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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

Strong non-relativistic shocks are known to accelerate particles up to relativistic energies. However, for Diffusive Shock Acceleration electrons must have a highly suprathermal energy, implying a need for very efficient pre-acceleration.…

Plasma Physics · Physics 2023-10-24 Karol Fulat , Artem Bohdan , Gabriel Torralba Paz , Martin Pohl

Electron acceleration to non-thermal energies in low Mach number (M<5) shocks is revealed by radio and X-ray observations of galaxy clusters and solar flares, but the electron acceleration mechanism remains poorly understood. Diffusive…

High Energy Astrophysical Phenomena · Physics 2014-10-14 Xinyi Guo , Lorenzo Sironi , Ramesh Narayan

We present a survey of 1D kinetic particle-in-cell simulations of quasi-parallel non-relativistic shocks to identify the environments favorable for electron acceleration. We explore an unprecedented range of shock speeds $v_{\rm sh}\approx…

High Energy Astrophysical Phenomena · Physics 2024-08-30 Siddhartha Gupta , Damiano Caprioli , Anatoly Spitkovsky

Plasma processes close to SNR shocks result in the amplification of magnetic fields and in the acceleration of electrons, injecting them into the diffusive acceleration mechanism. The acceleration of electrons and the B field amplification…

High Energy Astrophysical Phenomena · Physics 2015-06-09 M E Dieckmann , G Murphy , A Meli , L O C Drury

Nonrelativistic electrostatic unmagnetized shocks are frequently observed in laboratory plasmas and they are likely to exist in astrophysical plasmas. Their maximum speed, expressed in units of the ion acoustic speed far upstream of the…

Plasma Physics · Physics 2015-06-15 ME Dieckmann , H Ahmed , G Sarri , D Doria , I Kourakis , L Romagnani , M Pohl , M Borghesi

We explore the physics of shock evolution and particle acceleration in non-relativistic collisionless shocks using multidimensional hybrid simulations. We analyze a wide range of physical parameters relevant to the acceleration of cosmic…

High Energy Astrophysical Phenomena · Physics 2015-05-28 L. Gargaté , A. Spitkovsky

A full particle simulation study is carried out for studying microinstabilities generated at the shock front of perpendicular collisionless shocks. The structure and dynamics of shock waves are determined by Alfven Mach number and plasma…

Plasma Physics · Physics 2015-06-04 Takayuki Umeda , Yoshitaka Kidani , Shuichi Matsukiyo , Ryo Yamazaki

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

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

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

The non-thermal acceleration of electrons and ions at an oblique, non-relativistic shock is studied using large scale particle-in-cell (PIC) simulations in one spatial dimension. Physical parameters are selected to highlight the role of…

Plasma Physics · Physics 2021-11-01 Naveen Kumar , Brian Reville

Electron acceleration to non-thermal, ultra-relativistic energies (~ 10-100 TeV) is revealed by radio and X-ray observations of shocks in young supernova remnants (SNRs). The diffusive shock acceleration (DSA) mechanism is usually invoked…

High Energy Astrophysical Phenomena · Physics 2015-05-20 Mario A. Riquelme , Anatoly Spitkovsky

Electron acceleration associated with various plasma kinetic instabilities in a nonrelativistic, very-high-Alfv\'en Mach-number ($M_A \sim 45$) shock is revealed by means of a two-dimensional fully kinetic PIC simulation. Electromagnetic…

High Energy Astrophysical Phenomena · Physics 2015-06-17 Y. Matsumoto , T. Amano , M. Hoshino

Prescriptions for electron injection into the diffusive shock acceleration process are required in many practical considerations of cosmic-ray astrophysics, particularly in modeling of the synchrotron emission of astrophysical sources. In…

High Energy Astrophysical Phenomena · Physics 2021-01-01 Bojan Arbutina , Vladimir Zeković

Electron acceleration to non-thermal energies is known to occur in low Mach number (M<5) shocks in galaxy clusters and solar flares, but the electron acceleration mechanism remains poorly understood. Using two-dimensional (2D)…

High Energy Astrophysical Phenomena · Physics 2014-11-26 Xinyi Guo , Lorenzo Sironi , Ramesh Narayan

Shock drift acceleration plays an important role in generating high-energy electrons at quasi-perpendicular shocks, but its efficiency in low beta plasmas is questionable. In this article, we perform a two-dimensional particle-in-cell…

Space Physics · Physics 2024-09-06 Ao Guo , Quanming Lu , San Lu , Zhongwei Yang , Xinliang Gao

Energy dissipation in collisionless shocks is a key mechanism in various astrophysical environments. Its non-linear nature complicates analytical understanding and necessitate Particle-in-Cell (PIC) simulations. This study examines the…

High Energy Astrophysical Phenomena · Physics 2024-12-20 Mohamad Shalaby

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

We herein investigate shock formation and particle acceleration processes for both protons and electrons in a quasi-parallel high-Mach-number collisionless shock through a long-term, large-scale particle-in-cell simulation. We show that…

High Energy Astrophysical Phenomena · Physics 2015-06-22 Tsunehiko N. Kato
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