A study of fast time structure within cosmic gamma-ray bursts.
Abstract
Two gamma-ray bursts are studied on the basis of data recorded by a germanium spectrometer on board a low-altitude polar orbiting satellite and by gamma-ray sensors on board the Vela satellite. For the event of Dec. 18, 1972, the data indicate that at least five microbursts occurred within 1.8 sec. There is also evidence for three more time-structured features at later times. The spectrum showed a generally increasing hardness at the beginning of the event, but during microbursts, when the intensities were higher, the spectra did not differ significantly from those at neighboring times. The spectra at late times were much softer than those observed just prior to the main burst. For the December, 1972 event and for the event of July 21, 1973, the occurrence of microbursts was observed at various times throughout the events. The microburst structure of the July event was even more pronounced than in the December event.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- June 1975
- DOI:
- 10.1086/153649
- Bibcode:
- 1975ApJ...198..717I
- Keywords:
-
- Cosmic Rays;
- Fine Structure;
- Gamma Rays;
- Satellite Observation;
- Time Dependence;
- Black Body Radiation;
- Germanium;
- Polar Orbits;
- Radiation Measurement;
- Scintillation Counters;
- Spectrometers;
- Vela Satellites;
- Space Radiation