Relationship between hard X-ray and EUV sources in solar flares.
Abstract
The high time resolution hard X-ray (not less than 15 keV) observations of medium and large impulsive solar flares made with the OSO 5 satellite are compared with the simultaneous ground-based observations of 10-1030 A EUV flux made via sudden frequency deviations (SFD) at Boulder. For most flares the agreement between the times of maxima of the impulsive hard X-ray and EUV emissions is found to be consistent with earlier studies (not less than 1 s). The rise and decay times of the EUV emission are larger than the corresponding times for X-rays not less than 30 keV. When OSO 5 hard X-ray measurements are combined with those made by OGO1, OGO 3, OGO 5, and TD 1A satellites, it is found that there is a nearly linear relationship between the energy fluxes of impulsive EUV emission and X-rays not less than 10 keV over a wide range of flare magnitudes. A model involving only a 'partial precipitation' of energetic electrons and consisting of both thick and thin target hard X-ray sources is examined.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- December 1979
- DOI:
- 10.1086/157544
- Bibcode:
- 1979ApJ...234..669K
- Keywords:
-
- Far Ultraviolet Radiation;
- Solar Flares;
- Solar X-Rays;
- X Ray Astronomy;
- Electron Energy;
- Emission Spectra;
- Oso-5;
- Photons;
- Solar Electrons;
- Solar Radio Bursts;
- Universal Time;
- X Ray Sources;
- Solar Physics;
- Extreme UV:Solar Flares;
- Solar Flares:X Rays