Gasdynamical calculations of preferred planes in prolate and triaxial galaxies. II: The case of a tumbling potential

Galactic gas motion in tumbling prolate and triaxial potentials is investigated. The presence of preferred planes predicted from studies of precession trajectories is confirmed, except for the preferred plane for the prograde gas ring normal to the tumbling axis. Some retrograde gas rings settle into tilted, warped, preferred planes. Prograde gas rings are disturbed in elongated prolate potentials, and some part of a gas ring concentrates in the galactic center. The time scale for gas to settle into the preferred plane is the time during which each part of a gas ring becomes wound up due to differential precession. If the potential of the polar ring galaxy is spherically symmetric, the polar ring is stable. 36 references.