Fermi Detection of γ-Ray Emission from the M2 Soft X-Ray Flare on 2010 June 12
Abstract
The Geostationary Operational Environmental Satellite (GOES) M2-class solar flare, SOL2010-06-12T00:57, was modest in many respects yet exhibited remarkable acceleration of energetic particles. The flare produced an ~50 s impulsive burst of hard X- and γ-ray emission up to at least 400 MeV observed by the Fermi Gamma-ray Burst Monitor and Large Area Telescope experiments. The remarkably similar hard X-ray and high-energy γ-ray time profiles suggest that most of the particles were accelerated to energies gsim300 MeV with a delay of ~10 s from mildly relativistic electrons, but some reached these energies in as little as ~3 s. The γ-ray line fluence from this flare was about 10 times higher than that typically observed from this modest GOES class of X-ray flare. There is no evidence for time-extended >100 MeV emission as has been found for other flares with high-energy γ-rays.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- February 2012
- DOI:
- 10.1088/0004-637X/745/2/144
- arXiv:
- arXiv:1111.7026
- Bibcode:
- 2012ApJ...745..144A
- Keywords:
-
- acceleration of particles;
- Sun: flares;
- Sun: particle emission;
- Sun: X-rays;
- gamma rays;
- Astrophysics - High Energy Astrophysical Phenomena;
- Astrophysics - Solar and Stellar Astrophysics
- E-Print:
- 27 pages, 7 figures. Corresponding Authors: M. S. Briggs, michael.briggs@nasa.gov