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| Paper: |
Spectral Methods for Modeling Local Interstellar Turbulent Flows |
| Volume: |
359, Numerical Modeling of Space Plasma Flows: Astronum-2006 |
| Page: |
91 |
| Authors: |
Shaikh, D.; Pogorelov, N.V.; Zank, G.P. |
| Abstract: |
A local interstellar turbulence model is developed based on self-consistent two-dimensional fluid simulations. The model describes a partially ionized magnetofluid interstellar medium (ISM) that couples a neutral hydrogen fluid with a plasma primarily through charge exchange interactions, and assumes that the ISM turbulent correlation scales are much bigger than the shock characteristic length-scales. Charge exchange interactions occur ubiquitously in warm ISM plasmas in a subtle nonlinear manner whose strength depends largely on the relative speed between the plasma and the neutral fluid. Unlike small length-scale linear collisional dissipation in the fluid, charge exchange processes can be effective on a variety of ISM length-scales depending upon the neutral and plasma densities, charge exchange cross section and the characteristic length scales. We find, from scaling arguments and nonlinear coupled fluid simulations, that charge exchange interactions modify spectral transfer associated with largescale energy containing eddies. Consequently, the warm ISM turbulent cascade rates are faster than those predicted by Kolmogorov's phenomenology. |
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