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Related papers: Super-Fermi Acceleration in Multiscale MHD Reconne…

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The aim of this work is to investigate and characterise particle behaviour in a 3D magnetohydrodynamic (MHD) model of a reconnecting magnetic separator. We use a relativistic guiding-centre test-particle code to investigate electron and…

Solar and Stellar Astrophysics · Physics 2015-12-23 J. Threlfall , J. E. H. Stevenson , C. E. Parnell , T. Neukirch

Magnetic reconnection is often considered as the primary particle acceleration mechanism in a magnetized blazar zone environment. The majority of radiation in the reconnection layer comes from plasmoids and their mergers. In particular,…

High Energy Astrophysical Phenomena · Physics 2024-06-18 Haocheng Zhang , Lingyi Dong , Dimitrios Giannios

Plasmoids -- magnetized quasi-circular structures formed self-consistently in reconnecting current sheets -- were previously considered to be the graveyards of energetic particles. In this paper, we demonstrate the important role of…

High Energy Astrophysical Phenomena · Physics 2021-05-06 Hayk Hakobyan , Maria Petropoulou , Anatoly Spitkovsky , Lorenzo Sironi

While the exact acceleration mechanism of energetic particles during solar flares is (as yet) unknown, magnetic reconnection plays a key role both in the release of stored magnetic energy of the solar corona and the magnetic restructuring…

Solar and Stellar Astrophysics · Physics 2015-01-21 J. Threlfall , T. Neukirch , C. E. Parnell , S. Eradat Oskoui

It has been proposed that particles bouncing between magnetized flows converging in a reconnection region can be accelerated by the first order Fermi mechanism. Analytical considerations of this mechanism have shown that the spectral index…

Space Physics · Physics 2016-07-06 Elena Provornikova , John Martin Laming , Vyacheslav S. Lukin

Electron acceleration during magnetic reconnection is thought to play a key role in time-variable high-energy emission from astrophysical systems. By means of particle-in-cell simulations of trans-relativistic reconnection, we investigate…

High Energy Astrophysical Phenomena · Physics 2019-10-16 David Ball , Lorenzo Sironi , Feryal Özel

The acceleration of ultra high energy cosmic rays is conjectured to occur through various interactions with the electromagnetic fields in different astrophysical objects, like magnetic matter clumps, besides the well-known shock and…

High Energy Astrophysical Phenomena · Physics 2014-03-18 A. Tawfik , A. Saleh , M. T. Ghoneim , A. A. Hady

Astrophysical media are turbulent and therefore reconnection should be treated in the presence of pre-existing turbulence. We consider the model of fast magnetic reconnection in Lazarian & Vishniac (1999) which predicts that the rate of…

Astrophysics of Galaxies · Physics 2015-06-05 A. Lazarian , G. Kowal , E. Gouveia dal Pino , E. Vishniac

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

Imagine a swarm of free particles near a point P outside a gravitating mass M and a free reference particle at P that is on a radial escape trajectory away from M. Relative to this reference particle and in a Fermi normal coordinate system…

Astrophysics · Physics 2015-10-28 C. Chicone , B. Mashhoon

First-order Fermi acceleration processes at ultrarelativistic shocks are studied with Monte Carlo simulations. The accelerated particle spectra are derived by integrating the exact particle trajectories in a turbulent magnetic field near…

Astrophysics · Physics 2009-11-13 Jacek Niemiec , Michal Ostrowski

We investigate shock structure and particle acceleration in relativistic magnetized collisionless pair shocks by means of 2.5D and 3D particle-in-cell simulations. We explore a range of inclination angles between the pre-shock magnetic…

High Energy Astrophysical Phenomena · Physics 2011-02-11 Lorenzo Sironi , Anatoly Spitkovsky

Magnetic reconnection is invoked as an efficient particle accelerator in a variety of astrophysical sources of non-thermal high-energy radiation. With large-scale two-dimensional particle-in-cell simulations of relativistic reconnection…

High Energy Astrophysical Phenomena · Physics 2018-10-17 Maria Petropoulou , Lorenzo Sironi

Observations of galaxy clusters show radio emission extended over almost the system scale, necessitating mechanisms for particle acceleration. Previous models for acceleration such as diffusive shock acceleration and that due to turbulence…

Cosmology and Nongalactic Astrophysics · Physics 2025-01-30 Subham Ghosh , Pallavi Bhat

Cosmic Ray (CR) acceleration still challenges the researchers. Fast particles may be accelerated in astrophysical environments by a variety of processes. Acceleration in magnetic reconnection sites in particular, has lately attracted the…

High Energy Astrophysical Phenomena · Physics 2014-01-21 Elisabete M. de Gouveia Dal Pino , Grzegorz Kowal , Alex Lazarian

We propose that non-thermal electrons are efficiently accelerated by first-order Fermi process at the fast shock, as a natural consequence of the new magnetohydrodynamic picture of the flaring region revealed with Yohkoh. An oblique fast…

Astrophysics · Physics 2009-10-30 Saku Tsuneta , Tsuguya Naito

A rotating pulsar creates a surrounding pulsar wind nebula (PWN) by steadily releasing an energetic wind into the interior of the expanding shockwave of supernova remnant or interstellar medium. At the termination shock of a PWN, the…

Plasma Physics · Physics 2020-07-15 Yingchao Lu , Fan Guo , Patrick Kilian , Hui Li , Chengkun Huang , Edison Liang

Electron energization by magnetic reconnection has historically been studied in the Lagrangian guiding-center framework. Insights from such studies include that Fermi acceleration in magnetic islands can accelerate electrons to high…

Plasma Physics · Physics 2025-05-28 Konrad Steinvall , Louis Richard , Tünde Fülöp , Lise Hanebring , István Pusztai

Magnetic reconnection is an important driver of energetic particles in many astrophysical phenomena. Using kinetic particle-in-cell (PIC) simulations, we explore the impact of three-dimensional reconnection dynamics on the efficiency of…

Plasma Physics · Physics 2017-10-11 J. T. Dahlin , J. F. Drake , M. Swisdak

Magnetic reconnection can power bright, rapid flares originating from the inner magnetosphere of accreting black holes. We conduct extremely high resolution ($5376\times2304\times2304$ cells) general-relativistic magnetohydrodynamics…

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