| Abstract | H iline profiles, together with derived redshifts and integral properties, are presented for 46 Scd galaxies. The profile shapes are quite regular, with a double-peaked structure characteristic of galaxies with flat rotation curves. The ratios Ma 1/MT and MHi/Lpg, which are known to vary with Rubble type, have observed dispersions of I 80 percent within this classification, with intrinsic dispersions being probably less than I 50 percent. This establishes that integral property ratios are substantially homogeneous within the Scd classification. No indication of H I optical-depth effects with inclination is observed. Evidence is presented that distances derived solely from redshifts have an average uncertainty of <0.8 mag in the distance modulus. Subject headings: galaxies, motion in - galaxies, stellar content of - redshifts - 21-cm radiation |
