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Related papers: Fermi Pulsars and the Cosmic Ray Knee

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The pointing directions of extensive air showers observed at the Pierre Auger Observatory were fitted within 3.1 degree with positions of the nearby active galactic nuclei from the Veron-Cetty and P. Veron catalog. The cosmic ray luminosity…

Astrophysics · Physics 2008-04-30 L. G. Dedenko , D. A. Podgrudkov , T. M. Roganova , G. F. Fedorova

Galactic cosmic ray (CR) acceleration to the knee in the spectrum at a few PeV is only possible if the magnetic field ahead of a supernova remnant (SNR) shock is strongly amplified by CR escaping the SNR. A model formulated in terms of the…

High Energy Astrophysical Phenomena · Physics 2015-06-12 AR Bell , KM Schure , B Reville , G Giacinti

In the last few years several experiments have shown that the cosmic ray spectrum below the knee is not a perfect power-law. In particular, the proton and helium spectra show a spectral hardening by ~ 0.1-0.2 in spectral index at particle…

High Energy Astrophysical Phenomena · Physics 2017-12-27 S. Recchia , S. Gabici

In the cosmic ray spectrum, there are two knees (abrupt changes of slopes) located around the energies $E_{th}=10^{15.5}$ eV and $10^{17.8}$ eV respectively. Based on the pioneering work by Kostelecky and Ehrlich, we ascribe the first knee…

High Energy Physics - Phenomenology · Physics 2007-05-23 Guang-Jiong Ni

The Fermi acceleration model was introduced to describe how cosmic ray particles are accelerated to great speeds by interacting with moving magnetic fields. We identify a new variation of the model where light ions interact with a moving…

Plasma Physics · Physics 2022-02-02 J. C. Waybright , M. E. Mlodik , N. J. Fisch

An analysis is made of the fine structure in the cosmic ray energy spectrum: new facets of present observations and their interpretation and the next step. It is argued that less than about 10% of the intensity of the helium `peak' at the…

High Energy Astrophysical Phenomena · Physics 2011-11-15 A. D. Erlykin , A. W. Wolfendale

The analysis of cosmic rays fluxes as a function of energy reveals a {\it knee} slightly below $10^{16}$ eV and an {\it ankle} close to $10^{19}$ eV. Their physical origins remain up to now quite enigmatic; in particular, no elementary…

Astrophysics · Physics 2007-05-23 Constantino Tsallis , Joao C. Anjos , Ernesto P. Borges

Recent progress in cosmic ray physics covering the energy range from about 10^{14} eV to 10^{19} eV is reviewed. The most prominent features of the energy spectrum are the so called `knee' at E ~ 3 * 10^{15} eV and the `ankle' at few…

Astrophysics · Physics 2008-11-26 Karl-Heinz Kampert

Based on the generic acceleration model, which suggests different types of electromagnetic interactions between the cosmic charged particles and the different configurations of the electromagnetic (plasma) fields, the ultra high energy…

High Energy Astrophysical Phenomena · Physics 2014-03-21 A. Tawfik , A. Saleh , M. T. Ghoneim , A. Hady

Young supernova remnants are thought to be the sites where cosmic ray acceleration occurs by the mechanism of diffusive shock acceleration. The maximum energy gained in this process is conventionally extimated to have a value close to, but…

Astrophysics · Physics 2007-05-23 L. O'C. Drury , E. van der Swaluw , O. Carroll

In Aristotelian Electrodynamics (AE), due to radiation over-damping, the velocity rather than the acceleration of a charge is determined by the local electromagnetic field. Treating electrons and positrons separately, AE seems to give a…

High Energy Astrophysical Phenomena · Physics 2013-03-19 Andrei Gruzinov

The origin of the knee in the energy spectrum of cosmic rays is an outstanding problem in astroparticle physics. Numerous mechanisms have been proposed to explain the structure in the all-particle spectrum. In the article basic ideas of…

Astrophysics · Physics 2015-06-24 Joerg R. Hoerandel

First-order Fermi acceleration processes at ultrarelativistic shocks are studied with Monte Carlo simulations. The accelerated particle spectra are derived by integrating the exact particle trajectories in a turbulent magnetic field near…

Astrophysics · Physics 2009-11-13 Jacek Niemiec , Michal Ostrowski

Astrophysical sources of nuclei are expected to produce a broad spectrum of isotopes, many of which are unstable. An unstable nucleus can beta-decay outside the source into a single-electron ion. Heavy one-electron ions, thus formed, can be…

High Energy Astrophysical Phenomena · Physics 2012-01-05 Alexander Kusenko , M. B. Voloshin

It is proven that a polarized neutron gets accelerated by internal nuclear forces along the coherent rotation of its spin. The net force upon the neutron arises from the weak nuclear interactions between its quarks. It is the result of the…

High Energy Physics - Phenomenology · Physics 2025-04-22 M. Donaire

Cross sections are calculated for neutrino scattering off heavy nuclei at energies below 50 MeV. The theory of Fermi liquid is applied to estimate the rate of neutrino-nucleon elastic and inelastic scattering in a nuclear medium in terms of…

Nuclear Theory · Physics 2008-11-26 Gennady I. Lykasov , Vadim A. Bednyakov

The acceleration of ultrahigh energy nuclei in fast spinning newborn pulsars can explain the observed spectrum of ultrahigh energy cosmic rays and the trend towards heavier nuclei for energies above $10^{19}\,$eV as reported by the Auger…

High Energy Astrophysical Phenomena · Physics 2015-06-15 Ke Fang , Kumiko Kotera , Angela V. Olinto

The applicability of first-order Fermi acceleration in explaining the cosmic ray spectrum has been reexamined using recent results on shock acceleration mechanisms from the Multiscale Magnetospheric mission in Earth's bow shock. It is…

High Energy Astrophysical Phenomena · Physics 2026-02-17 Krzysztof Stasiewicz

We here argue that the "knee" of the cosmic ray energy distribution at $E_c \sim 1$ PeV represents a second order phase transition of cosmic proportions. The discontinuity of the heat capacity per cosmic ray particle is given by $\Delta…

High Energy Physics - Phenomenology · Physics 2015-02-10 A. Widom , J. Swain , Y. Srivastava

Laboratory experiments to explore plasma conditions and stimulated particle acceleration can illuminate aspects of the cosmic particle acceleration process. Here we discuss the cosmic-ray candidate source object variety, and what has been…

High Energy Astrophysical Phenomena · Physics 2009-12-15 Roland Diehl