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Related papers: Shock acceleration with oblique and turbulent magn…

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A major attraction of diffusive shock acceleration is the prediction of power-law spectra for energetic particle distributions. However, this property is not fundamental to the theory. We demonstrate that for planar shocks with an oblique…

High Energy Astrophysical Phenomena · Physics 2025-11-04 Asma Shirin T , Brian Reville , Nils W. Schween , Florian Schulze , John G. Kirk

To undergo diffusive shock acceleration, electrons need to be pre-accelerated to increase their energies by several orders of magnitude, else their gyro-radii are smaller than the finite width of the shock. In oblique shocks, where the…

Plasma Physics · Physics 2022-06-08 Paul J. Morris , Artem Bohdan , Martin S. Weidl , Martin Pohl

We use large hybrid (kinetic protons-fluid electrons) simulations to investigate the transport of energetic particles in self-consistent electromagnetic configurations of collisionless shocks. In previous papers of this series, we showed…

High Energy Astrophysical Phenomena · Physics 2015-06-22 Damiano Caprioli , Anatoly Spitkovsky

We investigate the growth of hydromagnetic waves driven by streaming cosmic rays in the precursor environment of a supernova remnant shock. It is known that transverse waves propagating parallel to the mean magnetic field are unstable to…

Astrophysics · Physics 2009-11-13 B. Reville , J. G. Kirk , P. Duffy , S. O. Sullivan

Kinetic approaches provide an effective description of the process of particle acceleration at shock fronts and allow to take into account the dynamical reaction of the accelerated particles as well as the amplification of the turbulent…

Astrophysics · Physics 2009-11-13 Elena Amato , Pasquale Blasi , Stefano Gabici

The instability in the cosmic-ray precursor of a supernova shock moving in interstellar medium is studied. The level of magnetohydrodynamic turbulence in this region determines the maximum energy of particles accelerated by the diffusive…

Astrophysics · Physics 2011-05-23 V. S. Ptuskin , V. N. Zirakashvili

Charged particles in a magnetosphere are spontaneously attracted to a planet while increasing their kinetic energy via inward diffusion process. A constraint on particles' micro-scale adiabatic invariants restricts the class of motions…

Plasma Physics · Physics 2016-11-08 Y. Ushida , Y. Kawazura , N. Sato , Z. Yoshida

The process of cosmic ray first-order Fermi acceleration at relativistic shock waves is studied with the method of Monte Carlo simulations. The simulations are based on numerical integration of particle equations of motion in a turbulent…

Astrophysics · Physics 2009-11-10 Jacek Niemiec , Michal Ostrowski

Recent advances in understanding of magnetohydrodynamic (MHD) turbulence call for revisions in the picture of particle acceleration. We make use of the recently established scaling of slow and fast MHD modes in strong and weak MHD…

Astrophysics · Physics 2016-08-30 Jungyeon Cho , A. Lazarian

The study of dynamo action in astrophysical objects classically involves two timescales: the slow diffusive one and the fast advective one. We investigate the possibility of field amplification on an intermediate timescale associated with…

Classical Physics · Physics 2009-11-13 Emmanuel Dormy , David Gerard-Varet

We are concerned with large scale magnetic field dynamo generation and propagation of magnetic fronts in turbulent electrically conducting fluids. An effective equation for the large scale magnetic field is developed here that takes into…

Astrophysics · Physics 2009-11-06 Sergei Fedotov , Alexey Ivanov , Andrey Zubarev

A joint effect of the density-stratified turbulence (or inhomogeneous turbulence) and a large-scale shear for arbitrary Mach numbers results in the $\alpha$ effect and mean-field dynamo action. These effects also produce the effective…

Astrophysics of Galaxies · Physics 2026-03-19 Igor Rogachevskii , Nathan Kleeorin

Magnetic reconnection is commonly perceived to drive flow and particle acceleration in flares of solar, stellar, and astrophysical disk coronae but the relative roles of different acceleration mecha- nisms in a given reconnection…

High Energy Astrophysical Phenomena · Physics 2015-05-28 Jared C. Workman , Eric G. Blackman , Chuang Ren

If taken into account, the transmission of the particle-scattering turbulence --in addition to just the particles-- through the shock front can change the effective compression ratio felt by the accelerating particles significantly from the…

Astrophysics · Physics 2007-12-12 Joni Tammi

It is shown that acceleration of particles in a homogeneous magnetic field that varies periodically with time (Alfven magnetic pumping) reduces to a diffusion of the particles in momentum space; a connection is established between the…

Accelerator Physics · Physics 2018-01-03 M. A. Kutlan

Nonthermal acceleration of particles in magnetohydrodynamic (MHD) turbulence plays a central role in a wide variety of astrophysical sites. This physics is addressed here in the context of a strong turbulence, composed of coherent…

High Energy Astrophysical Phenomena · Physics 2021-10-06 Martin Lemoine

The present article investigates magnetic amplification in the upstream medium of SNR blast wave through both resonant and non-resonant regimes of the streaming instability. It aims at a better understanding of the diffusive shock…

High Energy Astrophysical Phenomena · Physics 2015-05-14 A. Marcowith , F. Casse

We show that an alpha effect is driven by the cosmic ray Bell instability exciting left-right asymmetric turbulence. Alfven waves of a preferred polarization have maximally helical motion, because the transverse motion of each mode is…

High Energy Astrophysical Phenomena · Physics 2012-06-21 Igor Rogachevskii , Nathan Kleeorin , Axel Brandenburg , David Eichler

The radiation drag in photon-rich environments of cosmic explosions can seed kinetic instabilities by inducing velocity spreads between relativistically streaming plasma components. Such microturbulence is likely imprinted on the breakout…

High Energy Astrophysical Phenomena · Physics 2023-01-25 J. F. Mahlmann , A. Vanthieghem , A. A. Philippov , A. Levinson , E. Nakar , F. Fiuza

The diffusion of astrophysical magnetic fields in conducting fluids in the presence of turbulence depends on whether magnetic fields can change their topology or reconnect in highly conducting media. Recent progress in understanding fast…

Astrophysics of Galaxies · Physics 2010-03-16 A. Lazarian , R. Santos-Lima , E. Gouveia Dal Pino