A new component of hard X-rays in solar flares
Abstract
High-resolution (approximately 1 keV FWHM) spectral measurements from 13 to 300 keV of a solar flare hard X-ray burst observed on 1980 June 27 by a balloon-borne array of cooled germanium planar detectors are presented. At energies below about 35 keV, a new component of solar flare hard X-rays is identified. This component is characterized by an extremely steep spectrum which fits closely to that from a Maxwellian electron distribution with a maximum temperature of about 34 x 10 to the 6th K and an emission measure of 2.9 x 10 to the 48th per cu cm. This hot isothermal component appears at the peak of the normal power-law-like impulsive X-ray burst component, and it remains isothermal and dominates the X-ray emission below about 30 keV through the decay of the flare event.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- December 1981
- DOI:
- 10.1086/183704
- Bibcode:
- 1981ApJ...251L.109L
- Keywords:
-
- Solar Flares;
- Solar X-Rays;
- X Ray Spectra;
- Balloon-Borne Instruments;
- Electron Distribution;
- High Resolution;
- Solar Activity Effects;
- Spectral Resolution;
- Solar Physics