A new magnetic Jeans instability in a nonuniform partially ionized plasma

A new magnetic Jeans type instability, which is due to the combined effects of the self-gravitational field and collisions of the electrons or the ions with stationary neutral atoms, is shown to exist in a partially ionized, self-gravitating, nonuniform magnetoplasma. The effect of the plasma number density inhomogeneity on this newly found instability is also examined, and it is found here that this effect does not only modify the dispersion properties of such a purely growing dissipative mode, but also introduces a real frequency in the latter. The present investigation may be of relevance to the formation of stars in galaxies via the fragmentation of partially ionized plasma systems, like interstellar molecular clouds. (orig.)