Ambipolar Diffusion-mediated Thermal Fronts in the Neutral Interstellar Medium

Type Journal Article
Names Jennifer M. Stone, Ellen G. Zweibel
Publication The Astrophysical Journal
Volume 724
Issue 1
Pages 131-139
Date November 1, 2010
Library Catalog NASA ADS
Abstract In a thermally bistable medium, cold, dense gas is separated from warm, rarefied gas by thin phase transition layers, or fronts, in which heating, radiative cooling, thermal conduction, and convection of material are balanced. We calculate the steady-state structure of such fronts in the presence of magnetic fields, including the processes of ion-neutral drift and ion-neutral frictional heating. We find that ambipolar diffusion efficiently transports the magnetic field across the fronts, leading to a flat magnetic field strength profile. The thermal profiles of such fronts are not significantly different from those of unmagnetized fronts. The near uniformity of the magnetic field strength across a front is consistent with the flat field strength-gas density relation that is observed in diffuse interstellar gas.
Tags ISM: structure, Magnetohydrodynamics: MHD, Methods: Numerical, diffusion
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