KINETIC VERSUS MULTI-FLUID APPROACH FOR INTERSTELLAR NEUTRALS IN THE HELIOSPHERE: EXPLORATION OF THE INTERSTELLAR MAGNETIC FIELD EFFECTS

We present a new three-dimensional (3D) self-consistent two-component (plasma and neutral hydrogen) model of the solar wind interaction with the local interstellar medium (LISM). This model (K-MHD) combines the magnetohydrodynamic treatment of the solar wind and the ionized LISM component with a kinetic model of neutral interstellar hydrogen (LISH). The local interstellar magnetic field (B-LISM) intensity and orientation are chosen based on an early analysis of the heliosheath flows. The properties of the plasma and neutrals obtained using the K-MHD model are compared to previous multi-fluid and kinetic models. The new treatment of LISH revealed important changes in the heliospheric properties not captured by the multi-fluid model. These include a decrease in the heliocentric distance to the termination shock (TS), a thinner heliosheath, and a reduced deflection angle (0) of the heliosheath flows. The asymmetry of the TS, however, seems to be unchanged by the kinetic aspect of the LISH.