scholarly journals HIGH ENERGY COSMIC RAYS, GAMMA RAYS AND NEUTRINOS FROM AGN

2008 ◽  
Vol 23 (24) ◽  
pp. 1991-1997 ◽  
Author(s):  
YUKIO TOMOZAWA
Keyword(s):  
Energy Spectrum ◽  
Cosmic Rays ◽  
Active Galactic Nuclei ◽  
Gamma Rays ◽  
Heavy Particle ◽  
Galactic Nuclei ◽  
Cosmic Ray ◽  
High Energy ◽  
Neutrino Detectors ◽  
High Energy Cosmic Rays

The author reviews a model for the emission of high energy cosmic rays, gamma-rays and neutrinos from AGN (Active Galactic Nuclei) that he has proposed since 1985. Further discussion of the knee energy phenomenon of the cosmic ray energy spectrum requires the existence of a heavy particle with mass in the knee energy range. A possible method of detecting such a particle in the Pierre Auger Project is suggested. Also presented is a relation between the spectra of neutrinos and gamma-rays emitted from AGN. This relation can be tested by high energy neutrino detectors such as ICECUBE, the Mediterranean Sea Detector and possibly by the Pierre Auger Project.

scholarly journals The Origins of High-Energy Cosmic Rays

1994 ◽  
Vol 142 ◽  
pp. 937-944
Author(s):  
W. I. Axford
Keyword(s):  
Energy Spectrum ◽  
Cosmic Rays ◽  
Active Galactic Nuclei ◽  
Supernova Remnants ◽  
Galactic Nuclei ◽  
High Energy ◽  
Shock Acceleration ◽  
Acceleration Of Particles ◽  
Intermediate Region ◽  
High Energy Cosmic Rays

AbstractOur current understanding of acceleration processes for Galactic and extragalactic cosmic rays is briefly reviewed. Shock acceleration in supernova remnants remains the most favored process for cosmic rays up to the “knee” of the all-particle total energy spectrum at 1014 - 1015 eV. The highest energy particles are almost certainly extragalactic, and the most favored sources are associated with active galactic nuclei in one way or another. The intermediate region between rigidities of 1014 and 1018 V is more difficult to understand, although a galactic origin is preferred at present. The problem of making a smooth join in the spectrum at the knee suggests that these particles should not be considered to be independent of those at lower energies.Subject headings: acceleration of particles — cosmic rays — shock waves

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.

scholarly journals Prospects of testing an UHECR single source class model with the K-EUSO orbital telescope

2019 ◽  
Vol 210 ◽  
pp. 06011
Author(s):  
Oleg Kalashev ◽  
Maxim Pshirkov ◽  
Mikhail Zotov
Keyword(s):  
Cosmic Rays ◽  
Active Galactic Nuclei ◽  
Large Scale ◽  
Space Station ◽  
Galactic Nuclei ◽  
High Energy ◽  
Single Source ◽  
Class Model ◽  
High Energy Cosmic Rays ◽  
Celestial Sphere

KLYPVE-EUSO (K-EUSO) is a planned orbital detector of ultra-high energy cosmic rays (UHECRs), which is to be deployed on board the International Space Station. K-EUSO is expected to have a uniform exposure over the celestial sphere and register from 120 to 500 UHECRs at energies above 57 EeV in a 2-year mission. We employed the TransportCR and CRPropa 3 packages to estimate prospects of testing a minimal single source class model for extragalactic cosmic rays and neutrinos by Kachelrieß, Kalashev, Ostapchenko and Semikoz (2017) with K-EUSO in terms of the large-scale anisotropy. Nearby active galactic nuclei Centaurus A, M82, NGC 253, M87 and Fornax A were considered as possible sources of UHECRs. We demonstrate that an observation of more than 200 events will allow testing predictions of the model with a high confidence level providing the fraction of events arriving from any of the sources is ^10-15%, with a smaller contribution for larger samples. These numbers agree with theoretical expectations of a possible contribution of a single source in the UHECR flux. Thus, K-EUSO can provide good opportunities for verifying the minimal model basing on an analysis of the large-scale anisotropy of arrival directions of UHECRs.

scholarly journals Soft gamma rays from low accreting supermassive black holes and connection to energetic neutrinos

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Shigeo S. Kimura ◽  
Kohta Murase ◽  
Péter Mészáros
Keyword(s):  
Active Galactic Nuclei ◽  
Gamma Rays ◽  
Gamma Ray ◽  
Galactic Nuclei ◽  
High Energy ◽  
Hadronic Interactions ◽  
Neutrino Detectors ◽  
Accretion Flows ◽  
Diffuse Background ◽  
The Universe

AbstractThe Universe is filled with a diffuse background of MeV gamma-rays and PeV neutrinos, whose origins are unknown. Here, we propose a scenario that can account for both backgrounds simultaneously. Low-luminosity active galactic nuclei have hot accretion flows where thermal electrons naturally emit soft gamma rays via Comptonization of their synchrotron photons. Protons there can be accelerated via turbulence or reconnection, producing high-energy neutrinos via hadronic interactions. We demonstrate that our model can reproduce the gamma-ray and neutrino data. Combined with a contribution by hot coronae in luminous active galactic nuclei, these accretion flows can explain the keV – MeV photon and TeV – PeV neutrino backgrounds. This scenario can account for the MeV background without non-thermal electrons, suggesting a higher transition energy from the thermal to nonthermal Universe than expected. Our model is consistent with X-ray data of nearby objects, and testable by future MeV gamma-ray and high-energy neutrino detectors.

scholarly journals ULTRA HIGH ENERGY COSMIC RAYS: ORIGIN AND PROPAGATION

2010 ◽  
Vol 25 (18) ◽  
pp. 1467-1481 ◽  
Author(s):  
TODOR STANEV
Keyword(s):  
Cosmic Rays ◽  
Gamma Rays ◽  
Cosmic Ray ◽  
High Energy ◽  
Ultra High Energy ◽  
Ultrahigh Energy ◽  
High Energy Cosmic Rays ◽  
Astrophysical Objects ◽  
Ultrahigh Energy Cosmic Rays ◽  
The Universe

We introduce the highest energy cosmic rays and briefly review the powerful astrophysical objects where they could be accelerated. We then introduce the interactions of different cosmic ray particles with the photon fields of the Universe and the formation of the cosmic ray spectra observed at Earth. The last topic is the production of secondary gamma rays and neutrinos in the interactions of the ultrahigh energy cosmic rays.

scholarly journals ON ACCELERATION AND PROPAGATION OF ULTRA-HIGH ENERGY COSMIC RAYS

2009 ◽  
Vol 18 (10) ◽  
pp. 1583-1586
Author(s):  
MARTIN LEMOINE
Keyword(s):  
Cosmic Rays ◽  
Active Galactic Nuclei ◽  
Large Scale ◽  
Gamma Ray ◽  
Galactic Nuclei ◽  
High Energy ◽  
Current Data ◽  
Type I ◽  
Ultra High Energy ◽  
High Energy Cosmic Rays

This paper discusses the correlation reported in 2008 by the Pierre Auger Observatory (PAO) of the arrival directions of the highest energy cosmic rays with active galactic nuclei (AGN). It is argued that these correlating AGN do not have the power required to be the sources of ultra-high energy protons. This current PAO dataset is further shown to disfavor giant radio-galaxies (both Fanaroff–Riley type I and II) as sources of ultra-high energy protons. The current data thus likely point to the local large scale structure, in which the actual sources of ultra-high energy cosmic rays camouflage. Finally, it is shown that the last gamma-ray burst in Centaurus A could explain, through rescattering on the Cen A lobes, the apparent cluster of events in this direction.

scholarly journals ACTIVE GALACTIC NUCLEI: SOURCES FOR ULTRA HIGH ENERGY COSMIC RAYS

2009 ◽  
Vol 18 (10) ◽  
pp. 1577-1581 ◽  
Author(s):  
P. L. BIERMANN ◽  
J. K. BECKER ◽  
L. CARAMETE ◽  
L. GERGELY ◽  
I. C. MARIŞ ◽  
...  
Keyword(s):  
Cosmic Rays ◽  
Radio Galaxy ◽  
Galactic Nuclei ◽  
Cosmic Ray ◽  
High Energy ◽  
Galactic Cosmic Rays ◽  
Ultra High Energy ◽  
Heavy Nuclei ◽  
High Energy Cosmic Rays ◽  
Relativistic Jet

Ultra high energy cosmic ray events presently show a spectrum, which we interpret here as galactic cosmic rays due to a starburst, in the radio galaxy Cen A which is pushed up in energy by the shock of a relativistic jet. The knee feature and the particles with energy immediately higher in galactic cosmic rays then turn into the bulk of ultra high energy cosmic rays. This entails that all ultra high energy cosmic rays are heavy nuclei. This picture is viable if the majority of the observed ultra high energy events come from the radio galaxy Cen A, and are scattered by intergalactic magnetic fields across much of the sky.

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