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Related papers: Re-acceleration of Cosmic Ray Electrons by Multipl…

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We use kinetic simulations of diffusive shock acceleration (DSA) to study the time-dependent evolution of plane, quasi-parallel, cosmic-ray (CR) modified shocks. Thermal leakage injection of low energy CRs and finite Alfv\'en wave…

High Energy Astrophysical Phenomena · Physics 2011-02-11 Hyesung Kang , Dongsu Ryu , T. W. Jones

We propose semi-analytic models for the electron momentum distribution in weak shocks that accounts for both in situ acceleration and re-acceleration through diffusive shock acceleration (DSA). In the former case, a small fraction of…

High Energy Astrophysical Phenomena · Physics 2020-11-25 Hyesung Kang

Diffusive shock acceleration (DSA) at relativistic shocks is expected to be an important acceleration mechanism in a variety of astrophysical objects including extragalactic jets in active galactic nuclei and gamma ray bursts. These sources…

High Energy Astrophysical Phenomena · Physics 2014-11-20 Matthew G. Baring , Errol J. Summerlin

In order for diffusive shock acceleration (DSA) to accelerate particles to high energies, the energetic particles must be able to interact with magnetic turbulence over a broad wavelength range. The weakly anisotropic distribution of…

High Energy Astrophysical Phenomena · Physics 2015-05-20 A. M. Bykov , S. M. Osipov , D. C. Ellison

A rapidly growing amount of evidences, mostly coming from the recent gamma-ray observations of Galactic supernova remnants (SNRs), is seriously challenging our understanding of how particles are accelerated at fast shocks. The cosmic-ray…

High Energy Astrophysical Phenomena · Physics 2015-06-05 Damiano Caprioli

We study diffusive shock acceleration (DSA) of electrons in non-relativistic quasi-perpendicular shocks using self-consistent one-dimensional particle-in-cell (PIC) simulations. By exploring the parameter space of sonic and Alfv\'{e}nic…

High Energy Astrophysical Phenomena · Physics 2020-07-22 Rui Xu , Anatoly Spitkovsky , Damiano Caprioli

We simulate the evolution of relativistic electrons injected into the medium of a small galaxy cluster by a central radio galaxy, studying how the initial jet power affects the dispersal and the emission properties of radio plasma. By…

High Energy Astrophysical Phenomena · Physics 2023-01-04 F. Vazza , D. Wittor , L. Di Federico , M. Brüggen , M. Brienza , G. Brunetti , F. Brighenti , T. Pasini

Context. The diffusive shock acceleration mechanism has been widely accepted as the acceleration mechanism for galactic cosmic rays. While self-consistent hybrid simulations have shown how power-law spectra are produced, detailed…

High Energy Astrophysical Phenomena · Physics 2015-06-04 M. Wolff , R. C. Tautz

Diffusive shock acceleration (DSA), as an acceleration process for Galactic electrons at the solar wind termination shock (TS), is investigated with a comprehensive numerical model which incorporates shock-acceleration, particle drifts and…

Space Physics · Physics 2017-11-30 M. S. Potgieter , P. L. Prinsloo , R. D. Strauss

Radio relics are giant sources of diffuse synchrotron radio emission in the outskirts of galaxy clusters that are associated with shocks in the intracluster medium. Still, the origin of relativistic particles that make up relics is not…

Cosmology and Nongalactic Astrophysics · Physics 2023-10-10 David C. Smolinski , Denis Wittor , Franco Vazza , Marcus Brüggen

Cosmic ray (CR) spectra, both measured upon their arrival at the Earth's atmosphere and inferred from the emission in supernova remnants (SNRs), appear to be significantly steeper than the "standard" diffusive shock acceleration (DSA)…

High Energy Astrophysical Phenomena · Physics 2019-11-06 Adrian Hanusch , Tatyana V. Liseykina , Mikhail Malkov , Felix Aharonian

Galactic cosmic rays (CR) are particles presumably accelerated in supernova remnant shocks that propagate in the interstellar medium up to the densest parts of molecular clouds, losing energy and their ionisation efficiency because of the…

High Energy Astrophysical Phenomena · Physics 2016-05-25 M. Padovani , A. Marcowith , P. Hennebelle , K. Ferrière

We explore how wave-particle interactions affect diffusive shock acceleration (DSA) at astrophysical shocks by performing time-dependent kinetic simulations, in which phenomenological models for magnetic field amplification (MFA), Alfvenic…

High Energy Astrophysical Phenomena · Physics 2015-06-11 Hyesung Kang

Galactic cosmic rays are widely believed to be accelerated in expanding shock waves initiated by supernova explosions. The theory of diffusive shock acceleration of cosmic rays is now well established, but two fundamental questions remain…

Astrophysics · Physics 2008-07-25 Vincent Tatischeff

In addition to electrons and protons, nonrelativistic quasiparallel shocks are expected to possess the ability to accelerate heavy ions. The shocks in supernova remnants are generally supposed to be accelerators of the Galactic cosmic rays,…

High Energy Astrophysical Phenomena · Physics 2022-04-20 Jun Fang , Qi Xia , Shiting Tian , Liancheng Zhou , Huan Yu

This study investigates the impact of magnetic turbulence on cosmic ray (CR) electrons through Fermi-II acceleration behind merger-driven shocks in the intracluster medium and examines how the ensuing synchrotron radio emission is…

High Energy Astrophysical Phenomena · Physics 2024-05-07 Hyesung Kang

Diffusive shock acceleration is the theory of particle acceleration through multiple shock crossings. In order for this process to proceed at a rate that can be reconciled with observations of high-energy electrons in the vicinity of the…

High Energy Astrophysical Phenomena · Physics 2015-06-04 K. M. Schure , A. R. Bell , L. O'C Drury , A. M. Bykov

Cosmological hydrodynamic simulations of large scale structure in the universe have shown that accretion shocks and merger shocks form due to flow motions associated with the gravitational collapse of nonlinear structures. Estimated speed…

Astrophysics · Physics 2015-06-24 Hyesung Kang , T. W. Jones

We investigate the production of cosmic ray (CR) protons at cosmological shocks by performing, for the first time, numerical simulations of large scale structure formation that include directly the acceleration, transport and energy losses…

Astrophysics · Physics 2009-11-06 Francesco Miniati , Dongsu Ryu , Hyesung Kang , T. W. Jones

We study diffusive shock acceleration (DSA) of protons and electrons at nonrelativistic, high Mach number, quasiparallel, collisionless shocks by means of self-consistent 1D particle-in-cell simulations. For the first time, both species are…

High Energy Astrophysical Phenomena · Physics 2015-03-02 Jaehong Park , Damiano Caprioli , Anatoly Spitkovsky