Simple Analytical Model for High Energy Power-Laws in Flare Spectra
Abstract
The mechanism that accelerates particles to the energies required to produce the observed spectra in solar flares is not well understood. Here, we propose a simple analytical, first-principle-based model that produces energy spectra with power-laws at high energies. This model is based on ideas from our previous semi-analytical model (Guidoni et. al 2016), which uses contracting magnetic islands (accelerators) formed during fast reconnection in simulated solar flares to accelerate electrons, as first proposed by Drake et al. (2006) for kinetic-scale plasmoids. We model particles visiting a handful number n of accelerators, each of which increases particles' energies by a relatively small amount. For simplicity, all accelerators have the same average number of particles, life-time, and efficiency e to accelerate particles. We assume that only a small fraction f of the particles in one accelerator is transferred between accelerators. The spectral index and the high-energy cutoff of the final distribution of particles can be related to our parameters n, f, and e. The goal of this simple model is to reduce a very complex problem to basic physics, not to reproduce observed events in detail.
- Publication:
-
Solar Heliospheric and INterplanetary Environment (SHINE 2018)
- Pub Date:
- July 2018
- Bibcode:
- 2018shin.confE.133G