| Abstract | Results are presented for a simulation of 21-cm velocity profiles of spiral galaxies. The relation between profile widths and rotation curves is examined, and observed line widths for nearly 500 galaxies are analyzed. It is shown that because of a relation between intrinsic line width and absolute magnitude, the former, though independent of distance, is subject to the same selection effects as any distance-dependent property derived from a magnitude-limited sample. The dependence of intrinsic line width on galaxy type is also investigated. It is found that for samples of the same absolute magnitude, late-type galaxies have systematically smaller intrinsic line widths than early-type systems. |
