Browsing Bergen Open Research Archive by Author "Gjesteland, Thomas"
Now showing items 1-12 of 12
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An altitude and distance correction to the initial fluence distribution of TGFs
Nisi, Ragnhild Schrøder; Østgaard, Nikolai; Gjesteland, Thomas; Collier, Andrew B. (Peer reviewed; Journal article, 2014-10)The source fluence distribution of terrestrial gamma ray flashes (TGFs) has been extensively discussed in recent years, but few have considered how the TGF fluence distribution at the source, as estimated from satellite ... -
Confining the angular distribution of terrestrial gamma ray flash emission
Gjesteland, Thomas; Østgaard, Nikolai; Collier, A. B.; Carlson, B. E.; Cohen, M. B.; Lehtinen, N. G. (Peer reviewed; Journal article, 2011-11-11) -
Effects of dead time losses on terrestrial gamma ray flash measurements with the Burst and Transient Source Experiment
Gjesteland, Thomas; Østgaard, Nikolai; Connell, P. H.; Stadsnes, J.; Fishman, G. J. (Peer reviewed; Journal article, 2010-05-05) -
Enhanced detection of terrestrial gamma-ray flashes by AGILE
Marisaldi, Martino; Argan, A; Ursi, Alessandro; Gjesteland, Thomas; Fuschino, F; Labanti, C; Galli, M; Tavani, M; Pittori, C; Verrecchia, F; D´Amico, F.; Østgaard, Nikolai; Mereghetti, S; Campana, R; Cattaneo, PW; Bulgarelli, S; Colafrancesco, S; Dietrich, S; Longo, F; Gianotti, F.; Giommi, P; Rappoldi, A; Trifoglio, M; Trois, A (Peer reviewed; Journal article, 2015-11-06)At the end of March 2015 the onboard software configuration of the Astrorivelatore Gamma a Immagini Leggero (AGILE) satellite was modified in order to disable the veto signal of the anticoincidence shield for the minicalorimeter ... -
Modeling the relativistic runaway electron avalanche and the feedback mechanism with GEANT4
Skeltved, Alexander Broberg; Østgaard, Nikolai; Gjesteland, Thomas; Celestin, Sebastien; Carlson, Brant Edward (Peer reviewed; Journal article, 2014-11)This paper presents the first study that uses the GEometry ANd Tracking 4 (GEANT4) toolkit to do quantitative comparisons with other modeling results related to the production of terrestrial gamma ray flashes and high-energy ... -
A new method reveals more TGFs in the RHESSI data
Gjesteland, Thomas; Østgaard, Nikolai; Collier, A. B.; Carlson, B. E.; Eyles, C.; Smith, D. M. (Peer reviewed; Journal article, 2012-03-07) -
A new population of terrestrial gamma-ray flashes in the RHESSI data
Østgaard, Nikolai; Albrechtsen, Kjetil; Gjesteland, Thomas; Collier, Andrew B. (Peer reviewed; Journal article, 2015-12-23)Terrestrial gamma-ray flashes (TGFs) are the most energetic photon phenomenon occurring naturally on Earth. An outstanding question is as follows: Are these flashes just a rare exotic phenomenon or are they an intrinsic ... -
Observation of intrinsically bright terrestrial gamma ray flashes from the Mediterranean basin
Gjesteland, Thomas; Østgaard, Nikolai; Laviola, Sante; Miglietta, M M; Arnone, Enrico; Marisaldi, Martino; Fuschino, F; Collier, Andrew B.; Fabro, F; Montanya, J (Peer reviewed; Journal article, 2015-12-14)We present three terrestrial gamma ray flashes (TGFs) observed over the Mediterranean basin by the Reuven Ramaty High Energy Solar Spectroscope Imager (RHESSI) satellite. Since the occurrence of these events in the ... -
On the timing between terrestrial gamma ray flashes, radio atmospherics, and optical lightning emission
Gjesteland, Thomas; Østgaard, Nikolai; Bitzer, Phillip; Christian, Hugh J. (Peer reviewed; Journal article, 2017)On 25 October 2012 the Reuven Ramaty High Energy Solar Spectroscope Imager (RHESSI) and the Tropical Rainfall Measuring Mission (TRMM) satellites passed over a thunderstorm on the coast of Sri Lanka. RHESSI observed a ... -
Production altitude and time delays of the terrestrial gamma flashes: Revisiting the Burst and Transient Source Experiment spectra
Østgaard, Nikolai; Gjesteland, Thomas; Stadsnes, J.; Connell, P. H.; Carlson, B. E. (Peer reviewed; Journal article, 2008-02-19) -
Properties of Terrestrial Gamma ray Flashes. Modelling and Analysis of BATSE and RHESSI data
Gjesteland, Thomas (Doctoral thesis, 2012-06-15)This thesis objective is to study Terrestrial Gamma ray Flashes (TGFs), which are short burst (∼ 1 ms) of gamma-radiation from thunderstorms first discovered by Fishman et al. [1994]. The measured photons energies in TGFs ... -
The true fluence distribution of terrestrial gamma flashes at satellite altitude
Østgaard, Nikolai; Gjesteland, Thomas; Hansen, R. S.; Collier, A. B.; Carlson, B. E. (Peer reviewed; Journal article, 2012-03-24)