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Space-Borne Observations of Intense Gamma-Ray Flashes Above ThunderstormsIntense millisecond flashes of MeV photons were discovered with the space-borne detectors of the Burst and Transient Source Experiment (BATSE) aboard the Compton Gamma-Ray Observatory (CGRO). These flashes originate at altitudes above at least 30 km, in order to be observable by the orbiting detectors. Over the entire CGRO mission, from 1991 until 2000, about 70 of these events were observed. Nearly all TGFs had short (millisecond) durations and sub-ms rise-times and fall-times, however a small fraction of them had longer timescales associated with them. Most were single pulses, but about a dozen had double pulses and a few had more than two pulses. The TGFs are observed in a photon-by-photon recording mode, with each photon from eight independent detectors being tagged to the nearest two microseconds in four energy channels. The TGFs show very hard spectra, in most cases there are more photons recorded above 300 keV than below. Several of the TGFs were also recorded by the thicker (but smaller area) spectroscopy detectors that provided improved spectral resolution than the large area detectors. The temporal and spectral characteristics of the events and the capabilities of the detectors will be described in more detail than the in the original paper. The association of TGFs with thunderstorms is primarily statistical; the TGFs show a strong correlation with the global distribution of lightning, as observed with recent satellites. There has also been an association based upon coincidences with spheric events, however, this association is debatable due to the high spherics rate and the non-directionality of the detectors. This talk gives an update of the BATSE observations of TGFs were published by the BATSE instrument team over ten years ago.
Document ID
20050123894
Acquisition Source
Marshall Space Flight Center
Document Type
Conference Paper
Authors
Fishman, Jerry
(National Space Science and Technology Center Huntsville, AL, United States)
Date Acquired
August 22, 2013
Publication Date
January 1, 2005
Subject Category
Space Radiation
Meeting Information
Meeting: Union Radio-Scientifique Internationale National Meeting
Location: Boulder, CO
Country: United States
Start Date: January 5, 2005
End Date: January 8, 2005
Sponsors: International Scientific Radio Union
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.

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