Gas‐rich Dwarfs from the PSS‐II. III. H i Profiles and Dynamical Masses

We present Arecibo neutral hydrogen data on a sample of optically selected dwarf galaxies. The sample ranges in H I mass from 10 6 to 5 × 10 9 M ☉ , with a mean of 7.9 × 10 8 M ☉ . Using estimated H I radii, the H I surface densities range from 0.6 to 20 M ☉ pc -2 , all well below the critical threshold for star formation (Kennicutt 1998). M / L values of the LSB dwarfs range from 0.3 to 12 with a mean value of 2.0. Dynamical masses, calculated from the H I profile widths, range from 10 8 to 10 11 M ☉ . There is a strong correlation between optical luminosity and dynamical mass for LSB dwarfs implying that the dark matter (whether baryonic or nonbaryonic) follows the detectable baryonic matter.