| タイトル | The Latest Space-Borne Observations of TGFs from Fermi-GBM |
| 本文（外部サイト） | http://hdl.handle.net/2060/20100040619 |
| 著者（英） | Fishman, Gerald J. |
| 著者所属（英） | NASA Marshall Space Flight Center |
| 発行日 | 2010-10-25 |
| 言語 | eng |
| 内容記述 | The Gamma-ray Burst Monitor (GBM) on the Fermi Gamma-ray Space Telescope Observatory (Fermi) is detecting about two TGFs per week. This rate has increased by a factor of approx.eight since launch when flight software was uploaded to the spacecraft in November 2009 in order to increase the sensitivity of GBM to TGFs. Weaker, un-triggered TGFs are now also being observed about once per day over selected low-latitude regions Americas. The high efficiency and time resolution (2 s) of GBM allows temporal features to be resolved so that some insight may be gained on the origin and transport of the gamma-ray photons through the atmosphere. TGFs are observed to be shorter than previously thought, with an average duration of approx.100 micro-s. The absolute times of TGFs are known to approx.10 micro-s, allowing accurate correlations of TGFs with lightning networks and other lightning-related phenomena. The events are observed in the thick bismuth germanate (BGO) scintillation detectors of GBM with photon energies above 40 MeV. Other new results on the temporal and spectral characteristics of TGFs will be presented, along with properties of several electron-positron TGF events that have been identified. |
| NASA分類 | Astronomy |
| レポートNO | M10-1059 |
| 権利 | No Copyright |
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