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Related papers: Probing Nearby CR Accelerators and ISM Turbulence …

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In the standard diffusive picture for transport of cosmic rays (CRs), a gradient in the CR density induces a typically small, dipolar anisotropy in their arrival directions. This has been widely advertised as a tool for finding nearby…

High Energy Astrophysical Phenomena · Physics 2015-01-15 Philipp Mertsch , Stefan Funk

We investigate the diffusion of cosmic rays (CR) close to their sources. Propagating individual CRs in purely isotropic turbulent magnetic fields with maximal scale of spatial variations Lmax, we find that CRs diffuse anisotropically at…

High Energy Astrophysical Phenomena · Physics 2012-06-29 G. Giacinti , M. Kachelriess , D. V. Semikoz

In our previous work, we have investigated Galactic cosmic ray (GCR) spectra and anisotropy from 100 GeV to PeV, under anisotropic propagation model with axisymmetric distributed galactic sources. Numerous observational evidence have…

High Energy Astrophysical Phenomena · Physics 2024-12-24 Aifeng Li , Zhaodong Lv , Wei Liu , Yiqing Guo , Fangheng Zhang

The distribution of arrival directions of cosmic rays is remarkably isotropic, which is a consequence of their repeated scattering in magnetic fields. Yet, high-statistics observatories like IceCube and HAWC have revealed the presence of…

High Energy Astrophysical Phenomena · Physics 2019-12-04 Philipp Mertsch , Markus Ahlers

Within the classical convection--diffusion approximation, we show that the angular distribution of cosmic rays (CRs) in a highly turbulent flow may exhibit significant small-scale anisotropies. The CR intensity angular power spectrum $…

High Energy Astrophysical Phenomena · Physics 2024-02-27 Yiran Zhang , Siming Liu

The origin of the bulk of cosmic rays (CRs) observed at Earth is the topic of a century long investigation, paved with successes and failures. From the energetic point of view, supernova remnants (SNRs) remain the most plausible sources of…

High Energy Astrophysical Phenomena · Physics 2016-12-09 Pasquale Blasi

We consider a possibility of identification of sources of cosmic rays (CR) of the energy above 1 TeV via observation of degree-scale extended gamma-ray emission which traces the locations of recent sources in the Galaxy. Such emission in…

High Energy Astrophysical Phenomena · Physics 2013-05-30 A. Neronov , D. V. Semikoz

We show that the well-known discrepancy between the radial dependence of the Galactic cosmic ray (CR) nucleon distribution, as inferred most recently from EGRET observations of diffuse gamma-rays above 100 MeV, and of the most likely CR…

Astrophysics · Physics 2009-11-07 D. Breitschwerdt , V. A. Dogiel , H. J. Voelk

The gamma-ray & neutrino visibility of cosmic ray (CR) accelerators will be dramatically increased by the presence of molecular material abutting such sites due to the increased probability of pion production -- and, in the case of neutral…

A correct description of cosmic-ray (CR) diffusion in turbulent plasma is essential for many astrophysical and heliospheric problems. This paper aims to present physical diffusion behavior of CRs in actual turbulent magnetic fields, model…

High Energy Astrophysical Phenomena · Physics 2015-06-16 Siyao Xu , Huirong Yan

In the standard Galactic cosmic-ray (CR) paradigm, protons are accelerated up to ~1 PeV by Galactic sources. While supernova remnants (SNRs) have been traditionally considered as the primary accelerators, recent observations by LHAASO and…

High Energy Astrophysical Phenomena · Physics 2026-01-22 Yutaka Fujita , Rohta Takahashi , Norita Kawanaka

One of the most essential but uncertain processes for producing cosmic-rays (CRs) and their spectra is how accelerated particles escape into the interstellar space. We propose that the CR electron spectra at >~TeV energy can provide a…

High Energy Astrophysical Phenomena · Physics 2015-04-23 Norita Kawanaka , Kunihito Ioka , Yutaka Ohira , Kazumi Kashiyama

Measuring the anisotropy of the arrival direction distribution of cosmic rays provides important information on the propagation mechanisms and the identification of their sources. In fact, the flux of cosmic rays is thought to be dependent…

High Energy Astrophysical Phenomena · Physics 2013-09-25 YBJ Collaboration

Recent efforts in cosmic ray (CR) confinement and transport theory are discussed. Three problems are addressed as being crucial for understanding the present day observations and their possible telltale signs of the CR origin. The first…

High Energy Astrophysical Phenomena · Physics 2016-10-11 M. A. Malkov

The paper investigates the overall and detailed features of cosmic ray (CR) spectra in the knee region using the scenario of nuclei-photon interactions around the acceleration sources. Young supernova remnants can be the physical realities…

High Energy Astrophysical Phenomena · Physics 2015-03-13 Bo Wang , Qiang Yuan , Chao Fan , Jianli Zhang , Hongbo Hu , Xiaojun Bi

Recent results of Milagro, Tibet, ARGO-YBJ and IceCube experiments on the small-scale anisotropy of Galactic cosmic rays (CRs) with energies from units up to a few hundred TeV arise a question on a possible nature of the observed…

High Energy Astrophysical Phenomena · Physics 2012-11-09 M. Yu. Zotov , G. V. Kulikov

We study the escape of cosmic-ray (CR) protons accelerated at a supernova remnant (SNR) by numerically solving a diffusion-convection equation from the vicinity of the shock front to the region far away from the front. We consider the…

High Energy Astrophysical Phenomena · Physics 2015-05-28 Yutaka Fujita , Fumio Takahara , Yutaka Ohira , Kazunari Iwasaki

Models for cosmic ray (CR) dynamics fundamentally depend on the rate of CR scattering from magnetic fluctuations. In the ISM, for CRs with energies ~MeV-TeV, these fluctuations are usually attributed either to 'extrinsic turbulence' (ET) -…

High Energy Astrophysical Phenomena · Physics 2022-11-10 Philip F. Hopkins , Jonathan Squire , Iryna S. Butsky , Suoqing Ji

Propagation of Galactic cosmic rays (CR) in the interstellar medium (ISM) is among the unsolved problems in particle astrophysics. Interpretation of CR spectrum and composition measurements and their possible link to dark matter crucially…

High Energy Astrophysical Phenomena · Physics 2020-09-11 Paolo Desiati , Juan Carlos Díaz Vélez , Nikolai Pogorelov , Ming Zhang

We calculate spectra of escaping cosmic rays (CRs) accelerated at shocks produced by expanding Galactic superbubbles powered by multiple supernovae producing a continuous energy outflow in star-forming galaxies. We solve the generalized…

High Energy Astrophysical Phenomena · Physics 2020-01-28 Zhaowei Zhang , Kohta Murase , Peter Mészáros