Stereoscopic Observations of a Solar Flare Hard X-Ray Source in the High Corona
Abstract
The vertical structure of the impulsive and gradual hard X-ray sources in high coronae and the characteristics of the impulsive soft X-ray emission are investigated on the basis of PVE, ICE, and GOES observations of the energetic flare on February 16, 1984. The average photon spectra observed by these instruments during the impulsive and gradual hard X-ray bursts are summarized. A comparison of these unocculted and partially occulted spectra shows that the sources of the impulsive hard X-ray (greater than about 25 keV) and impulsive soft X-ray (2-5 keV) emissions in this flare extended to coronal altitudes greater than about 200,000 km above the photosphere. At about 100 keV, the ratio of the coronal source brightness to the total source brightness was 0.001 during the impulsive phase and less than about 0.01 during the gradual hard X-ray burst. The sources of the gradual hard X-ray burst and gradual soft X-ray burst were almost completely occulted, indicating that these sources were located at heights less than 200,000 km above the photosphere.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- May 1992
- DOI:
- 10.1086/171320
- Bibcode:
- 1992ApJ...390..687K
- Keywords:
-
- Gamma Ray Bursts;
- Solar Corona;
- Solar Flares;
- Solar X-Rays;
- X Ray Sources;
- Gamma Ray Astronomy;
- Spaceborne Astronomy;
- Stereoscopy;
- X Ray Astronomy;
- X Ray Spectra;
- Solar Physics;
- SUN: CORONA;
- SUN: FLARES;
- SUN: X-RAYS;
- GAMMA RAYS