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Recent gamma-ray observations show that middle aged supernova remnants (SNRs) interacting with molecular clouds (MCs) can be sources of both GeV and TeV emission. Based on the MC association, two scenarios have been proposed to explain the…

High Energy Astrophysical Phenomena · Physics 2016-09-13 Xiaping Tang , Roger A. Chevalier

In a recent paper (Moskalenko et al., 2002), it has been shown that the flux of secondary cosmic ray (CR) antiprotons appears to be contradictory to measurements of secondary to primary nuclei ratios in cosmic rays when calculated in the…

Astrophysics · Physics 2010-05-27 V. S. Ptuskin , I. V. Moskalenko , F. C. Jones , A. W. Strong , S. G. Mashnik

We develop a formalism for the identification and accurate estimation of the strength of structure formation shocks during cosmological smoothed particle hydrodynamics simulations. Shocks not only play a decisive role for the thermalization…

Astrophysics · Physics 2009-11-11 Christoph Pfrommer , Volker Springel , Torsten A. Ensslin , Martin Jubelgas

Context: Cosmic ray acceleration in galaxy clusters is still an ongoing puzzle, with relativistic electrons forming radio relics at merger shocks and emitting synchrotron radiation. In the present work we perform hybrid-kinetic simulations…

High Energy Astrophysical Phenomena · Physics 2024-02-02 S. S. Boula , J. Niemiec , T. Amano , O. Kobzar

Galaxy clusters form through a sequence of mergers of smaller galaxy clusters and groups. Models of diffusive shock acceleration (DSA) suggest that in shocks that occur during cluster mergers, particles are accelerated to relativistic…

Cosmology and Nongalactic Astrophysics · Physics 2010-10-22 R. J. van Weeren , H. J. A. Rottgering , M. Bruggen , M. Hoeft

Collisionless shock acceleration of protons and C$^{6+}$ ions has been achieved by the interaction of a 10$^{20}$ W/cm$^2$, 1 $\mu$m laser with a near-critical density plasma. Ablation of the initially solid density target by a secondary…

The dissipation of energy from sound waves and weak shocks is one of the most promising mechanisms for coupling AGN activity to the surrounding intracluster medium (ICM), and so offsetting cooling in cluster cores. We present a detailed…

Astrophysics · Physics 2009-11-13 J. Graham , A. C. Fabian , J. S. Sanders

To better model the efficient production of cosmic rays (CRs) in supernova remnants (SNRs) with the associated coupling between CR production and SNR dynamics, we have generalized an existing cr-hydro-NEI code (i.e., Ellison et al. 2012) to…

High Energy Astrophysical Phenomena · Physics 2015-06-04 Shiu-Hang Lee , Donald C. Ellison , Shigehiro Nagataki

Motivated by the suggestion of Kang, Ryu \& Jones (1996) that particles can be accelerated to high energies via diffusive shock acceleration process at the accretion shocks formed by the infalling flow toward the clusters of galaxies, we…

Astrophysics · Physics 2015-06-24 Hyesung Kang , Jörg P. Rachen , Peter L. Biermann

We construct a model for cosmic ray acceleration from protostellar accretion shocks and calculate the resulting cosmic ray ionization rate within star-forming molecular clouds. We couple a protostar cluster model with an analytic accretion…

Astrophysics of Galaxies · Physics 2018-07-25 Brandt A. L. Gaches , Stella S. R. Offner

The acceleration of suprathermal electrons in the solar wind is mainly associated with shocks driven by interplanetary coronal mass ejections (ICMEs). It is well known that the acceleration of electrons is much more efficient at…

Space Physics · Physics 2020-06-17 F. -J. Kong , G. Qin

Collisionless shocks are efficient particle accelerators. At Earth, ions with energies exceeding 100 keV are seen upstream of the bow shock when the magnetic geometry is quasi-parallel, and large-scale supernova remnant shocks can…

High Energy Astrophysical Phenomena · Physics 2016-03-23 Torbjörn Sundberg , Christopher T. Haynes , David Burgess , Christian X. Mazelle

About 1/3 of X-ray-luminous clusters show smooth, unpolarized radio emission on ~Mpc scales, known as giant radio halos. One promising model for radio halos is Fermi-II acceleration of seed relativistic electrons by turbulence of the…

High Energy Astrophysical Phenomena · Physics 2015-03-30 Anders Pinzke , S. Peng Oh , Christoph Pfrommer

When the pressure of particles accelerated at shock waves is no longer negligible compared to the kinetic pressure of the gas, the linear theory of diffusive shock acceleration breaks down. This is expected in particular when the shock…

High Energy Astrophysical Phenomena · Physics 2021-12-22 Thibault Vieu , Stefano Gabici , Vincent Tatischeff

We present results from a Monte Carlo simulation of a parallel collisionless shock undergoing particle acceleration. Our simulation, which contains parameterized scattering and a particular thermal leakage injection model, calculates the…

Space Physics · Physics 2015-06-17 Donald C. Ellison , Donald C. Warren , Andrei M. Bykov

Recent gamma ray observations show that middle aged supernova remnants interacting with molecular clouds can be sources of both GeV and TeV emission. Models involving re-acceleration of pre-existing cosmic rays in the ambient medium and…

High Energy Astrophysical Phenomena · Physics 2015-06-23 Xiaping Tang , Roger A. Chevalier

A numerical study on ion acceleration in electrostatic shock waves is presented, with the aim of determining the best plasma configuration to achieve quasi-monoenergetic ion beams in laser-driven systems. It was recently shown that tailored…

Plasma Physics · Physics 2018-03-14 E. Boella , F. Fiúza , A. Stockem Novo , R. Fonseca , L. O. Silva

Recent precise measurements of cosmic ray (CR) spectra show that the energy distribution of protons is softer than those of heavier nuclei, and there are spectral hardenings for all nuclear compositions above $\sim$200 GV. Models proposed…

High Energy Astrophysical Phenomena · Physics 2017-08-02 Yiran Zhang , Siming Liu , Qiang Yuan

We present a new code aimed at the simulation of diffusive shock acceleration (DSA), and discuss various test cases which demonstrate its ability to study DSA in its full time-dependent and non-linear developments. We present the numerical…

Astrophysics · Physics 2009-11-13 Gilles Ferrand , Turlough Downes , Alexandre Marcowith

The localized deposition of the energy of a laser pulse, as it ablates a solid target, introduces high thermal pressure gradients in the plasma. The thermal expansion of this laser-heated plasma into the ambient medium (ionized residual…

Plasma Physics · Physics 2009-11-30 M E Dieckmann , G Sarri , L Romagnani , I Kourakis , M Borghesi
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