Numerical Simulation of Cosmic Rays Effects on the Structure of the Heliosphere
Abstract
The heliopause is a pressure balanced structure that separates the inner and outer heliosheaths. The total pressure of the solar wind particles, including pickup ions and anomalous cosmic rays (ACRs), is approximately equal to the pressure of the interstellar gas and its magnetic field on the outer side. Should one of the pressures change, the heliosphere will shrink or expand in response, to compensate for the imbalance and reach a new equilibrium state. Based on Voyager 1 observations, some ACRs may have crossed the heliopause and escaped into the interstellar medium, providing a mechanism of energy transfer between the inner and outer heliosheaths that is not included in conventional MHD models. Here we evaluate the effect of ACR escape on the size and shape of the heliosphere using a simple model that includes the additional momentum and energy flux terms across the heliopause. We show that this effect could be a possible explanation for the unexpectedly early heliopause encounter by Voyager 1.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2016
- Bibcode:
- 2016AGUFMSH31A2543G
- Keywords:
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- 2126 Heliosphere/interstellar medium interactions;
- INTERPLANETARY PHYSICSDE: 2164 Solar wind plasma;
- INTERPLANETARY PHYSICSDE: 7837 Neutral particles;
- SPACE PLASMA PHYSICSDE: 7845 Particle acceleration;
- SPACE PLASMA PHYSICS