Ion dynamics and gravitational instability of a dusty plasma

The gravitational instability of a dusty plasma with ion dynamics taken into account is studied. For the range of parameters relevant to planetary rings and interstellar media: we demonstrate that the inclusion of ion dynamics cannot cause additional destabilization of a gravitating dusty plasma system. Streaming of the cold ions, on the other hand; enhances the Jeans condensation of a dusty plasma. Consistency of the results with previous work and new aspects arising owing to consideration of ion dynamics is discussed.