Search for Very Short Bursts with the AGILE Mini-Calorimeter

• Main Authors: Marisaldi, M., Labanti, C., Fuschino, F., Trifoglio, M., Galli, M., Argan, A., Barbiellini, G., Longo, F., Moretti, E., Boffelli, F., Cattaneo, P. W., Rappoldi, A., Bulgarelli, A., Di Cocco, G., Gianotti, F., Caraveo, P., Chen, A., Fornari, F., Giuliani, A., Mereghetti, S.
• Format: Conference Proceeding
• Language: English
• Subjects: ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; COSMIC GAMMA BURSTS; COSMIC GAMMA SOURCES; COSMIC PHOTONS; GAMMA ASTRONOMY; GAMMA DETECTION; GENERAL AND MISCELLANEOUS//MATHEMATICS, COMPUTING, AND INFORMATION SCIENCE; ORBITS; SCINTILLATION COUNTERS; SCINTILLATIONS; SHOWER COUNTERS; TELEMETRY
• ISSN: 0094-243X; 1551-7616
• DOI: 10.1063/1.3155937

In this paper the results of the first months of burst search on very short time scales with the Mini-Calorimeter (MCAL) on-board the AGILE mission are presented. MCAL is equipped with a flexible on-board trigger logic for autonomous GRB detection. In addition to standard trigger time windows, MCAL has been equipped with trigger capabilities on 16 ms, 1 ms and sub-millisecond time windows. Since June 2008 burst search on these short time scales has been enabled, resulting in an average rate of 4 triggers/orbit, compliant with telemetry budget. An on-ground rejection strategy is applied, allowing more sophisticated selection criteria than those allowed by the on-board trigger logic. Triggers due to instrumental effects or geophysical phenomena can be spotted due to their photon-by-photon pattern; what remains after this cleaning is an almost unexplored territory and could shed light on the origin of very short bursts. The trigger criteria, as well as the on-ground rejection strategy and the properties of the selected events will be described and discussed.