 21-cm H i 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 H I 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 H I 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 H I 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 ( AB 2.3), or have a very small diameter, lower than 0.5 arcmin. |
| |
| Keywords: | galaxies: distances and redshifts radio lines: galaxies |
|
|
