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Reconnection shocks in a magnetically dominated plasma must be compressive. Non-thermal ion acceleration can occur across built-in slow shocks, and across outflow fast shocks when the outflow is supermagnetosonic and the field is line-tied.…

Astrophysics · Physics 2009-10-22 Eric G. Blackman , George B. Field

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

Electron injection process at high Mach number collisionless quasi-perpendicular shock waves is investigated by means of one-dimensional electromagnetic particle-in-cell simulations. We find that energetic electrons are generated through…

Astrophysics · Physics 2011-02-11 T. Amano , M. Hoshino

We report on the first steady-state simulations of strong plasma shocks with fully kinetic ions and electrons, independently confirmed by two fully kinetic codes (an Eulerian continuum and a Lagrangian particle-in-cell). While kinetic…

The physics of instabilities in the precursor of relativistic collisionless shocks is of broad importance in high energy astrophysics, because these instabilities build up the shock, control the particle acceleration process and generate…

High Energy Astrophysical Phenomena · Physics 2015-06-18 M. Lemoine , G. Pelletier , L. Gremillet , I. Plotnikov

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

The results of hybrid simulation of low-beta supercritical quasi-parallel shocks in high metallicity plasma are presented. The structure of upstream and downstream turbulence is addressed and velocities of the corresponding scattering…

High Energy Astrophysical Phenomena · Physics 2020-01-08 J. A. Kropotina , K. P. Levenfish , A. M. Bykov

Two charge- and current neutral plasma beams are modelled with a one-dimensional PIC simulation. The beams are uniform and unbounded. The relative speed between both beams is 0.4c. One beam is composed of electrons and protons and one out…

Astrophysics · Physics 2014-11-18 M E Dieckmann , A Bret

A two-dimensional electromagnetic particle-in-cell simulation with the realistic ion-to-electron mass ratio of 1836 is carried out to investigate the electrostatic collisionless shocks in relatively high-speed (~3000 km s^-1) plasma flows…

Plasma Physics · Physics 2010-05-12 Tsunehiko N. Kato , Hideaki Takabe

Although the origin of cosmic rays (CRs) remains an open question, collisionless magnetized shock waves are widely regarded as key sites for particle acceleration. Recent theories further suggest that shock-shock collisions in stellar…

Collisionless plasma shock theory, which applies for example to the afterglow of gamma ray bursts, still contains key issues that are poorly understood. In this paper we study charged particle dynamics in a highly relativistic collisionless…

Astrophysics · Physics 2009-11-10 C. B. Hededal , T. Haugboelle , J. Trier Frederiksen , Å. Nordlund

Collisionless shocks, that is shocks mediated by electromagnetic processes, are customary in space physics and in astrophysics. They are to be found in a great variety of objects and environments: magnetospheric and heliospheric shocks,…

We examine with a particle-in-cell (PIC) simulation the collision of two equally dense clouds of cold pair plasma. The clouds interpenetrate until instabilities set in, which heat up the plasma and trigger the formation of a pair of shocks.…

High Energy Astrophysical Phenomena · Physics 2017-03-08 Mark Eric Dieckmann , Antoine Bret

A one-dimensional particle-in-cell (PIC) simulation tracks a fast magnetosonic shock over time scales comparable to an inverse ion gyrofrequency. The magnetic pressure is comparable to the thermal pressure upstream. The shock propagates…

Plasma Physics · Physics 2018-08-01 Q. Moreno , M. E. Dieckmann , X. Ribeyre , E. d'Humières

A full particle simulation study is carried out on the electron acceleration at a collisionless, relatively low Alfven Mach number (M_A=5), perpendicular shock. Recent self-consistent hybrid shock simulations have demonstrated that the…

Astrophysics · Physics 2011-02-11 Takayuki Umeda , Masahiro Yamao , Ryo Yamazaki

A two-dimensional (2D) shock-rest-frame model for particle simulations is developed. Then full kinetic dynamics of a perpendicular collisionless shock is examined by means of a 2D full particle simulation. We found that in the 2D simulation…

Astrophysics · Physics 2009-11-13 Takayuki Umeda , Masahiro Yamao , Ryo Yamazaki

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

A leading explanation for the origin of Galactic cosmic rays is acceleration at high-Mach number shock waves in the collisionless plasma surrounding young supernova remnants. Evidence for this is provided by multi-wavelength non-thermal…

High Energy Astrophysical Phenomena · Physics 2017-08-02 A. Masters , A. H. Sulaiman , Ł. Stawarz , B. Reville , N. Sergis , M. Fujimoto , D. Burgess , A. J. Coates , M. K. Dougherty

While the front of a fluid shock is a few mean-free-paths thick, the front of a collisionless shock can be orders of magnitude thinner. By bridging between a collisional and a collisionless formalism, we assess the transition between these…

Plasma Physics · Physics 2021-07-01 Antoine Bret , Asaf Pe'er

A two-dimensional particle-in-cell simulation is performed to investigate weakly magnetized perpendicular shocks with a magnetization parameter of 6 x 10^-5, which is equivalent to a high Alfv\'en Mach number M_A of ~130. It is shown that…

High Energy Astrophysical Phenomena · Physics 2010-09-03 Tsunehiko N. Kato , Hideaki Takabe