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Related papers: Particle acceleration by collisionless shocks cont…

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Questions regarding energy dissipation in astrophysical jets are open to date, despite of numerous attempts to limit the diversity of models. Some of the most popular models assume that energy is transferred to particles via internal…

High Energy Astrophysical Phenomena · Physics 2023-04-24 Patryk Pjanka , Camilia Demidem , Alexandra Veledina

The topic of this review paper is on the influence of solar wind turbulence on shock propagation and its consequence on the acceleration and transport of energetic particles at shocks. As the interplanetary shocks sweep through the…

Solar and Stellar Astrophysics · Physics 2021-02-12 Fan Guo , Joe Giacalone , Lulu Zhao

Diffusion coefficients of energetic charged particles in turbulent magnetic fields are a fundamental aspect of diffusive transport theory but remain incompletely understood. In this work, we use quasi-linear theory to evaluate the spatial…

Solar and Stellar Astrophysics · Physics 2024-03-19 Xiaohang Chen , Joe Giacalone , Fan Guo , Kristopher G. Klein

In solar flares and other astrophysical systems, a major challenge for solving particle acceleration problem associated with magnetic reconnection is the enormous scale separation between kinetic scales and observed reconnection scale.…

Solar and Stellar Astrophysics · Physics 2018-10-08 Xiaocan Li , Fan Guo , Hui Li , Shengtai Li

This proceedings paper reports on the theoretical modelling of particle acceleration in magnetised turbulent plasmas. It briefly reviews some recent findings obtained from fully kinetic numerical simulations of large-amplitude, semi to…

High Energy Astrophysical Phenomena · Physics 2025-12-18 M. Lemoine

Laboratory experiments to explore plasma conditions and stimulated particle acceleration can illuminate aspects of the cosmic particle acceleration process. Here we discuss the cosmic-ray candidate source object variety, and what has been…

High Energy Astrophysical Phenomena · Physics 2009-12-15 Roland Diehl

The Fermi acceleration model was introduced to describe how cosmic ray particles are accelerated to great speeds by interacting with moving magnetic fields. We identify a new variation of the model where light ions interact with a moving…

Plasma Physics · Physics 2022-02-02 J. C. Waybright , M. E. Mlodik , N. J. Fisch

We suggest a physical mechanism whereby the acceleration time of cosmic rays by shock waves can be significantly reduced. This creates the possibility of particle acceleration beyond the knee energy at ~10^15eV. The acceleration results…

Astrophysics · Physics 2009-11-13 M. A. Malkov , P. H. Diamond

We investigate the process of particle acceleration at the termination shock that develops in the bubble excavated by winds of star clusters in the interstellar medium. We develop a theory of diffusive shock acceleration at such shock and…

High Energy Astrophysical Phenomena · Physics 2021-08-05 Giovanni Morlino

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

Observations of large-scale radio emissions prove the existence of shock accelerated cosmic-ray electrons in galaxy clusters, while the lack of detected $\gamma$-rays limits the acceleration of cosmic-ray protons in galaxy clusters. This…

High Energy Astrophysical Phenomena · Physics 2020-04-22 Denis Wittor , Franco Vazza , Dongsu Ryu , Hyesung Kang

Collisionless shock waves are one of the main forms of energy conversion in space plasmas. They can directly or indirectly drive other universal plasma processes such as magnetic reconnection, turbulence, particle acceleration and wave…

The physics of collisionless shocks is a very broad topic which has been studied for more than five decades. However, there are a number of important issues which remain unresolved. The energy repartition amongst particle populations in…

Stationary solutions to the equations of non-linear diffusive shock acceleration play a fundamental role in the theory of cosmic-ray acceleration. Their existence usually requires that a fraction of the accelerated particles be allowed to…

Astrophysics · Physics 2011-02-11 B. Reville , J. G. Kirk , P. Duffy

These notes present the fundamentals of Fermi acceleration at shocks, with a special attention to the role that supernova remnants have in producing Galactic cosmic rays. Then, the recent discoveries in the theory of diffusive shock…

High Energy Astrophysical Phenomena · Physics 2023-10-09 Damiano Caprioli

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

We study relativistic unmagnetized collisionless shocks using unprecedentedly large particle-in-cell simulations of two-dimensional pair plasma. High energy particles accelerated by the shock are found to drive magnetic field evolution on a…

Astrophysics · Physics 2009-06-23 Uri Keshet , Boaz Katz , Anatoly Spitkovsky , Eli Waxman

In this paper we present the first formulation of the theory of non-linear particle acceleration in collisionless shocks in the presence of neutral hydrogen in the acceleration region. The dynamical reaction of the accelerated particles,…

High Energy Astrophysical Phenomena · Physics 2015-06-12 G. Morlino , P. Blasi , R. Bandiera , E. Amato , D. Caprioli

Pulsar winds have been shown to be preferred sites of particle acceleration and high-energy radiation. Numerous studies have been conducted to better characterize the general structure of such relativistic plasmas in isolated systems.…

High Energy Astrophysical Phenomena · Physics 2025-01-06 Valentina Richard-Romei , Benoît Cerutti

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