Details

Autor(en) / Beteiligte

• Tierney, D.
• Briggs, M. S.
• Fitzpatrick, G.
• Chaplin, V. L.
• Foley, S.
• McBreen, S.
• Connaughton, V.
• Xiong, S.
• Byrne, D.
• Carr, M.
• Bhat, P. N.
• Fishman, G. J.
• Greiner, J.
• Kippen, R. M.
• Meegan, C. A.
• Paciesas, W. S.
• Preece, R. D.
• von Kienlin, A.
• Wilson-Hodge, C.

Titel

Fluence distribution of terrestrial gamma ray flashes observed by the Fermi Gamma-ray Burst Monitor

Ist Teil von

• Journal of geophysical research. Space physics, 2013-10, Vol.118 (10), p.6644-6650

Ort / Verlag

Hoboken, NJ: Blackwell Publishing Ltd

Erscheinungsjahr

2013

Quelle

Wiley Online Library

Beschreibungen/Notizen

• The observed γray fluence distribution of terrestrial gamma ray flashes (TGFs) detected by the Fermi Gamma‐ray Burst Monitor (GBM) is altered by instrumental effects. We perform corrections for dead time, pulse pileup, and detection efficiency in a model‐independent manner. A sample of 106 GBM TGFs is selected to include both TGFs that triggered GBM and weaker TGFs found using an off‐line search. Detector dead time and pulse pileup lower the observed fluence of each TGF and the detection efficiency causes weaker TGFs to have a lower probability of detection than brighter TGFs. Monte Carlo simulations are performed in each case to correct for these effects. The corrected fluence distribution is well fit with a power law of index α=−2.20±0.13. This is consistent with previous estimates using other techniques. Neither a high‐fluence cutoff nor a low‐fluence limit is found. The fluence distribution is also expressed in units of TGF h−1 km−2 versus photons cm−2 per TGF. Key Points Determine and correct for GBM instrumental effects on TGFs To determine the true TGF photon fluence distribution at Fermi altitude To estimate the number of TGFs per year under the orbit of Fermi