On the angular momentum of colliding interstellar clouds

Limits are determined for the angular velocity and momentum change resulting from the cumulative and binary collisions of spherical clouds. Due to the braking effects of the galactic magnetic field and of partially elastic motions during cloud collisions, the angular momenta obtained are generally unattainable uppermost limits. The expected changes of rotation rates are several orders of magnitude larger for interstellar clouds and protostellar fragments of low mass, in comparison to large-mass clouds. Due to the large angular momentum changes, cloud collisions could be responsible for some observed random orientations of interstellar cloud rotation axis inclinations, and for the random orientations of stars.