Gamma rays are the most energetic part of the spectrum. They have the shortest wavelengths and highest frequencies. These characteristics make them extremely hazardous to life, but they also tell astronomers alo
Gamma-ray bursts (GRBs) are the brightest known sources of electromagnetic radiation with up to 1053erg emitted as gamma rays during an event which lasts just a few seconds. GRBs come from cosmological distances, with the measured and/or estimated redshift in the range0.5 ÷ 5. The ...
The hunt for PeVatrons as the origin of the most energetic photons observed in the Galaxy Article 22 April 2024 References Weekes, T. C. et al. Observation of TeV gamma rays from the Crab nebula using the atmospheric Cerenkov imaging technique. Astrophys. J. 342, 379–395 (1989). Arti...
Gamma-ray bursts. The short GRBs, on the other hand, are thought to originate from a completely different mechanism: the merger of two neutron stars. These events aren't nearly as powerful as their supernova cousins, but they wreak enough havoc locally to produce a flash of gamma-rays. ...
3. Canonical propagation of high-energy γ rays 3.1. Radiation transport of energetic photons in the Universe The propagation of energetic photons at energies considered here (109 eV to 1014 eV) is in most cases well approximated by the propagation in a classical vacuum. However, at cosmological...
Gamma-ray bursts (GRBs) are brief flashes of γ-rays and are considered to be the most energetic explosive phenomena in the Universe. The emission from GRBs comprises a short (typically tens of seconds) and bright prompt emission, followed by a much longer afterglow phase. During the ...
Gamma and E-beam radiations are the most energetic as they effectively kill vegetative pathogens and endospores. E-beam radiation delivers a higher radiation dose than Gamma radiation, penetrating less deep. Meanwhile, Gamma radiation can penetrate about 50 cm of the layers, E-beam radiation can...
"In the south pole, there is a surplus of emissions of higher energy, of photons with 20 to 150 gigaelectronvolts (GeV), while most of the less energetic photons come from the north pole," Arsioli added. The gamma-ray emissions from the poles were particularly concentrated in June 2014,...
Quasars, powered by gas accretion onto supermassive black holes1,2, rank among the most energetic objects in the Universe3,4. Although they are thought to be ignited by galaxy mergers5,6,7,8,9,10,11 and affect the surrounding gas12,13,14,15, observational constraints on both processes re...
1 Introduction Distant active galaxies, blazars, are among the strongest sources in the very-high-energy (VHE; above ∼ 100 GeV) gamma-ray band. They were detected even with the first mod- est instruments, despite the predicted [1,2] attenuation of the flux: energetic gamma rays from ...