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Multichannel Cosmic Ray (CR) spectra and the large scale CR anisotropy can hardly be made compatible in the framework of conventional isotropic and homogeneous propagation models. These models also have problems explaining the longitude…

High Energy Astrophysical Phenomena · Physics 2012-06-13 Carmelo Evoli , Daniele Gaggero , Dario Grasso , Luca Maccione

An overview on the present observational status and phenomenological understanding of cosmic rays above 10^16 eV is given. Above these energies the cosmic ray flux is expected to be gradually dominated by an extra-galactic component. In…

Astrophysics · Physics 2008-12-16 Michael Unger

Recently, gas entropy at the outskirts of galaxy clusters attracts much attention. We propose that the entropy profiles could be used to study cosmic-ray (CR) acceleration around the clusters. If the CRs are effectively accelerated at the…

High Energy Astrophysical Phenomena · Physics 2015-06-15 Yutaka Fujita , Yutaka Ohira , Ryo Yamazaki

A brief motivation for studying cosmic rays at energies 10^14 < E < 10^17 eV is given. Besides astrophysical interests in identifying and understanding their sources, there are also particle physics aspects related to their transport…

Astrophysics · Physics 2007-05-23 K. -H. Kampert , KASCADE Collaboration

We investigate the escape process from a perpendicular shock region of a spherical shock in the interstellar medium (ISM). The diffusive shock acceleration in the perpendicular shock of supernova remnants (SNRs) has been expected to…

High Energy Astrophysical Phenomena · Physics 2021-11-03 Shoma F. Kamijima , Yutaka Ohira

Context. Indirect observations of the cosmic-ray electron (CRE) distribution via synchrotron emission is crucial for deepening the understanding of the CRE transport in the interstellar medium, and in investigating the role of galactic…

High Energy Astrophysical Phenomena · Physics 2023-01-24 Julien Dörner , Patick Reichherzer , Julia Becker Tjus , Volker Heesen

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

Galactic cosmic rays (CRs) are accelerated by astrophysical shocks, primarily supernova remnants (SNRs), via diffusive shock acceleration (DSA), an efficient mechanism that predicts power-law energy distributions of CRs. However,…

High Energy Astrophysical Phenomena · Physics 2021-09-24 Rebecca Diesing , Damiano Caprioli

The composition of the overall spectrum of cosmic rays (CRs) is studied under the assumption that ultra high energy CRs above the energy 10^{17} eV are produced at the shock created by the expanding cocoons around active galactic nuclei…

High Energy Astrophysical Phenomena · Physics 2011-02-11 E. G. Berezhko

We discuss the differences induced by the assumed composition of extragalactic sources on the predicted UHECR spectrum and the energy evolution of $<X_{\max}>$, i.e. the mean value of the atmospheric depth at the cosmic-ray air shower…

Astrophysics · Physics 2009-11-13 D. Allard , A. V. Olinto , E. Parizot

Recent precise measurements of cosmic ray (CR) spectra show that the energy distribution of protons is softer than those of heavier nuclei, and there are spectral hardenings for all nuclear compositions above $\sim$200 GV. Models proposed…

High Energy Astrophysical Phenomena · Physics 2017-08-02 Yiran Zhang , Siming Liu , Qiang Yuan

We develop a theory to account for the cosmic ray spectrum between 1 GeV and 10^4 GeV following the earlier papers of this series. We use the basic concept that the cosmic ray particles are accelerated in a supernova shock that travels…

Astrophysics · Physics 2007-05-23 Peter L. Biermann , Richard G. Strom

Some new developments obtained in the last few years concerning the propagation of high energy cosmic rays are discussed. In particular, it is shown how the inclusion of drift effects in the transport diffusion equations leads naturally to…

Astrophysics · Physics 2011-04-11 Esteban Roulet

With experimental results of AMS on the spectra of cosmic ray (CR) $e^{-}$, $e^{+}$, $e^{-}+e^{+}$ and positron fraction, as well as new measurements of CR $e^{-}+e^{+}$ flux by HESS, one can better understand the CR lepton ($e^{-}$ and…

High Energy Astrophysical Phenomena · Physics 2019-03-29 Shi Zhao-Dong , Liu Siming

We argue that the diffusion of cosmic rays in the Galactic magnetic field has to be strongly anisotropic. As a result, the number of CR sources contributing to the local CR flux is reduced by a factor $\sim 200$. The CR density is therefore…

High Energy Astrophysical Phenomena · Physics 2019-05-22 M. Kachelriess

We introduce a static toy model of the cosmic ray (CR) universe in which cosmic ray propagation is taken to be diffusive and cosmic ray sources are distributed randomly with a density the same as that of local L* galaxies, $5 \times…

Astrophysics · Physics 2007-10-29 Roger Clay , Roland M. Crocker

At present, there is no consensus on whether the spectral break in the cosmic-ray flux of all elements around 4 PeV is a general characteristic of the Milky Way or is determined by a combination of factors that significantly affect the…

High Energy Astrophysical Phenomena · Physics 2025-07-11 Vladislav Borisov , Vladimir Yurovsky , Alexandra Peryatinskaya , Ilya Kudryashov

Energy spectra of galactic cosmic rays calculated within the framework of the NoRD (nonlocal relativistic diffusion) model are presented. The model accounts for the turbulent character of the interstellar medium and the relativistic speed…

High Energy Astrophysical Phenomena · Physics 2017-03-21 Vladimir Uchaikin , Renat Sibatov

Cosmic rays (CRs) are transported out of the galaxy by diffusion and advection due to streaming along magnetic field lines and resonant scattering off self-excited Magneto-Hydro-Dynamic (MHD) waves. Thus momentum is transferred to the…

Astrophysics of Galaxies · Physics 2019-10-02 E. A. Dorfi , D. Steiner , F. Ragossnig , D. Breitschwerdt

We investigate the transport of spectrally resolved cosmic ray (CR) protons with kinetic energies between $1-100$ GeV within the dynamic, multiphase interstellar medium (ISM), using a two-moment CR fluid solver applied to a TIGRESS MHD…

High Energy Astrophysical Phenomena · Physics 2025-07-02 Lucia Armillotta , Eve C. Ostriker , Nora B. Linzer