| Abstract | Results of a 21-cm hydrogen line study of NGC 5668, obtained with the 300-foot radio telescope, are presented The measured systemic velocity is 1577 I 30 km/s, and represents the highest velocity thus far detected in the 21-cm line of neutral hydrogen. This velocity is in reasonably good agreement with the optically derived value. Optical versus 21-cm determinations of cA /X0 are now available for a total velocity range of 1920 km/s (from -343 to +1577 km/s) and confirm the constancy of cA /X0 for a wavelength ratio of 5 X 100:1. The hydrogen content and total mass are evaluated; the fractional content of neutral atomic hydrogen in terms of the total mass is 0 077, a value consistent with the structural type of NGC 5668. |
