Electron Acceleration by Multi-Island Coalescence
Abstract
Energetic electrons of up to tens of MeV are created during explosive phenomena in the solar corona. While many theoretical models consider magnetic reconnection as a possible way of generating energetic electrons, the precise roles of magnetic reconnection during acceleration and heating of electrons still remain unclear. Here we show from 2D particle-in-cell simulations that coalescence of magnetic islands that naturally form as a consequence of tearing mode instability and associated magnetic reconnection leads to efficient energization of electrons. The key process is the secondary magnetic reconnection at the merging points, or the `anti-reconnection', which is, in a sense, driven by the converging outflows from the initial magnetic reconnection regions. By following the trajectories of the most energetic electrons, we found a variety of different acceleration mechanisms but the energization at the anti-reconnection is found to be the most important process. We discuss possible applications to the energetic electrons observed in the solar flares. We anticipate our results to be a starting point for more sophisticated models of particle acceleration during the explosive energy release phenomena.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2010
- Bibcode:
- 2010AGUFMSH33A1812O
- Keywords:
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- 7514 SOLAR PHYSICS;
- ASTROPHYSICS;
- AND ASTRONOMY / Energetic particles;
- 7526 SOLAR PHYSICS;
- ASTROPHYSICS;
- AND ASTRONOMY / Magnetic reconnection;
- 7835 SPACE PLASMA PHYSICS / Magnetic reconnection;
- 7845 SPACE PLASMA PHYSICS / Particle acceleration