Clouds and holes: Self-organization in compressible fluid and collisionless plasma turbulence

Abstract

A simple physical model which describes the dynamics of turbulence and the spectrum of density fluctuations in compressible, self-gravitating matter and self-binding, phase-space density fluctuations is presented. The two systems are analogous to each other in that each tends to self-organize into hierarchical structures via the mechanism of Jeans collapse. Predictions of the model for velocity-dispersion-density-length-scale correlations and morphology of molecular clouds are in good agreement with observational evidence. In the case of collisionless plasmas, the model exhibits interesting geometric properties such as intrinsic intermittency and anisotropy, and explains several features of numerical simulations.