Energetic particles in the solar atmosphere
Abstract
The Sun is an efficient particle accelerator. These particles play a major role in the active Sun because they contain a large amount of the magnetic energy released during flares. Energetic electrons and ions interact with the solar atmosphere and produce high-energy X-rays and γ-rays. Energetic particles can also escape to the corona and interplanetary medium and may eventually reach the Earth's orbit. It is currently admitted that solar flares are powered by magnetic energy previously stored in the coronal magnetic field and that magnetic energy release is likely to occur on coronal current sheets along regions of strong gradient of magnetic connectivity. Particle transport from the acceleration region to the emission sites must also be considered to infer properties of the accelerated particles (and thus of the acceleration processes) from the observations of their radiation. In this paper, we will present the results of some recent studies using RHESSI observations: relationship found in some flares between ribbons of electric currents observed at the photospheric level and the flare energetic electrons traced by their X-ray emissions. We will also present some results on electron transport in solar flares and comment on the role of scattering in this process. We will finally describe some recent results from FERMI/LAT observations on the production of GeV protons in connection with solar flares and/or coronal mass ejections.
- Publication:
-
SF2A-2019: Proceedings of the Annual meeting of the French Society of Astronomy and Astrophysics
- Pub Date:
- December 2019
- Bibcode:
- 2019sf2a.conf..283V
- Keywords:
-
- Sun;
- Solar Flares;
- Energetic Particles;
- X-ray;
- γ-ray;
- RHESSI;
- FERMI/LAT