Instabilities of inhomogeneous plasmas streaming relative to inhomogeneous dust distributions

Abstract

Streaming instabilities are studied for an inhomogeneous distribution of dust particles. Such situations are characteristic of stellar neighbourhoods, where the star's plasma wind ploughs through a surrounding dust shell. This should result in the acceleration of dust particles at the expense of the plasma momentum, which may throw light on certain dynamical features of the dust cloud vis-à-vis the plasma dynamical features. Streaming instabilities are a first step towards such a study. Various cases of the relative magnitudes of the plasma and dust velocities are analysed, and the role of inhomogeneities is highlighted.