Density Spectrum in the Diffuse Interstellar Medium and Solar Wind

Abstract

Inertial range turbulence properties are investigated for nearly incompressible density fluctuations using two-dimensional nonlinear fluid simulations. We find that density fluctuations behave as a passive scalar and do not satisfy the pseudosound approximation. As a result, the density fluctuations follow a Kolmogorov-like spectrum, and this is a possible explanation for the observed diffuse interstellar and solar wind density fluctuation spectrum.