English
Related papers

Related papers: Stochastic Acceleration in Turbulent Electric Fiel…

200 papers

We study the physics of electron acceleration at collisionless shocks that move through a plasma containing large-scale magnetic fluctuations. We numerically integrate the trajectories of a large number of electrons, which are treated as…

Solar and Stellar Astrophysics · Physics 2015-03-13 Fan Guo , Joe Giacalone

We investigate shock structure and particle acceleration in relativistic magnetized collisionless electron-ion shocks by means of 2.5D particle-in-cell simulations with ion-to-electron mass ratios (m_i/m_e) ranging from 16 to 1000. We…

High Energy Astrophysical Phenomena · Physics 2015-05-19 Lorenzo Sironi , Anatoly Spitkovsky

Classical Sweet-Parker models of reconnection predict that reconnection rates depend inversely on the resistivity, usually parameterized using the dimensionless Lundquist number ($\Lund$). We describe magnetohydrodynamic (MHD) simulations…

Solar and Stellar Astrophysics · Physics 2015-06-11 Jeffrey S. Oishi , Mordecai-Mark Mac Low , David C. Collins , Moeko Tamura

The fully three dimensional governing equations in the electron magnetohydrodynamic (EMHD) regime for a plasma with inhomogeneous density is obtained. These equations in the two dimensional (2-D) limit can be cast in terms of the evolution…

Plasma Physics · Physics 2009-11-13 Sharad Kumar Yadav , Amita Das , Predhiman Kaw

Context. The magnetic field in the solar atmosphere continually reconnects and accelerates charged particles to high energies. Simulations of the atmosphere in three dimensions that include the effects of accelerated particles can aid our…

Solar and Stellar Astrophysics · Physics 2022-10-05 L. Frogner , B. V. Gudiksen

Collisionless, magnetized turbulence offers a promising framework for the generation of non-thermal high-energy particles in various astrophysical sites. Yet, the detailed mechanism that governs particle acceleration has remained subject to…

High Energy Astrophysical Phenomena · Physics 2022-08-17 Virginia Bresci , Martin Lemoine , Laurent Gremillet , Luca Comisso , Lorenzo Sironi , Camilia Demidem

We use 3D fully kinetic particle-in-cell simulations to study the occurrence of magnetic reconnection in a simulation of decaying turbulence created by anisotropic counter-propagating low-frequency Alfv\'en waves consistent with…

Electron acceleration mechanism at high Mach number collisionless shocks propagating in a weakly magnetized medium is investigated by a self-consistent two-dimensional particle-in-cell simulation. Simulation results show that strong…

Astrophysics · Physics 2008-12-18 Takanobu Amano , Masahiro Hoshino

Magnetic reconnection in laboratory, space and astrophysical plasmas is often invoked to explain explosive energy release and particle acceleration. However, the timescales involved in classical models within the macroscopic MHD regime are…

Plasma Physics · Physics 2016-12-21 S. Landi , E. Papini , L. Del Zanna , A. Tenerani , F. Pucci

Turbulence is often invoked to explain the origin of nonthermal particles in space and astrophysical plasmas. By means of 3D fully kinetic particle-in-cell simulations, we demonstrate that turbulence in low-$\beta$ plasmas ($\beta$ is the…

High Energy Astrophysical Phenomena · Physics 2022-09-16 Luca Comisso , Lorenzo Sironi

We investigate the distribution of particle acceleration sites, independently of the actual acceleration mechanism, during plasmoid-dominated, relativistic collisionless magnetic reconnection by analyzing the results of a particle-in-cell…

High Energy Astrophysical Phenomena · Physics 2015-12-23 Krzysztof Nalewajko , Dmitri A. Uzdensky , Benoît Cerutti , Gregory R. Werner , Mitchell C. Begelman

The early acceleration of protons and electrons in the nonrelativistic collisionless shocks with three obliquities are investigated through 1D particle-in-cell simulations. In the simulations, the charged particles possessing a velocity of…

High Energy Astrophysical Phenomena · Physics 2020-05-06 Jun Fang , Chun-Yan Lu , Jing-Wen Yan , Huan Yu

We use 2D and 3D hybrid (kinetic ions - fluid electrons) simulations to investigate particle acceleration and magnetic field amplification at non-relativistic astrophysical shocks. We show that diffusive shock acceleration operates for…

High Energy Astrophysical Phenomena · Physics 2015-06-17 Damiano Caprioli , Anatoly Spitkovsky

Magnetic reconnection is a plasma phenomenon where a topological rearrangement of magnetic field lines with opposite polarity results in dissipation of magnetic energy into heat, kinetic energy and particle acceleration. Such a phenomenon…

High Energy Astrophysical Phenomena · Physics 2016-08-31 Edoardo Striani , Andrea Mignone , Bhargav Vaidya , Gianluigi Bodo , Attilio Ferrari

Collisionless shock waves, found in supernova remnants, interstellar, stellar, and planetary environments, and laboratories, are one of nature's most powerful particle accelerators. This study combines in situ satellite measurements with…

High Energy Astrophysical Phenomena · Physics 2025-03-05 Savvas Raptis , Ahmad Lalti , Martin Lindberg , Drew L. Turner , Damiano Caprioli , James L. Burch

Direct numerical simulations of turbulent Hall dynamos are presented. The evolution of an initially weak and small scale magnetic field in a system maintained in a stationary turbulent regime by a stirring force at a macroscopic scale is…

Astrophysics · Physics 2009-11-10 P. D. Mininni , D. O. Gómez , S. M. Mahajan

Magnetized turbulence and magnetic reconnection are often invoked to explain the nonthermal emission observed from a wide variety of astrophysical sources. By means of fully-kinetic 2D and 3D PIC simulations, we investigate the interplay…

High Energy Astrophysical Phenomena · Physics 2019-12-04 Luca Comisso , Lorenzo Sironi

Magnetohydrodynamic (MHD) turbulence is an important agent of energetic particle acceleration. Focusing on the compressible properties of magnetic turbulence, we adopt test particle method to study the particle acceleration from Alfv\'en,…

High Energy Astrophysical Phenomena · Physics 2021-12-08 Jianfu Zhang , Fuyuan Xiang

The acceleration of charged particles (electrons and protons) in flaring solar active regions is analyzed by numerical experiments. The acceleration is modelled as a stochastic process taking place by the interaction of the particles with…

Astrophysics · Physics 2009-11-13 A. Anastasiadis , C. Gontikakis , C. Efthymiopoulos

We perform a three-dimensional (3D) global simulation of Earth's magnetosphere with kinetic reconnection physics to study the flux transfer events (FTEs) and dayside magnetic reconnection with the recently developed magnetohydrodynamics…