Pulsations in solar hard X-ray bursts.
Abstract
We have analyzed the hard X-ray emission from 28 large solar events, searching for pulsations in intensity profiles. Periodicity occurred in 26 events, usually soon after the onset, with periods in the range 10-100 s. Pulsations occurring at common frequencies in different energy bands are observed to be closely in phase. Periodic behavior in hard X-ray emission is related to that at microwave and decametric wavelength. We discuss our observations briefly in terms of two models: that of McClean et al. (1971), applied to X-ray emission, and that of Brown and Hoyng (1975). As periodicity is normal in extended hard X-ray bursts and occurs through a broad energy band, it is probably directly related to a principal flare acceleration mechanism. Our observations constrain possible mechanisms of flare acceleration and physical properties of the acceleration region.
- Publication:
-
Solar Physics
- Pub Date:
- March 1978
- DOI:
- 10.1007/BF00152054
- Bibcode:
- 1978SoPh...57..191L
- Keywords:
-
- Pulsed Radiation;
- Satellite-Borne Instruments;
- Solar X-Rays;
- X Ray Spectra;
- Bursts;
- Energy Bands;
- Fourier Analysis;
- Oso-5;
- Power Spectra;
- Solar Flares;
- X Ray Telescopes;
- Solar Physics;
- Microwave;
- Flare;
- Energy Band;
- Intensity Profile;
- Periodic Behavior;
- Solar X Rays:Bursts