Diagnosing Magnetic Fields in Partially-Ionised Astrophysical Plasmas

摘要

We present a computational model of a partially-ionised plasma as a mixture of two fluids: an MHD plasma and a neutral gas. We find that the momentum coupling between the plasma and the neutral gas leads to complex interactions between the two fluids. This means that the normal wave modes of each independent fluid are modified to produce a combined, hybrid response, with the intriguing possibility that neutral gas can not only respond indirectly to magnetic fluctuations but also generate them via sound waves. The significance of this may lie in the remote sensing of magnetic perturbations, with particular relevance to the Chandrasekhar-Fermi method for inferring interstellar magnetic fields.