HI observations of giant low surface brightness galaxies

We have used the Nancay Radio Telescope to obtain new global H-I data for 1 6 giant low surface brightness (LSB) galaxies. Our targets have optical lum inosities and disk scale lengths at the high end for spiral galaxies (L-B s imilar to 10(10) L-. and h(r) greater than or similar to 6 kpc for H-0 = 75 km s(-1) Mpc(-1)), but they have diffuse stellar disks, with mean disk sur face brightnesses greater than or similar to 1 magnitude fainter than norma l giant spirals. Thirteen of the galaxies previously had been detected in H -I by other workers, but the published H-I observations were either confuse d, resolved by the telescope beam, of low signal-to-noise, or showed signif icant discrepancies between different authors. For the other 3 galaxies, no H-I data were previously available. Several of the galaxies were resolved by the Nancay 3.'6 E-W beam, so global parameters were derived from multipl e-point mapping observations. Typical H-I masses for our sample are greater than or similar to 10(10) M-., with M-HI/L-B = 0.3 - 1.7 (in solar units). All of the observed galaxies have published optical surface photometry, an d we have compiled key optical measurements for these objects from the lite rature. We frequently find significant variations among physical parameters of giant LSB galaxies reported by various workers.