scholarly journals Search for Emission of Ultra--High-Energy Radiation from Active Galactic Nuclei

1993 ◽  
Vol 418 ◽  
pp. 832 ◽  
Author(s):  
D. E. Alexandreas ◽  
G. E. Allen ◽  
D. Berley ◽  
S. Biller ◽  
R. L. Burman ◽  
...  
Keyword(s):  
Active Galactic Nuclei ◽  
Galactic Nuclei ◽  
High Energy ◽  
Ultra High Energy ◽  
High Energy Radiation ◽  
Energy Radiation

High-Energy Radiation From Active Galactic Nuclei

1994 ◽  
Vol 142 ◽  
pp. 923-928
Author(s):  
Marek Sikora
Keyword(s):  
Active Galactic Nuclei ◽  
Galactic Nuclei ◽  
Seyfert Galaxies ◽  
High Energy ◽  
Radiation Mechanisms ◽  
High Energy Radiation ◽  
Energy Radiation ◽  
X Ray ◽  
Radiation Properties ◽  
Galaxies Active

AbstractTwo recent findings concerning high-energy radiation properties of active galactic nuclei—discovery of breaks in hard X-ray spectra of Seyfert galaxies, and discovery of huge fluxes of hard gamma rays from blazars—seem to press us to change our standard views about radiation production in these objects. I review briefly the existing radiation models, confront them with the newest observations, and discuss newly emerging theoretical pictures which attempt to account for the discoveries.Subject headings: galaxies: active — galaxies: nuclei — radiation mechanisms: nonthermal

scholarly journals Planck Neutrinos as Ultra High Energy Cosmic Rays

2020 ◽  
Vol 29 (1) ◽  
pp. 40-46
Author(s):  
Dmitri L. Khokhlov
Keyword(s):  
Black Holes ◽  
Cosmic Rays ◽  
Standard Model ◽  
Active Galactic Nuclei ◽  
Planck Scale ◽  
Galactic Nuclei ◽  
High Energy ◽  
Ultra High Energy ◽  
High Energy Cosmic Rays ◽  
The Standard Model

AbstractThe studied conjecture is that ultra high energy cosmic rays (UHECRs) are hypothetical Planck neutrinos arising in the decay of the protons falling onto the gravastar. The proton is assumed to decay at the Planck scale into positron and four Planck neutrinos. The supermassive black holes inside active galactic nuclei, while interpreted as gravastars, are considered as UHECR sources. The scattering of the Planck neutrinos by the proton at the Planck scale is considered. The Planck neutrinos contribution to the CR events may explain the CR spectrum from 5 × 1018 eV to 1020 eV. The muon number in the Planck neutrinos-initiated shower is estimated to be larger by a factor of 3/2 in comparison with the standard model that is consistent with the observational data.

Daily search for emission of ultra-high-energy radiation from point sources

1993 ◽  
Vol 405 ◽  
pp. 353 ◽  
Author(s):  
D. E. Alexandreas ◽  
G. Allen ◽  
D. Berley ◽  
S. Biller ◽  
R. L. Burman ◽  
...  
Keyword(s):  
High Energy ◽  
Point Sources ◽  
Ultra High Energy ◽  
High Energy Radiation ◽  
Energy Radiation

scholarly journals DO ACTIVE GALACTIC NUCLEI CONVERT DARK MATTER INTO VISIBLE PARTICLES?

2008 ◽  
Vol 23 (16) ◽  
pp. 1151-1159 ◽  
Author(s):  
A. A. GRIB ◽  
YU. V. PAVLOV
Keyword(s):  
Black Hole ◽  
Dark Matter ◽  
Active Galactic Nuclei ◽  
Galactic Nuclei ◽  
High Energy ◽  
Grand Unification ◽  
Ultra High Energy ◽  
High Energy Cosmic Rays ◽  
Opposite Process ◽  
Penrose Process

The hypothesis that dark matter consists of superheavy particles with the mass close to the Grand Unification scale is investigated. These particles were created from vacuum by the gravitation of the expanding Universe and their decay led to the observable baryon charge. Some part of these particles with the lifetime larger than the time of breaking of the Grand Unification symmetry became metastable and survived up to the modern time as dark matter. However, in active galactic nuclei due to large energies of dark matter particles swallowed by the black hole and the possibility of the Penrose process for rotating black hole the opposite process can occur. Dark matter particles become interacting. Their decay on visible particles at the Grand Unification energies leads to the flow of ultra high energy cosmic rays observed by the Auger group. Numerical estimates of the effect leading to the observable numbers are given.

scholarly journals Ultra-high energy radiation from young supernovae

Nature ◽  
1988 ◽  
Vol 332 (6162) ◽  
pp. 314-314 ◽  
Author(s):  
T. K. GAISSER ◽  
T. STANEV ◽  
F. HALZEN
Keyword(s):  
High Energy ◽  
Ultra High Energy ◽  
High Energy Radiation ◽  
Energy Radiation
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