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In astrophysics, gamma rays are conventionally defined as having photon energies above 100 keV and are the subject of gamma-ray astronomy, while radiation below 100 keV is classified as X-rays and is the subject of X-ray astronomy. Gamma rays are ionizing radiation and are thus hazardous to life.
Significant gamma-ray emission from our galaxy was first detected in 1967 [9] by the detector aboard the OSO 3 satellite. It detected 621 events attributable to cosmic gamma rays. However, the field of gamma-ray astronomy took great leaps forward with the SAS-2 (1972) and the Cos-B (1975–1982) satellites. These two satellites provided an ...
The Energetic Gamma Ray Experiment Telescope (EGRET) measured high energy (20 MeV to 30 GeV) gamma-ray source positions to a fraction of a degree and photon energy to within 15 percent. EGRET was developed by NASA Goddard Space Flight Center , the Max Planck Institute for Extraterrestrial Physics , and Stanford University .
A gamma ray burst (GRB) is the most powerful form of explosion in the known universe.They are produced when massive stars die, right before they turn into black holes, and were originally ...
Matter in a radiative zone is so dense that photons can travel only a short distance before they are absorbed or scattered by another particle, gradually shifting to longer wavelength as they do so. For this reason, it takes an average of 171,000 years for gamma rays from the core of the Sun to leave the radiative zone. Over this range, the ...
Neil Gehrels Swift Observatory, previously called the Swift Gamma-Ray Burst Explorer, is a NASA three-telescope space observatory for studying gamma-ray bursts (GRBs) and monitoring the afterglow in X-ray, and UV/visible light at the location of a burst. [5] It was launched on 20 November 2004, aboard a Delta II launch vehicle. [4]
The burst saturated the Fermi Gamma-ray Space Telescope's detector, [17] which captured gamma ray photons with energies exceeding 100 GeV. [18] GRB 221009A is by far the most productive event for very high-energy photons ever witnessed by scientific instrumentation.
Compton cameras are usually applied to detect gamma rays in the energy range where Compton scattering is the dominating interaction process, from a few hundred keV to several MeV. They are applied in fields such as astrophysics , nuclear medicine , and nuclear threat detection.