On nonideal MHD properties of the partially ionized interstellar gas

Abstract

The counterflow configuration resulting from the motion of the heliosphere through the ambient interstellar medium meanwhile has been described by several hydrodynamic and magnetohydrodynamic (MHD) model approaches. The self-consistent inclusion of interstellar and solar magnetic fields in presently existing MHD approaches has been achieved assuming the validity of ideal magnetohydrodynamics where frozen-in magnetic field condition is fulfilled. This assumption is valid only, however, if the electrical Conductivity of plasma is very high (i.e., magnetic Reynolds number Rem, ≫1). As we are going to show here, the presence of neutral H atoms in the interstellar medium strongly questions this requirement and leads to a nonideal Ohm's law invalidating the frozen-in field condition. The MHD modeling of the heliospheric interface thus has to be carried out on a new basis presented in this paper. Copyright 2003 by the American Geophysical Union.