Nonpotential Magnetic Fields at Sites of Gamma-Ray Flares
Abstract
The relation between the degree of nonpotentiality of photospheric magnetic fields and the occurrence of gama-ray flares is examined to determine whether there are special signatures of the stressed fields for this type of flare. Observations of the flares in the active region of April 1984 (AR 4474) are analyzed, showing that the big flare initiated at the location on the magnetic neutral line where the field deviated the most from a potential field. The nonpotential signatures of AR 4474 are compared with those of four other regions. The results suggest that gamma-ray flares are associated with strongly nonpotential fields that extend over relatively larger lengths of the magnetic neutral line that the fields associated with flares that do not produce gamma-ray events.
- Publication:
-
The Astrophysical Journal Supplement Series
- Pub Date:
- June 1990
- DOI:
- 10.1086/191447
- Bibcode:
- 1990ApJS...73..159H
- Keywords:
-
- Gamma Ray Bursts;
- Solar Flares;
- Solar Magnetic Field;
- Field Strength;
- Gamma Ray Spectra;
- Lines Of Force;
- Photosphere;
- Solar Physics;
- GAMMA RAYS: GENERAL;
- HYDROMAGNETICS;
- RADIATION MECHANISMS;
- SUN: FLARES