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06:28
Visualization of Low-Level Gamma Radiation Sources Using a Low-Cost, High-Sensitivity, Omnidirectional Compton Camera
Published on: January 30, 2020
Gamma-ray localization of terrestrial gamma-ray flashes.
M Marisaldi1, A Argan, A Trois
1INAF-IASF Bologna, Via Gobetti 101, I-40129 Bologna, Italy.
Physical Review Letters
|September 28, 2010
Summary
We precisely located terrestrial gamma-ray flashes (TGFs) using AGILE satellite data. These high-energy bursts originate in Earth's atmosphere and were pinpointed to terrestrial sites within 400 km.
Area of Science:
- Atmospheric Physics
- High-Energy Astrophysics
- Space Science
Background:
- Terrestrial gamma-ray flashes (TGFs) are brief, intense bursts of gamma rays and electrons produced in Earth's atmosphere.
- Previous studies lacked precise localization of TGFs, hindering understanding of their origin and mechanisms.
Purpose of the Study:
- To precisely localize TGFs using gamma-ray data from the AGILE satellite.
- To investigate the terrestrial origin of high-energy photons associated with TGFs.
Main Methods:
- Utilized AGILE satellite Silicon Tracker data correlated with TGFs detected by the AGILE Mini-Calorimeter.
- Developed an innovative event selection method for gamma-ray energies above 20 MeV.
- Localized TGFs using the AGILE gamma-ray imager with an angular accuracy of approximately 5-10° at 50 MeV.
Main Results:
- Detected 8 TGFs with gamma-ray photons above 20 MeV.
- All localized TGF-associated gamma rays indicated a terrestrial production site within 400 km of the subsatellite point.
- The AGILE satellite, at an altitude of 540 km, observed these gamma rays with minimal scattering or attenuation.
Conclusions:
- This study provides the first direct and precise spatial localization of TGFs from space.
- The findings confirm the terrestrial origin of TGFs and constrain their production region.
- The AGILE satellite's capabilities enable new insights into atmospheric high-energy phenomena.
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