| Abstract | The field containing the Irregular V galaxy DDO 13, which appears to form a bound system with UGC 1171 and another small feature, Dw 0137 + 1541, has been mapped in the hydrogen line. DDO 13 has a well-developed H I disk which shows evidence for a warp and nonplanar motions in the H I at the outer edge of the disk. The system shows the usual excess of binding mass above both the luminous mass and the dynamical masses derived for the individual galaxies from their rotations. If this system is bound to the nearby ScI NGC 628, the smaller galaxies may carry most of the angular momentum and be important participants in the evolution of NGC 628. |
