| Abstract | We have used the Nançay Radio Telescope to obtain new global H I data for 16 giant low surface brightness (LSB) galaxies. Our targets have optical luminosities and disk scale lengths at the high end for spiral galaxies (LB~1010 Lsun and h_r>~ 6 kpc for H0=75 km s-1 Mpc-1), but they have diffuse stellar disks, with mean disk surface brightnesses ga 1 magnitude fainter than normal giant spirals. Thirteen of the galaxies previously had been detected in H I by other workers, but the published H I observations were either confused, resolved by the telescope beam, of low signal-to-noise, or showed significant discrepancies between different authors. For the other 3 galaxies, no H I data were previously available. Several of the galaxies were resolved by the Nançay \am{3}{6} E-W beam, so global parameters were derived from multiple-point mapping observations. Typical H I masses for our sample are >~ 1010 M_sun, with M_HI/LB=0.3-1.7 (in solar units). All of the observed galaxies have published optical surface photometry, and we have compiled key optical measurements for these objects from the literature. We frequently find significant variations among physical parameters of giant LSB galaxies reported by various workers. Tables 2 and 4 are only available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/365/1 Figure 2 and Tables 3, 5 and 6 are only available in electronic form at http://www.edpsciences.org |
