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Merger shocks induce turbulence in the intra-cluster medium (ICM), and, under some circumstances, accelerate electrons to relativistic velocities to form so-called radio relics. Relics are mostly found at the periphery of galaxy clusters…

Cosmology and Nongalactic Astrophysics · Physics 2012-10-18 Luigi Iapichino , Marcus Brüggen

Observations of Faraday rotation and synchrotron emission in galaxy clusters imply large-scale magnetic fields with $\mu\mathrm{G}$ strengths possibly extending back to $z=4$. Non-radiative cosmological simulations of galaxy clusters show a…

Galactic cosmic rays (CRs) are accelerated by astrophysical shocks, primarily supernova remnants (SNRs), via diffusive shock acceleration (DSA), an efficient mechanism that predicts power-law energy distributions of CRs. However,…

High Energy Astrophysical Phenomena · Physics 2021-09-24 Rebecca Diesing , Damiano Caprioli

We investigate the appearance of magnetic field amplification resulting from a cosmic ray escape current in the context of supernova remnant shock waves. The current is inversely proportional to the maximum energy of cosmic rays, and is a…

High Energy Astrophysical Phenomena · Physics 2015-06-16 K. M. Schure , A. R. Bell

Strong shocks in collisionless plasmas, such as supernovae shocks and shocks driven by coronal mass ejections, are known to be a primary source of energetic particles. Due to their different mass per charge ratio, the interaction of heavy…

Powerful stellar winds and supernova explosions with intense energy release in the form of strong shock waves can convert a sizeable part of the kinetic energy release into energetic particles. The starforming regions are argued as a…

High Energy Astrophysical Phenomena · Physics 2015-06-12 A. M. Bykov , P. E. Gladilin , S. M. Osipov

Collisionless shocks are common features in space and astrophysical systems where supersonic plasma flows interact, such as in the solar wind, the heliopause, and supernova remnants. Recent experimental capabilities and diagnostics allow…

It is shown that collisionless shock waves can be driven in unmagnetized electron-positron plasmas by performing a two-dimensional particle-in-cell simulation. At the shock transition region, strong magnetic fields are generated by a…

Astrophysics · Physics 2008-03-31 Tsunehiko N. Kato

We present the first numerical model of the magnetohydrodynamical cosmic-ray (CR) driven dynamo of the type proposed by Parker (1992). The driving force of the amplification process comes from CRs injected into the galactic disk in randomly…

Astrophysics · Physics 2009-11-10 M. Hanasz , G. Kowal , K. Otmianowska-Mazur , H. Lesch

The available data on isolated X-ray pulsars, their wind nebulae, and the supernova remnants which are connected to some of these sources are analyzed. It is shown that electric fields of neutron stars tear off charged particles from the…

Astrophysics · Physics 2009-11-13 Sevinc O. Tagieva , Askin Ankay , Arzu M. Ankay

We review the main observational and theoretical facts about acceleration of Galactic cosmic rays in supernova remnants, discussing the arguments in favor and against a connection between cosmic rays and supernova remnants, the so-called…

High Energy Astrophysical Phenomena · Physics 2017-08-23 Pasquale Blasi

Diffusive shock acceleration (DSA) is a prominent mechanism for energizing charged particles up to very large rigidities at astrophysical collisionless shocks. In addition to ions and electrons, it has been proposed that interstellar dust…

High Energy Astrophysical Phenomena · Physics 2024-10-31 P. Cristofari , V. Tatischeff , M. Chabot

The theory of first order Fermi acceleration at shocks assumes that particles diffuse due to scattering off slow-moving magnetic irregularities. However, cosmic rays are closely tied to magnetic field lines, and the transport process,…

Astrophysics · Physics 2011-05-23 P. Duffy , J. G. Kirk , Y. A. Gallant , R. O. Dendy

Cosmic-ray streaming instabilities at supernova shocks are discussed in the quasilinear diffusion formalism which takes into account the feedback effect of wave growth on the cosmic ray streaming motion. In particular, the nonresonant…

High Energy Astrophysical Phenomena · Physics 2015-05-13 Qinghuan Luo , Don Melrose

We investigate the observability, by direct and indirect means, of a shock precursor arising from magnetic field amplification by cosmic rays. We estimate the depth of such a precursor under conditions of nonresonant amplification, which…

High Energy Astrophysical Phenomena · Physics 2015-06-19 J. Martin Laming , Una Hwang , Parviz Ghavamian , Cara Rakowski

Magnetic fields permeate the Universe on all scales and play a key role during star formation. We study the evolution of magnetic fields around a massive metal-free (Population III) star at $z \sim 15$ during the growth of its HII region…

Astrophysics of Galaxies · Physics 2016-08-03 Daegene Koh , John H. Wise

Recent observations of greatly amplified magnetic fields ($\delta B/B\sim 100$) around supernova shocks are consistent with the predictions of the non-linear theory of particle acceleration (NLT), if the field is generated upstream of the…

Astrophysics · Physics 2008-11-26 Damiano Caprioli , Pasquale Blasi , Elena Amato , Mario Vietri

We have calculated the evolution of cosmic ray (CR) modified astrophysical shocks for a wide range of shock Mach numbers and shock speeds through numerical simulations of diffusive shock acceleration (DSA) in 1D quasi- parallel plane…

Astrophysics · Physics 2009-11-10 H. Kang , T. W. Jones

We propose that strong magnetic fields should be generated at shock waves associated with formation of galaxies or clusters of galaxies by the Weibel instability, an instability in collisionless plasmas. The strength of the magnetic fields…

Astrophysics · Physics 2009-11-13 Yutaka Fujita , Tsunehiko N. Kato

We investigate the long-time evolution of magnetic fields generated by the two-stream instability at ultra- and sub-relativistic astrophysical collisionless shocks. Based on 3D PIC simulation results, we introduce a 2D toy model of…

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