Modeling of the Heliospheric Interface, Magnetic Field, and Cosmic‐Ray Transport

Abstract

Magnetized flow and cosmic-ray transport in the local astrosphere are studied. A hybrid numerical model is used to calculate the heliospheric interface, the heliospheric magnetic field, and cosmic-ray modulation. Assuming that the transport parameters scale inversely proportional to the magnetic field, the amplification of the field in the inner helio-sheath results in a sudden decrease of these parameters over the shock. This, together with our model calculations showing the compressed and heated solar wind flow is not divergence-free in the postshock region, results in effective adiabatic acceleration of cosmic-ray particles in the heliosheath. In particular, the peak of the computed anomalous particles is not at the shock but some distance into the inner heliosheath, where this region becomes populated with relatively high intensities of heated anomalous particles. However, this effect is largely dependent on the values of the transport parameters in the heliosheath. It is also shown that an improvement in the kinematically transported helio-spheric magnetic field leads to a significantly different spatial distribution of cosmic rays compared to a Parker model. © 2007. The American Astronomical Society. All rights reserved.