| Abstract | The neutral hydrogen properties of spiral galaxies have been measured at the Arecibo Observatory using a 21 cm spectral line system. One hundred and thirty galaxies were observed, and 101 have been detected and roughly mapped in H I. The data are used to derive the total mass of neutral hydrogen gas, the gravitational mass, and a Gaussian hydrogen diameter for some galaxies. A large scatter in H I diameters within each Hubble type is reported and Sc galaxies appear to have smaller H I diameters than Sb galaxies. Sb galaxies also show a strong tendency to have asymmetric H I distributions. The H I profile is measured with the width at 50% the peak flux, and comparisons are made with the Green Bank method. |
