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Injection process of pickup ion acceleration at a heliospheric termination shock is investigated. Using two-dimensional fully kinetic particle-in-cell simulation, accelerated pickup ions are self-consistently reproduced by tracking long…

Plasma Physics · Physics 2024-11-15 S. Matsukiyo , Y. Matsumoto

When supersonic plasma flows collide, many physical processes contribute to the morphology of the resulting shock. One of these processes is the acceleration of non-thermal ions, which will, eventually, reach relativistic speeds and become…

High Energy Astrophysical Phenomena · Physics 2025-09-16 Allard Jan van Marle

We report on the temporally and spatially resolved detection of the precursory stages that lead to the formation of an unmagnetized, supercritical collision-less shock in a laser-driven laboratory experiment. The measured evolution of the…

High Energy Astrophysical Phenomena · Physics 2015-06-15 H Ahmed , ME Dieckmann , L Romagnani , D Doria , G Sarri , M Cherchez , E Ianni , I Kourakis , AL Giesecke , M Notley , R Prasad , K Quinn , O Willi , M Borghesi

We study the pickup ion dynamics and mechanism of multiple reflection and acceleration at the structured quasi-perpendicular supercritical shock. The motion of the pickup ions in the shock is studied analytically and numerically using the…

Space Physics · Physics 2009-10-30 D. Zilbersher , M. Gedalin

Collisionless plasma shocks are efficient sources of non-thermal particle acceleration in space and astrophysical systems. We use hybrid (kinetic ions -- fluid electrons) simulations to examine the non-linear feedback of the self-generated…

High Energy Astrophysical Phenomena · Physics 2020-12-16 Colby C. Haggerty , Damiano Caprioli

Collisionless shocks are efficient particle accelerators. At Earth, ions with energies exceeding 100 keV are seen upstream of the bow shock when the magnetic geometry is quasi-parallel, and large-scale supernova remnant shocks can…

High Energy Astrophysical Phenomena · Physics 2016-03-23 Torbjörn Sundberg , Christopher T. Haynes , David Burgess , Christian X. Mazelle

We use kinetic hybrid simulations (kinetic ions - fluid electrons) to characterize the fraction of ions that are accelerated to non-thermal energies at non-relativistic collisionless shocks. We investigate the properties of the shock…

High Energy Astrophysical Phenomena · Physics 2015-06-23 Damiano Caprioli , Ana-Roxana Pop , Anatoly Spitkovsky

Supernova remnant (SNR) blast shells can reach the flow speed $v_s = 0.1 c$ and shocks form at its front. Instabilities driven by shock-reflected ion beams heat the plasma in the foreshock, which may inject particles into diffusive…

Astrophysics · Physics 2017-08-02 M. E. Dieckmann , A. Meli , P. K. Shukla , L. O. C. Drury , A. Mastichiadis

The growth and saturation of Buneman-type instabilities is examined with a particle-in-cell (PIC) simulation for parameters that are representative for the foreshock region of fast supernova remnant (SNR) shocks. A dense ion beam and the…

Solar and Stellar Astrophysics · Physics 2015-06-05 M. E. Dieckmann , A. Bret , G. Sarri , E. Perez Alvaro , I. Kourakis , M. Borghesi

Colliding collisionless shocks appear in a great variety of astrophysical phenomena and are thought to be possible sources of particle acceleration in the Universe. We have previously investigated particle acceleration induced by single…

We present the particle-in-cell (PIC) simulation results of the interaction of a high-energy lepton plasma flow with background electron-proton plasma and focus on the acceleration processes of the protons. It is found that the acceleration…

High Energy Astrophysical Phenomena · Physics 2015-12-17 Yun-Qian Cui , Zheng-Ming Sheng , Quan-Ming Lu , Yu-Tong Li , Jie Zhang

This review aims at providing an up-to-date status and a general introduction to the subject of the numerical study of energetic particle acceleration and transport in turbulent astrophysical flows. The subject is also complemented by a…

High Energy Astrophysical Phenomena · Physics 2020-02-26 A. Marcowith , G. Ferrand , M. Grech , Z. Meliani , I. Plotnikov , R. Walder

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

Collisionless shocks are common in astrophysical systems and stand as sites of particle acceleration. While particles at perpendicular shocks may not return to the upstream region, at oblique shocks a fraction of energetic electrons manage…

Supernova remnants (SNRs) are believed to produce the majority of galactic cosmic rays (CRs). SNRs harbor non-relativistic collisionless shocks responsible for acceleration of CRs via diffusive shock acceleration (DSA), in which particles…

High Energy Astrophysical Phenomena · Physics 2022-12-20 Artem Bohdan

Electron acceleration in high Mach number perpendicular shocks is investigated through two-dimensional electrostatic particle-in-cell (PIC) simulation. We simulate the shock foot region by modeling particles that consist of three components…

Astrophysics · Physics 2009-11-13 Yutaka Ohira , Fumio Takahara

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…

We perform particle-in-cell simulations of perpendicular nonrelativistic collisionless shocks to study electron heating and pre-acceleration for parameters that permit extrapolation to the conditions at young supernova remnants. Our…

High Energy Astrophysical Phenomena · Physics 2017-10-04 Artem Bohdan , Jacek Niemiec , Oleh Kobzar , Martin Pohl

The acceleration of charged particles at astrophysical collisionless shock waves is one of the best studied processes for the energization of particles to ultrarelativistic energies, required by multifrequency observations in a variety of…

Astrophysics · Physics 2009-11-10 Pasquale Blasi

The last ten years a number of observational advances have substantially increased our knowledge of shock phenomena in supernova remnants. This progress has mainly been made possible by the recent improvements in X-ray and Gamma-ray…

Astrophysics · Physics 2009-11-07 Jacco Vink