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Collisionless shocks are often studied in two spatial dimensions (2D), to gain insights into the 3D case. We analyze diffusive shock acceleration for an arbitrary number $N\in\mathbb{N}$ of dimensions. For a non-relativistic shock of…

High Energy Astrophysical Phenomena · Physics 2020-07-07 Assaf Lavi , Ofir Arad , Yotam Nagar , Uri Keshet

Shear flows are ubiquitously present in space and astrophysical plasmas. This paper highlights the central idea of the non-thermal acceleration of charged particles in shearing flows and reviews some of the recent developments. Topics…

High Energy Astrophysical Phenomena · Physics 2019-09-17 Frank M. Rieger

Context. Solar energetic particles observed in association with coronal mass ejections (CMEs) are produced by the CME-driven shock waves. The acceleration of particles is considered to be due to diffusive shock acceleration (DSA). Aims. We…

Space Physics · Physics 2016-03-30 Alexandr Afanasiev , Markus Battarbee , Rami Vainio

The linear theory of shock acceleration predicts the maximum particle energy to be limited only by the acceleration time and the size of the shock. We study the combined effect of acceleration nonlinearity (shock modification by accelerated…

Astrophysics · Physics 2007-05-23 M. A. Malkov , P. H. Diamond , T. W. Jones

Particle acceleration in collisionless shocks is believed to be responsible for the production of cosmic-rays over a wide range of energies, from few GeV to >10^{20}eV, as well as for the non-thermal emission of radiation from a wide…

Astrophysics · Physics 2009-11-11 E. Waxman

We report studies on first-order Fermi acceleration in parallel modified shock waves with a large scattering center compression ratio expected from turbulence transmission models. Using a Monte Carlo technique we have modeled particle…

Astrophysics · Physics 2009-11-11 Joni J. P. Virtanen , Rami Vainio

Our purpose is to evaluate the rate of the maximum energy and the acceleration rate that cosmic rays acquire in the non-relativistic diffusive shock acceleration as it could apply during their lifetime in various astrophysical sites, where…

Astrophysics · Physics 2009-11-11 A. Meli , P. L. Biermann

Particle acceleration is expected to take place at shocks that form during the process of large scale structure formation. Electrons accelerated at such shocks can upscatter a small fraction of the photons in the cosmic microwave background…

Astrophysics · Physics 2007-05-23 Stefano Gabici

Electron acceleration in collisionless shocks with arbitrary magnetic field orientations is discussed. It is shown that the injection of thermal electrons into diffusive shock acceleration process is achieved by an electron beam with a…

High Energy Astrophysical Phenomena · Physics 2010-05-25 Takanobu Amano , Masahiro Hoshino

When supersonic plasma flows collide, many physical processes contribute to the morphology of the resulting shock. One of these processes is the acceleration of non-thermal ions, which will, eventually, reach relativistic speeds and become…

High Energy Astrophysical Phenomena · Physics 2025-09-16 Allard Jan van Marle

Diffusive shock acceleration in the environs of a remnant's expanding shell is a popular candidate for the origin of SNR gamma-rays. In this paper, results from our study of non-linear effects in shock acceleration theory and their impact…

In this paper, we develop a model for the radio and X-ray emissions from Type IIb Supernova (SN IIb) 2011dh in the first 100 days after the explosion, and investigate a spectrum of relativistic electrons accelerated at a strong shock wave.…

High Energy Astrophysical Phenomena · Physics 2015-06-11 Keiichi Maeda

Collisionless shocks are pervasive in astrophysics and they are critical to understand cosmic ray acceleration. Laboratory experiments with intense lasers are now opening the way to explore and characterise the underlying microphysics,…

Plasma Physics · Physics 2014-01-14 A. Stockem , F. Fiuza , A. Bret , R. A. Fonseca , L. O. Silva

Diffusive shock acceleration and diffusion propagation are essential components of the standard cosmic ray model. These theories are based on extensive observations of high-energy solar processes, providing substantial direct evidence in…

High Energy Astrophysical Phenomena · Physics 2026-05-19 Weikang Gao , Li-Zhuo Bao , Kun Fang , En-sheng Chen , Siming Liu , HongBo Hu

The theory of particle acceleration at shock fronts is briefly reviewed, with special emphasis on the production of the particles responsible for the nonthermal emission from blazars. The flat radio/IR spectra of these sources cannot be…

Astrophysics · Physics 2007-05-23 J. G. Kirk

We present a new code aimed at the simulation of diffusive shock acceleration (DSA), and discuss various test cases which demonstrate its ability to study DSA in its full time-dependent and non-linear developments. We present the numerical…

Astrophysics · Physics 2009-11-13 Gilles Ferrand , Turlough Downes , Alexandre Marcowith

Dissipative processes cause collisionless plasmas in many systems to develop nonthermal particle distributions with broad power-law tails. The prevalence of power-law energy distributions in space/astrophysical observations and kinetic…

High Energy Astrophysical Phenomena · Physics 2022-07-06 Vladimir Zhdankin

Recent observations of excess radiation at extreme ultraviolet and hard X-ray energies straddling the well known thermal soft X-ray emission have provided new tools and puzzles for investigation of the acceleration of nonthermal particles…

Astrophysics · Physics 2007-05-23 Vahé Petrosian

The much-anticipated proof of cosmic ray (CR) acceleration in supernova remnants (SNR) must hinge on full consistency of acceleration theory with the observations; direct proof is impossible because of the orbit scrambling of CR particles.…

Astrophysics of Galaxies · Physics 2012-03-19 M. A. Malkov , P. H. Diamond , R. Z. Sagdeev

We present a three-dimensional hybrid simulation of a collisionless perpendicular shock in a partially ionized plasma for the first time. In this simulation, the shock velocity and the upstream ionization fraction are Vsh ~ 1333 km/s and fi…

High Energy Astrophysical Phenomena · Physics 2016-08-17 Yutaka Ohira