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Related papers: The elusive synchrotron precursor of collisionless…

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We investigate the interaction of nonthermal ions (protons and nuclei) accelerated in an ultrarelativistic blastwave with the pre-existing magnetic field of the medium into which the blastwave propagates. While particle acceleration…

Astrophysics · Physics 2009-11-13 Sean M. Couch , Milos Milosavljevic , Ehud Nakar

The extensive observations of the supernova SN 1993J at radio wavelengths make this object a unique target for the study of particle acceleration in a supernova shock. To describe the radio synchrotron emission we use a model that couples a…

High Energy Astrophysical Phenomena · Physics 2015-05-13 Vincent Tatischeff

The expansion of a dense plasma through a more rarefied ionised medium is a phenomenon of interest in various physics environments ranging from astrophysics to high energy density laser- matter laboratory experiments. Here this situation is…

Plasma Physics · Physics 2015-05-19 G. Sarri , I. Kourakis , M. E. Dieckmann , M. Borghesi

In this third paper of a series, we discuss the physics of the population of accelerated particles in the precursor of an unmagnetized, relativistic collisionless pair shock. In particular, we provide a theoretical estimate of their…

High Energy Astrophysical Phenomena · Physics 2019-10-02 Martin Lemoine , Guy Pelletier , Arno Vanthieghem , Laurent Gremillet

Particle acceleration at astrophysical shocks may be very efficient if magnetic scattering is self-generated by the same particles. This nonlinear process adds to the nonlinear modification of the shock due to the dynamical reaction of the…

Astrophysics · Physics 2009-11-11 Elena Amato , Pasquale Blasi

Context. The diffusive shock acceleration mechanism has been widely accepted as the acceleration mechanism for galactic cosmic rays. While self-consistent hybrid simulations have shown how power-law spectra are produced, detailed…

High Energy Astrophysical Phenomena · Physics 2015-06-04 M. Wolff , R. C. Tautz

Intense laser-plasma interactions are an essential tool for the laboratory study of ion acceleration at a collisionless shock. With two-dimensional particle-in-cell calculations of a multicomponent plasma we observe two electrostatic…

The problem of collisionless shocks is posed as the problem of understanding how in a completely collisionless streaming high-temperature plasma shocks can develop at all, forming discontinuous transition layers of thickness much less than…

Astrophysics · Physics 2008-05-15 R. A. Treumann , C. H. Jaroschek

Shock acceleration is an ubiquitous phenomenon in astrophysical plasmas. Plasma waves and their associated instabilities (e.g., the Buneman instability, two-streaming instability, and the Weibel instability) created in the shocks are…

Astrophysics · Physics 2009-11-10 K. -I. Nishikawa , P. Hardee , G. Richardson , R. Preece , H. Sol , G. J. Fishman

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

Plasma instabilities can be encountered in many branches of physics. This work focuses on relativistic plasmas with applications in theoretical astrophysics and particle accelerator physics. Even though these fields seem to be unrelated the…

High Energy Astrophysical Phenomena · Physics 2009-04-20 Bjoern S. Schmekel

Synchrotron emission from astrophysical nonthermal sources usually assumes that the emitting particles are isotropic. By means of large-scale two- and three-dimensional particle-in-cell simulations, we demonstrate that the dissipation of…

High Energy Astrophysical Phenomena · Physics 2020-06-04 Luca Comisso , Emanuele Sobacchi , Lorenzo Sironi

Synchrotron radiation is commonly observed in connection with shocks of different velocities, ranging from relativistic shocks associated with active galactic nuclei, gamma-ray bursts or microquasars to weakly- or non-relativistic flows as…

The formation of collisionless shock fronts is an ubiquitous phenomenon in space plasma environments. In the solar wind shocks might accompany coronal mass ejections, while even more violent events, such as supernovae, produce shock fronts…

High Energy Astrophysical Phenomena · Physics 2020-03-17 Cedric Schreiner , Patrick Kilian , Felix Spanier , Patricio A. Muñoz , Jörg Büchner

Stochastic acceleration of electrons and protons by waves propagating parallel to the large scale magnetic fields of magnetized plasmas is studied with emphasis on the feasibility of accelerating particles from a thermal background to…

Astrophysics · Physics 2016-08-16 Vahé Petrosian , Siming Liu

We investigate the spectrum and polarization of radiation emerging from a subcritical X-ray pulsar using self-consistent radiation-hydrodynamic simulations of an accretion channel in a strong magnetic field. The polarized radiative transfer…

High Energy Astrophysical Phenomena · Physics 2026-05-08 I. D. Markozov , A. Y. Potekhin , A. D. Kaminker , A. A. Mushtukov

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

Relativistic shocks are considered efficient accelerators of charged particles and play crucial roles in high-energy astrophysical phenomena, such as gamma-ray bursts and pulsar winds. This study focuses on positron accelerations in…

High Energy Astrophysical Phenomena · Physics 2026-02-25 Shori Arai , Yosuke Matsumoto

We present a scenario that could explain non-thermal particle acceleration in relativistic quasi-perpendicular electron-positron shocks, such as the termination shock of pulsar wind nebulae. The shock produces a strong electromagnetic…

High Energy Astrophysical Phenomena · Physics 2025-09-10 Emanuele Sobacchi , Yuri Lyubarsky , Lorenzo Sironi , Masanori Iwamoto

Nature's most powerful high-energy sources are capable of accelerating particles to high energy and radiate it away on extremely short timescales, even shorter than the light crossing time of the system. It is yet unclear what physical…

Plasma Physics · Physics 2022-01-03 Luca Comisso , Lorenzo Sironi