Double galaxies. I. Observational data on a well-defined sample.

A sample including 279 binary galaxies over a wide range of separations is selected from the Uppsala general catalog using well-defined criteria. The true angular separation distribution of the binary galaxies is reconstructed from the observed distribution and a statistical analysis of the selection criteria. Observational data are compiled on the galaxies using optical as well as radio information. The associated 21 cm neutral-hydrogen studies result in the detection of 149 member galaxies (94 without observed optical redshifts). In addition to accurate radial velocities, H I studies provide global measurements on individual galaxies, including total indicative mass and mass-to-light ratios, to be compared with values obtained from a statistical study of the orbital parameters.