Cosmic Rays Across the Rainbow Bridge: Particle Interactions in a Magnetized Plasma Atmosphere
Abstract
High-energy particles enter the solar atmosphere from Galactic or solar sources, producing gamma-ray "albedo'' radiations. These emissions come from the quiet Sun and from the large-scale corona, as well as from the vicinity of flares, and have been observed across a wide range of photon energies (MeV to GeV). The interaction of high-energy particles in the solar atmosphere depends essentially upon the joint variation of the magnetic field and the gas, and this has heretofore generally been characterized parametrically as P ~ Balpha (Zweibel & Haber 1983), with P the gas pressure and B the magnitude of the magnetic field. We have checked this relationship with a Bifrost 3D MHD model, approximating the particle transport as a guiding-center motion along "open'' (large-scale) fieldlines. We find alpha ~ 2.2 in the strongest (kG) fields in the simulation, but individual field structures have widely disparate relationships. The scatter corresponds to the strong meandering of the open-field flux tubes in the lower atmosphere and to their incessant dynamics. We discuss this and other aspects of the interactions of high-energy particles with the Sun (the "solar Størmer problem'').
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2019
- Bibcode:
- 2019AGUFMSH21B..02H
- Keywords:
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- 7514 Energetic particles;
- SOLAR PHYSICS;
- ASTROPHYSICS;
- AND ASTRONOMY;
- 7519 Flares;
- SOLAR PHYSICS;
- ASTROPHYSICS;
- AND ASTRONOMY;
- 7845 Particle acceleration;
- SPACE PLASMA PHYSICS;
- 7859 Transport processes;
- SPACE PLASMA PHYSICS