Plasma flow in vicinity of the heliopause stagnation point in the presence of hydrogen neutral atoms

Abstract

Plasma flow in the solar wind/interstellar medium interaction region consists of two shock layers bounded by the termination and bow shocks and separated by the heliopause. It is usually accepted that the heliopause is a tangential discontinuity, where the plasma velocity, density and temperature have a jump. It is known that the charge exchange between hydrogen atoms penetrating in the interaction region from the interstellar medium and the plasma protons can strongly affect the flow structure in this region. The analytic description of the plasma flow in the nose part of the heliopause, in the vicinity of the stagnation point, is presented in this paper. It is shown that taking into account of two effects, the charge exchange between protons and neutral (hydrogen) atoms, and the plasma compressibility, modifies the flow structure near the stagnation point to an extent that the plasma density and temperature become continuous at the heliopause. The modified flow structure can significantly change the formulation and the study of the heliopause stability problem. Moreover, if this structure is stable, it can be used for the predicting and interpretation of the plasma parameters data near the heliopause.