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This paper employs an MHD-PIC method to perform numerical simulations of magnetic reconnection-driven turbulence and turbulent reconnection acceleration of particles. Focusing on the dynamics of the magnetic reconnection, the properties of…

High Energy Astrophysical Phenomena · Physics 2023-07-26 Shiming Liang , Jianfu Zhang , Nana Gao , Huaping Xiao

We study the first-order Fermi acceleration process at parallel shock waves by means of Monte Carlo simulations. A 'realistic' model of the magnetic field turbulence is applied involving sinusoidal waves imposed on the background mean field…

Astrophysics · Physics 2007-05-23 Jacek Niemiec , Michal Ostrowski

We describe the theory of Fermi-type acceleration, including first-order Fermi acceleration at a parallel shock front and second-order Fermi acceleration in a test particle limit. Including the theory of the turbulent acceleration and the…

High Energy Astrophysical Phenomena · Physics 2018-07-11 Y. G. Zheng , G. B. Long , C. Y. Yang , J. M. Bai

The acceleration of charged particles in magnetized plasmas is considered during turbulent multi-island magnetic reconnection. The particle acceleration model is constructed for an ensemble of islands which produce adiabatic compression of…

Solar and Stellar Astrophysics · Physics 2015-06-15 Nicolas Bian , Eduard Kontar

We investigate acceleration and propagation processes of high-energy particles inside hot accretion flows. The magnetorotational instability (MRI) creates turbulence inside accretion flows, which triggers magnetic reconnection and may…

High Energy Astrophysical Phenomena · Physics 2019-12-03 Shigeo S. Kimura , Kengo Tomida , Kohta Murase

Astrophysical reconnection takes place in a turbulent medium. The turbulence in most cases is pre-existing, not caused by the reconnection itself. The model of magnetic reconnection in Lazarian & Vishniac (1999) predicts that in the…

High Energy Astrophysical Phenomena · Physics 2012-02-09 A. Lazarian , G. Kowal , B. Gouveia dal Pino

We present the first study of the multiscaling of time-dependent velocity and magnetic-field structure functions in homogeneous, isotropic magnetohydrodynamic (MHD) turbulence in three dimensions. We generalize the formalism that has been…

Fluid Dynamics · Physics 2016-11-08 Samriddhi Sankar Ray , Ganapati Sahoo , Rahul Pandit

When a particle crosses a region of space where the curvature radius of the magnetic field line shrinks below its gyroradius $r_{\rm g}$, it experiences a non-adiabatic (magnetic moment violating) change in pitch angle. The present paper…

Plasma Physics · Physics 2023-09-15 Martin Lemoine

Relativistic sources, e.g. gamma-ray bursts, pulsar wind nebulae and powerful active galactic nuclei produce relativistic outflows that lead to the formation of collisionless shock waves, where particle acceleration is thought to take…

High Energy Astrophysical Phenomena · Physics 2015-06-03 Martin Lemoine , Guy Pelletier

Particles are accelerated to very high, non-thermal energies during explosive energy-release phenomena in space, solar, and astrophysical plasma environments. While it has been established that magnetic reconnection plays an important role…

Our numerical simulations show that the reconnection of magnetic field becomes fast in the presence of weak turbulence in the way consistent with the Lazarian and Vishniac (1999) model of fast reconnection. We trace particles within our…

Astrophysics of Galaxies · Physics 2015-05-18 A. Lazarian , G. Kowal , E. Vishniac , E. de Gouveia dal Pino

Hot accretion flows contain collisionless plasmas that are believed to be capable of accelerating particles to very high energies, as a result of turbulence generated by the magnetorotational instability (MRI). We conduct unstratified…

High Energy Astrophysical Phenomena · Physics 2021-07-14 Xiaochen Sun , Xue-Ning Bai

One of the main features of astrophysical shocks is their ability to accelerate particles to extremely high energies. The leading acceleration mechanism, the diffusive shock acceleration is reviewed. It is demonstrated that its efficiency…

Astrophysics · Physics 2009-11-06 M. A. Malkov , P. H. Diamond

Astrophysical fluids are turbulent, magnetized and frequently partially ionized. As an example of astrophysical turbulence, the interstellar turbulence extends over a remarkably large range of spatial scales and participates in key…

Astrophysics of Galaxies · Physics 2018-10-22 Siyao Xu , Alex Lazarian

We analyze the transport properties of charged particles (ions and electrons) interacting with randomly formed magnetic scatterers (e.g.\ large scale local ``magnetic fluctuations'' or ``coherent magnetic irregularities'' usually present in…

Solar and Stellar Astrophysics · Physics 2020-01-08 Nikos Sioulas , Heinz Isliker , Loukas Vlahos , Argyris Koumtzis , Theophilos Pisokas

First order Fermi acceleration at astrophysical shocks is often invoked as a mechanism for the generation of non-thermal particles. This mechanism is especially simple in the approximation that the accelerated particles behave like test…

Astrophysics · Physics 2015-06-24 Pasquale Blasi

This paper presents numerical simulations of test particle Fermi acceleration at relativistic shocks of Lorentz factor Gamma_sh = 2-60, using a realistic downstream magnetic structure obtained from the shock jump conditions. The upstream…

Astrophysics · Physics 2009-11-13 Martin Lemoine , Benoit Revenu

We numerically investigate a crucial parameter for understanding particle acceleration theory via turbulence-induced magnetic reconnection: the particle acceleration time. We examine particles accelerated either during the jet's dynamic…

High Energy Astrophysical Phenomena · Physics 2026-05-20 Elisabete M. de Gouveia Dal Pino , Tania E. Medina-Torrejon

We investigate the Fermi acceleration of charged particles in 2D MHD anti-parallel plasmoid reconnection, finding a drastic enhancement in energization rate $\dot{\varepsilon}$ over a standard Fermi model of $\dot{\varepsilon} \sim…

Plasma Physics · Physics 2023-04-26 Stephen Majeski , Hantao Ji

We investigate the physics of particle acceleration at non-relativistic shocks exploiting two different and complementary approaches, namely a semi-analytic modeling of cosmic-ray modified shocks and large hybrid (kinetic protons/fluid…

High Energy Astrophysical Phenomena · Physics 2015-06-11 Damiano Caprioli