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Related papers: Generalized Fermi acceleration

200 papers

The acceleration of charged particles in magnetized plasmas is considered during turbulent multi-island magnetic reconnection. The particle acceleration model is constructed for an ensemble of islands which produce adiabatic compression of…

Solar and Stellar Astrophysics · Physics 2015-06-15 Nicolas Bian , Eduard Kontar

Theoretical concepts ofn cosmic ray particle acceleration at relativistic plasma flows -- shocks and shear layers -- are reviewed. We begin with a discussion of mildly relativistic shock waves. The role of oblique field configurations and…

Astrophysics · Physics 2007-05-23 M. Ostrowski

Cosmic ray acceleration through first-order Fermi acceleration in a collisionless plasma relies on efficient scattering off magnetic field fluctuations. Scattering is most efficient for magnetic field fluctuations with wavelengths on the…

High Energy Astrophysical Phenomena · Physics 2015-05-30 K. M. Schure , A. R. Bell

The centrifugal acceleration is due to the rotating poloidal magnetic field in the magnetosphere creates the electric field which is orthogonal to the magnetic field. Charged particles with finite cyclotron radii can move along the electric…

High Energy Astrophysical Phenomena · Physics 2020-01-22 Ya. N. Istomin , A. A. Gunya

Nonlinear, relativistic longitudinal waves with sub-luminal phase velocity $v_p$ are the basis of plasma-based electron accelerators. For such application, key properties of the wave are the maximum or ``wave breaking'' amplitude and the…

Plasma Physics · Physics 2019-07-03 A. Macchi

Charged particles scattering on moving inhomogenities of the magnetised interstellar medium can gain energy through the process of second-order Fermi acceleration. This energy gain depletes in turn the magnetic wave spectrum around the…

High Energy Astrophysical Phenomena · Physics 2020-10-14 M. Kachelriess , J. Tjemsland

We analyse processes of electron acceleration in the Fermi Bubbles in order to define parameters and restrictions of the models, which are suggested for the origin of these giant radio and gamma-ray structures. In the case of leptonic…

Astrophysics of Galaxies · Physics 2015-06-19 K. S. Cheng , D. O. Chernyshov , V. A. Dogiel , C. M. Ko

The non-thermal particle spectra responsible for the emission from many astrophysical systems are thought to originate from shocks via a first order Fermi process otherwise known as diffusive shock acceleration. The same mechanism is also…

High Energy Astrophysical Phenomena · Physics 2015-06-12 B. Reville , A. R. Bell , G. Gregori

Relativistic shocks provide an efficient method for high-energy particle acceleration in many astrophysical sources. Multiple shock systems are even more effective and of importance, for example, in the internal shock model of gamma-ray…

Astrophysics · Physics 2008-11-26 Paul Dempsey , Peter Duffy

We generalize the derivation of electromagnetic fields of a charged particle moving with a constant acceleration [1] to a variable acceleration (piecewise constants) over a small finite time interval using Coulomb's law, relativistic…

Classical Physics · Physics 2018-06-25 Sandeep Aashish , Asrarul Haque

We study stochastic acceleration models for the Fermi bubbles. Turbulence is excited just behind the shock front via Kelvin--Helmholtz, Rayleigh--Taylor, or Richtmyer--Meshkov instabilities, and plasma particles are continuously accelerated…

High Energy Astrophysical Phenomena · Physics 2015-11-10 Kento Sasaki , Katsuaki Asano , Toshio Terasawa

Relativistic particle acceleration in collisionless shocks of supernova remnants is accompanied by magnetic field amplification from cosmic ray (CR) driven plasma instabilities. Bell's fast CR-current instability is predicted to produce…

High Energy Astrophysical Phenomena · Physics 2020-01-08 Sergei M Osipov , Andrei M Bykov , Donald C Ellison

Turbulent magnetic fields are to some extent a universal feature in astrophysical phenomena. Charged particles that encounter these turbulence get on average accelerated according to the so-called second-order Fermi process. However, in…

High Energy Astrophysical Phenomena · Physics 2024-11-25 Dominik Walter , Björn Eichmann

Fermi coordinates are the natural generalization of inertial Cartesian coordinates to accelerated systems and gravitational fields. We study the motion of ultrarelativistic particles and light rays in Fermi coordinates and investigate…

General Relativity and Quantum Cosmology · Physics 2009-11-10 C. Chicone , B. Mashhoon

Nonthermal acceleration of particles in magnetohydrodynamic (MHD) turbulence plays a central role in a wide variety of astrophysical sites. This physics is addressed here in the context of a strong turbulence, composed of coherent…

High Energy Astrophysical Phenomena · Physics 2021-10-06 Martin Lemoine

The process of cosmic ray first-order Fermi acceleration at relativistic shock waves is studied with the method of Monte Carlo simulations. The simulations are based on numerical integration of particle equations of motion in a turbulent…

Astrophysics · Physics 2009-11-10 Jacek Niemiec , Michal Ostrowski

We propose the particle acceleration model coupled with multiple plasmoid ejections in a solar flare. Unsteady reconnection produces plasmoids in a current sheet and ejects them out to the fast shocks, where particles in a plasmoid are…

High Energy Astrophysical Phenomena · Physics 2015-06-12 N. Nishizuka , K. Shibata

In this paper, the acceleration of particles in astrophysical sources by the Fermi mechanism is revisited under the assumption of Lorentz invariance violation (LIV). We calculate the energy spectrum and the acceleration time of particles…

High Energy Astrophysical Phenomena · Physics 2025-07-10 Matheus Duarte , Vitor de Souza

Merger and accretion shocks in clusters of galaxies can accelerate particles via first order Fermi process. Since this mechanism is believed to be intrinsically efficient, shocks are expected to be modified by the backreaction of the…

Astrophysics · Physics 2009-11-10 Stefano Gabici , Pasquale Blasi

It is shown that two circularly polarised Alfv\'en waves that propagate along the ambient magnetic field in an uniform plasma trigger non oscillating electromagnetic field components when they cross each other. The non-oscilliating field…

Earth and Planetary Astrophysics · Physics 2019-02-20 Fabrice Mottez