MHD Turbulent Mixing Layers: Equilibrium Cooling Models

Abstract

We present models of turbulent mixing at the boundaries between hot (T~10^{6-7} K) and warm material (T~10^4 K) in the interstellar medium, using a three-dimensional magnetohydrodynamical code, with radiative cooling. The source of turbulence in our simulations is a Kelvin-Helmholtz instability, produced by shear between the two media. We found, that because the growth rate of the large scale modes in the instability is rather slow, it takes a significant amount of time (~1 Myr) for turbulence to produce effective mixing. We find that the total column densities of the highly ionized species (C IV, N V, and O VI) per interface (assuming ionization equilibrium) are similar to previous steady-state non-equilibrium ionization models, but grow slowly from log N ~10^{11} to a few 10^{12} cm^{-2} as the interface evolves. However, the column density ratios can differ significantly from previous estimates, with an order of magnitude variation in N(C IV)/N(O VI) as the mixing develops.

10 pages, 10 Figures (2 in color), Accepted for publication on Astrophysical Journal

References in corpus (10)

• HARM: A Numerical Scheme for General Relativistic Magnetohydrodynamics
• Thermal Conduction in Clusters of Galaxies
• Compressible Sub-Alfvenic MHD turbulence in Low-beta Plasmas
• Distribution and Kinematics of O VI in the Galactic Halo
• Enhancement and suppression of heat transfer by MHD turbulence
• Thermal Conduction in Magnetized Turbulent Gas
• A Survey of OVI Absorption in the Local Interstellar Medium
• OVI, NV, and CIV in the Galactic Halo: I. Velocity-Dependent Ionization Models
• OVI, NV and CIV in the Galactic Halo: II. Velocity-Resolved Observations with Hubble and FUSE
• A Useful Approximation to the Cooling Coefficient of Trace Elements

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