Journal ArticleDOI
An introduction to the theory of diffusive shock acceleration of energetic particles in tenuous plasmas
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In this article, the central idea of diffusive shock acceleration is presented from microscopic and macroscopic viewpoints; applied to reactionless test particles in a steady plane shock, the mechanism is shown to produce a power law spectrum in momentum with a slope which, to lowest order in the ratio of plasma to particle speed, depends only on the compression in the shock.Abstract:
The central idea of diffusive shock acceleration is presented from microscopic and macroscopic viewpoints; applied to reactionless test particles in a steady plane shock the mechanism is shown to produce a power law spectrum in momentum with a slope which, to lowest order in the ratio of plasma to particle speed, depends only on the compression in the shock. The associated time scale is found (also by a macroscopic and a microscopic method) and the problems of spherical shocks, as exemplified by a point explosion and a stellar-wind terminator, are treated by singular perturbation theory. The effect of including the particle reaction is then studied. It is shown that if the scattering is due to resonant waves these can rapidly grow with unknown consequences. The possible steady modified shock structures are classified and generalised Rankine-Hugoniot conditions found. Modifications of the spectrum are discussed on the basis of an exact, if rather artificial, solution, a high-energy asymptotic expansion and a perturbation expansion due to Blandford. It is pointed out that no steady solution can exist for very strong shocks; the possible time dependence is briefly discussed.read more
Citations
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Journal ArticleDOI
Particle acceleration at astrophysical shocks: A theory of cosmic ray origin
TL;DR: In this article, the theory of first order Fermi acceleration at collisionless astrophysical shock fronts is reviewed and it is argued that the wave amplitude is probably non-linear within sufficiently strong astrophysical shocks.
Journal ArticleDOI
Turbulent amplification of magnetic field and diffusive shock acceleration of cosmic rays
TL;DR: In this paper, it was shown that the magnetic field can be amplified from its seed value by orders of magnitude and the consequences for the maximum attainable cosmic ray energy in supernova remnants are explored.
Cosmic rays and particle physics.
TL;DR: In this paper, the authors present a model for accelerating a particle to >100 TeV using cosmic rays and neutrino-induced muons, which they call cosmic ray showers.
Journal ArticleDOI
Short-hard gamma-ray bursts
TL;DR: The theoretical and observational studies of short-hard gamma-ray bursts (SHBs) are reviewed in this article, along with new theoretical results that are presented here for the first time.
Journal ArticleDOI
Nonlinear theory of diffusive acceleration of particles by shock waves
Mikhail Malkov,L. O'c. Drury +1 more
TL;DR: In this article, a review of the current theoretical understanding of this process, from the basic ideas of how a shock energizes a few reactionless particles to the advanced nonlinear approaches treating the shock and accelerated particles as a symbiotic self-organizing system, is presented.
References
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Book
Linear and Nonlinear Waves
TL;DR: In this paper, a general overview of the nonlinear theory of water wave dynamics is presented, including the Wave Equation, the Wave Hierarchies, and the Variational Method of Wave Dispersion.
Journal ArticleDOI
Linear and Nonlinear Waves
G. B. Whitham,T. C. T. Ting +1 more
TL;DR: In this paper, a reference record was created on 2005-11-18, modified on 2016-08-08 and used for the purpose of ondes ; chocs ; onde de : choc reference record.
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The acceleration of cosmic rays in shock fronts – I
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On the Origin of the Cosmic Radiation
TL;DR: In this paper, a theory of the origin of cosmic radiation is proposed according to which cosmic rays are originated and accelerated primarily in the interstellar space of the galaxy by collisions against moving magmetic fields.
Journal ArticleDOI
Particle Acceleration by Astrophysical Shocks
TL;DR: In this article, a new mechanism is proposed for acceleration of a power-law distribution of cosmic rays with approximately the observed slope, where high-energy particles in the vicinity of a shock are scattered by Alfven waves carried by the converging fluid flow leading to a first-order acceleration process in which the escape time is automatically comparable to the acceleration time.