Rotation and Other Motions of the Magellanic Clouds from Radio Observations

Abstract

The radial velocities measured in a survey of the 21 cm line from the Magellanic Clouds are discussed, principally in terms of the median velocity for each line profile. It is shown that each Cloud is rotating, and the analysis confirms the view, based on optical evidence, that the Clouds are flattened and tilted systems. The gas is probably the least flattened constituent of each Cloud and shows a large decrease of rotational speed with increasing distance from the equatorial plane.