English
Related papers

Related papers: Pre-acceleration in the Electron Foreshock I: Elec…

200 papers

In the Universe matter outside of stars and compact objects is mostly composed of collisionless plasma. The interaction of a supersonic plasma flow with an obstacle results in collisionless shocks that are often associated with intense…

Plasma Physics · Physics 2022-05-18 Artem Bohdan , Martin S. Weidl , Paul J. Morris , Martin Pohl

The non-linear back reaction of accelerated cosmic rays at the shock fronts, leads to the formation of a smooth precursor with a length scale corresponding to the diffusive scale of the energetic particles. Past works claimed that shocklets…

Astrophysics · Physics 2007-08-13 A. Meli , P. L. Biermann , S. Dimitrakoudis

We investigate the physics of quasi-parallel trans-relativistic shocks propagating in weakly magnetized plasmas by means of long-duration two-dimensional particle-in-cell simulations. The structure of the shock precursor is shaped by a…

High Energy Astrophysical Phenomena · Physics 2026-02-09 Taiki Jikei , Daniel Groselj , Lorenzo Sironi

The present paper is the last of a series studying the first-order Fermi acceleration processes at relativistic shock waves with the method of Monte Carlo simulations applied to shocks propagating in realistically modeled turbulent magnetic…

Astrophysics · Physics 2008-11-26 Jacek Niemiec , Michal Ostrowski , Martin Pohl

It is argued and demonstrated by particle-in-cell simulations that the synchrotron maser instability could develop at the front of a relativistic, magnetized shock. The instability generates strong low-frequency electromagnetic waves…

Astrophysics · Physics 2008-11-26 Yuri Lyubarsky

Particle-in-cell (PIC) simulations have shown that relativistic collisionless shocks mediated by the Weibel instability accelerate about 1% of incoming particles, while the majority are transmitted through the shock and become thermalized.…

High Energy Astrophysical Phenomena · Physics 2023-10-20 Jasmine Parsons , Anatoly Spitkovsky , Arno Vanthieghem

We discuss how the electrons in relativistic GRB shocks can reach near-equipartition in energy with the protons. We emphasize the non-Fermi origin of such acceleration. We argue that the dynamics of the electrons in the foreshock region and…

High Energy Astrophysical Phenomena · Physics 2009-06-08 M. V. Medvedev , A. Spitkovsky

Using Magnetospheric Multiscale (MMS) observations at the Earth's quasi-parallel bow shock we demonstrate that electrons are heated by two different mechanisms: a quasi-adiabatic heating process during magnetic field compression,…

Space Physics · Physics 2020-12-09 Krzysztof Stasiewicz , Bengt Eliasson

High Mach number collisionless shocks are found in planetary systems and supernova remnants (SNRs). Electrons are heated at these shocks to the temperature well above the Rankine-Hugoniot prediction. However processes responsible for…

High Energy Astrophysical Phenomena · Physics 2020-11-25 Artem Bohdan , Martin Pohl , Jacek Niemiec , Paul Morris , Yosuke Matsumoto , Takanobu Amano , Masahiro Hoshino

The acceleration of suprathermal electrons in the solar wind is mainly associated with shocks driven by interplanetary coronal mass ejections (ICMEs). It is well known that the acceleration of electrons is much more efficient at…

Space Physics · Physics 2020-06-17 F. -J. Kong , G. Qin

During internal discharge (electrical breakdown by field emission transmission) thin symmetric capacitors accelerate slightly towards the anode; an anomaly that does not appear obvious using standard physics. Various thicknesses of…

Applied Physics · Physics 2019-06-18 Ankur S. Bhatt , F. M. Becker

Electrons in shocks are efficiently energized due to the cross-shock potential, which develops because of differential deflection of electrons and ions by the magnetic field in the shock front. The electron energization is necessarily…

Astrophysics · Physics 2008-11-26 M. Gedalin , M. A. Balikhin , D. Eichler

One-dimensional numerical simulations based on hybrid Eulerian-Lagrangian approach are performed to investigate the interactions between propagating shock waves and dispersed evaporating water droplets in two-phase gas-droplet flows.…

Fluid Dynamics · Physics 2021-02-03 Zhiwei Huang , Huangwei Zhang

Energetic particles spectra at interplanetary shocks often exhibit a power law within a narrow momentum range softening at higher energy. We introduce a transport equation accounting for particle acceleration and escape with diffusion…

High Energy Astrophysical Phenomena · Physics 2021-03-10 Federico Fraschetti

In the present paper we discuss the modifications introduced into the first-order Fermi shock acceleration process due to a finite extent of diffusive regions near the shock or due to boundary conditions leading to an increased particle…

Astrophysics · Physics 2009-10-28 M. Ostrowski , R. Schlickeiser

Shocks in astrophysical transients are key sites of particle acceleration. If the shock upstream is optically thick, radiation smoothens the velocity discontinuity at the shock (radiation-mediated shocks). However, in mildly magnetized…

High Energy Astrophysical Phenomena · Physics 2026-05-12 Shunke Ai , Irene Tamborra

Particle acceleration and heating at mildly relativistic magnetized shocks in electron-ion plasma are investigated with unprecedentedly high-resolution two-dimensional particle-in-cell simulations that include ion-scale shock rippling.…

When the pressure of particles accelerated at shock waves is no longer negligible compared to the kinetic pressure of the gas, the linear theory of diffusive shock acceleration breaks down. This is expected in particular when the shock…

High Energy Astrophysical Phenomena · Physics 2021-12-22 Thibault Vieu , Stefano Gabici , Vincent Tatischeff

Solar flares are known to be prolific electron accelerators, yet identifying the mechanism(s) for such efficient electron acceleration in solar flare (and similar astrophysical settings) presents a major challenge. This is due in part to a…

Solar and Stellar Astrophysics · Physics 2023-04-18 Eduard P. Kontar , A. Gordon Emslie , Galina G. Motorina , Brian R. Dennis

An analytic solution describing an ion-acoustic collisionless shock, self-consistently with the evolution of shock-reflected ions, is obtained. The solution extends the classic soliton solution beyond a critical Mach number, where the…