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Cosmic rays (CRs) are thought to be accelerated in SNRs. The most favorable situation for proving that the main, hadronic CR component is accelerated there is when CRs interact with dense gases, such as molecular clouds (MC) which surround…

Astrophysics · Physics 2009-11-10 M. A. Malkov , P. H. Diamond , R. Z. Sagdeev

Recently, the gamma-ray telescopes AGILE and Fermi observed several middle-aged supernova remnants (SNRs) interacting with molecular clouds. A plausible emission mechanism of the gamma rays is the decay of neutral pions produced by cosmic…

High Energy Astrophysical Phenomena · Physics 2015-05-27 Yutaka Ohira , Kazunori Kohri , Norita Kawanaka

Hadronic gamma-ray emission from supernova remnants (SNRs) is an important tool to test shock acceleration of cosmic ray protons. Tycho is one of nearly a dozen Galactic SNRs which are suggested to emit hadronic gamma-ray emission. Among…

High Energy Astrophysical Phenomena · Physics 2015-06-11 Xiao Zhang , Yang Chen , Hui Li , Xin Zhou

We perform kinetic simulations of diffusive shock acceleration (DSA) in Type Ia supernova remnants (SNRs) expanding into a uniform interstellar medium (ISM). Bohm-like diffusion assumed, and simple models for Alfvenic drift and dissipation…

High Energy Astrophysical Phenomena · Physics 2017-01-18 Hyesung Kang

A new numerical model of the nonlinear diffusive shock acceleration is presented. It is used for modeling of particle acceleration in supernova remnants. The model contains coupled spherically symmetric hydrodynamic equations and the…

High Energy Astrophysical Phenomena · Physics 2015-05-30 V. N. Zirakashvili , V. S. Ptuskin

We argue that the anomalously high fluxes of positrons and antiprotons found in cosmic rays (CR) can be satisfactorily explained by introducing two additional elements to the current "standard" paradigm of Galactic CRs. First, we propose…

High Energy Astrophysical Phenomena · Physics 2019-10-09 Rui-zhi Yang , Felix Aharonian

Without amplification, magnetic fields in expanding ejecta of young supernova remnants (SNRs) will be orders of magnitude below those required to shock accelerate thermal electrons, or ions, to relativistic energies or to produce radio…

Astrophysics · Physics 2009-11-10 Donald C. Ellison , Anne Decourchelle , Jean Ballet

It is widely believe that galactic cosmic rays are originated in supernova remnants (SNRs) where they are accelerated by diffusive shock acceleration process at supernova blast waves driven by expanding SNRs. In recent theoretical…

High Energy Astrophysical Phenomena · Physics 2017-08-02 Prabir Banik , Arunava Bhadra

Electron(positron), proton and nuclei can be accelerated to very high energy by local supernova remnants (SNR). The famous excesses of electron and proton (nuclei) potentially come from such kind of local sources. Recently, the DAMPE…

High Energy Astrophysical Phenomena · Physics 2023-11-20 Jin-tao Wu , Ming-jun Feng , Jian-hong Ruan

The idea that the shocks from supernova remnants (SNR) expanding into the interstellar medium (ISM) accelerate CR is still popular one but a number of authors have drawn attention to the fact that the experimental evidence for the presence…

Astrophysics · Physics 2008-11-26 A. D. Erlykin , A. W. Wolfendale

Nonlinear kinetic theory of cosmic ray (CR) acceleration in supernova remnants is employed to calculate CR spectra. The magnetic field in SNRs is assumed to be significantly amplified by the efficiently accelerating nuclear CR component. It…

Astrophysics · Physics 2009-11-13 E. G. Berezhko , H. J. Voelk

Spectrum and chemical composition of cosmic rays accelerated in supernova remnants are studied on a basis of kinetic approach. The cosmic ray transport equation with the Bohm diffusion coefficient has been numerically solved…

Astrophysics · Physics 2008-02-03 E. G. Berezhko , G. F. Krymsky , V. K. Yelshin , L. T. Ksenofontov

Secondary positrons are produced by spallation of cosmic rays within the interstellar gas. Measurements have been typically expressed in terms of the positron fraction, which exhibits an increase above 10 GeV. Many scenarios have been…

Astrophysics · Physics 2009-10-06 T. Delahaye , F. Donato , N. Fornengo , J. Lavalle , R. Lineros , P. Salati , R. Taillet , .

While supernova remnants (SNRs) have long been considered prime candidates for the source of cosmic rays, at least to energies up to ~10^14 eV, it is only over the past several years that direct evidence of such energetic particles in SNRs…

Astrophysics · Physics 2007-05-23 Patrick Slane

We recently found that streaming cosmic rays (CRs) induce a resistive electric field that can accelerate secondary electrons produced by CR ionization. In this work, we study the evolution of the energy spectrum of secondary electrons by…

High Energy Astrophysical Phenomena · Physics 2024-06-26 Yutaka Ohira

The Alpha Magnetic Spectrometer has released high-precision data for cosmic rays, and has verified an excess of positrons relative to expectations from cosmic ray interactions in the interstellar medium. An exciting and well-known…

High Energy Astrophysical Phenomena · Physics 2017-02-22 M. Kruskal , S. P. Ahlen , G. Tarlé

Sufficiently strong electric fields in plasmas can accelerate charged particles to relativistic energies. In this paper we describe the dynamics of positrons accelerated in such electric fields, and calculate the fraction of created…

Plasma Physics · Physics 2018-11-07 Ola Embréus , Linnea Hesslow , Mathias Hoppe , Gergely Papp , Katya Richards , Tünde Fülöp

Supernova remnants (SNRs) interacting with molecular clouds are interesting laboratories to study the acceleration of cosmic rays and their propagation in the dense ambient medium. We analyze 14 years of Fermi-LAT observations of the…

Diffusive shock acceleration in supernova remnants (SNRs) is considered one of the prime mechanisms for Galactic Cosmic Ray (GCR) acceleration. It is still unclear, however, whether SNRs can contribute to GCR spectrum up to the ``knee''…

High Energy Astrophysical Phenomena · Physics 2023-12-06 Victor Doroshenko , Gerd Pühlhofer , Andrea Santangelo

The spectra of high-energy protons and nuclei accelerated by supernova remnant shocks are calculated taking into account magnetic field amplification and Alfvenic drift both upstream and downstream of the shock for different types of…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-19 V. S. Ptuskin , V. N. Zirakashvili , E. S. Seo
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