M. Marisaldi, F. Fuschino, C. Labanti, A. Bulgarelli, F. Gianotti, M. Trifoglio, M. Tavani, A. Argan, E. Del Monte, F. Longo, G. Barbiellini, A. Giuliani, A. Trois, for the AGILE collaboration
The AGILE satellite, operating since mid 2007 and primarily devoted to
high-energy astrophysics, is one of the only three currently operating space
instruments capable of detecting Terrestrial Gamma-Ray Flashes (TGFs), together
with RHESSI and $Fermi$-GBM. Thanks to the AGILE Mini-Calorimeter instrument
energy range extended up to 100MeV and its flexible trigger logic on
sub-millisecond time scales, AGILE is detecting more than 10 TGFs/month, adding
a wealth of observations which pose severe constrains on production models. The
main AGILE discoveries in TGF science during two and a half years of
observations are the following: 1) the TGF spectrum extends well above 40 MeV,
2) the high energy tail of the TGF spectrum is harder than expected and cannot
be easily explained by previous theoretical models, 3) TGFs can be localized
from space using high-energy photons detected by the AGILE gamma-ray imaging
detector. In this presentation we will describe the characteristics of the
2.5-years AGILE TGF sample, focusing on the recent results concerning the TGF
high-energy spectral characteristics.
View original:
http://arxiv.org/abs/1111.2188
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