The AGILE-MCAL instrument as TGF monitor
Abstract
The Mini-Calorimeter detector on-board the AGILE satellite was designed for astrophysical observations in the gamma-ray field, including cosmological Gamma-Ray-Burst (GRB). Thanks to its flexible on-board trigger logic for transient event, since the beginning of its operation, in April 2007, MCAL was also able to detect very fast transient phenomena in the energy range from 0.3 up to several MeV. These exhibit the characteristic of Terrestrial Gamma-ray Flashes (TGF). The candidate MCAL TGF events have a duration that can last from some hundred of μsec. to some millisec and reaches up to MeV in energy. For each triggered TGF its photon-by-photon history is recorded, with every photon described with energy, position on the detector plane and time (2 μsec. resolution) data. The on-ground data analysis strategy, based on more sophisticated algorithm than on-board logic, allows to discriminate between cosmological GRB and TGF and then to supply the spectral fluxes and the incoming area on the heart, within a 2000 km circle, of the observed TGF. MCAL can be then be used to increase the statistic of observed TGFs in the gamma ray domain and eventually to correlate them with observation in other energy ranges. The MCAL TGF observation strategy, as well as a short catalogue of detects events will be described and discussed.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2008
- Bibcode:
- 2008AGUFMAE21A..03L
- Keywords:
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- 3304 Atmospheric electricity;
- 3324 Lightning