Effects of dust temperature and fast ions on gravitational instability in a self-gravitating magnetized dusty plasma

Abstract

A theoretical investigation has been made of effects of dust temperature, fast (nonthermal) ions, and external magnetic field on gravitational instability in a self-gravitating magnetized hot dusty plasma, which consists of extremely massive, negatively charged hot dust fluid, nonthermally distributed ions, and Boltzmann distributed electrons, where the gravitational force is comparable to or greater than the electrostatic force. The effects of dust temperature, fast ions, and external magnetic field have been found to modify the criterion for this gravitational instability. It has been shown that the growth rate of this gravitational instability decreases with dust temperature, fast ions, and external magnetic field, but increases with the number of free electrons, with the ratio of ion temperature to electron temperature, and with the ratio of dust mass to dust charge. The implications of this result in some astrophysical situations are briefly discussed.