Neutral hydrogen absorption in the double galaxy UGC 6081.

Hydrogen-line absorption at 21 cm has been detected in UGC 6081, a double system of galaxies. The absorption profile which consists of at least two components has a total velocity width of 355 km s^-1. The component where maximum absorption occurs has a half-width of 92 km s^-1, a midpoint radial velocity of 10817 km s^-1, and an optical depth of greater than 0.50. There is good agreement between the radial velocity of this feature and the optical velocity of the face-on galaxy in the pair. A strong radio source has been detected at a position coincident with the nucleus of the face-on companion. The large H I velocity dispersion, inconsistent with the kinematics of gas along the rotational axis of a normal spiral galaxy, together with the existence of a bright nuclear radio source in a double galaxy system, suggest that the two galaxies are closely interacting.