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Related papers: The Density Spike in Cosmic-Ray-Modified Shocks: F…

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We study the shock structure and the sub-shocks formation in a binary mixture of rarefied polyatomic gases, considering the dissipation only due to the dynamic pressure. We classify the regions depending on the concentration and the Mach…

Fluid Dynamics · Physics 2023-05-19 Tommaso Ruggeri , Shigeru Taniguchi

The acceleration of cosmic rays up to PeV energies at supernova remnant shocks requires an amplification of the ambient magnetic field. The amplification mechanism must operate upstream of the shock, to prevent the escape of particles from…

High Energy Astrophysical Phenomena · Physics 2026-04-21 S. Gabici , J. C. Raymond , A. Ciardi , P. Cristofari , S. Recchia , V. Tatischeff

The properties of cosmic shock waves are studied through numerical simulations in two cosmological scenarios (SCDM and LCDM). The scaling relations for the average radius and velocity associated with the accretion shocks are somewhat…

Astrophysics · Physics 2007-05-23 Francesco Miniati , Dongsu Ryu , Hyesung Kang , T. W. Jones

Recent studies have found that cosmic ray transport plays an important role in feedback processes such as star formation and the launching of galactic winds. Although cosmic ray buoyancy is widely held to be a destabilizing force in…

High Energy Astrophysical Phenomena · Physics 2018-06-27 Evan Heintz , Ellen G. Zweibel

We examine in detail the recent proposal that extreme Cosmic-Ray-Dominated-Regions (CRDRs) characterize the ISM of galaxies during events of high-density star formation, fundamentally altering its initial conditions (Papadopoulos 2010).…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-19 Padeli P. Papadopoulos , Wing-Fai Thi , Francesco Miniati , Serena Viti

The influence of the presence of cosmic fluid on the magnetosonic waves and modulation instabilities in the interstellar medium of spiral galaxies is investigated. The fluid model is developed by modifying the pressure equation in such…

Plasma Physics · Physics 2025-01-08 Jyoti Turi , Gadadhar Banerjee

The cosmic rays non-resonant streaming instability is believed to be the source of substantial magnetic field amplification. In this work we investigate the effects of the ambient plasma temperature on the instability and derive analytical…

High Energy Astrophysical Phenomena · Physics 2020-11-18 Alexis Marret , Andrea Ciardi , Roch Smets , Julien Fuchs

We found that loosely wound spiral shocks in an isothermal gas disk caused by a non-axisymmetric potential are hydrodynamically unstable, if the shocks are strong enough. High resolution, global hydrodynamical simulations using three…

Astrophysics · Physics 2009-11-10 Keiichi Wada , Jin Koda

X-ray shocks and radio relics detected in the cluster outskirts are commonly interpreted as shocks induced by mergers of sub-clumps. We study the properties of merger shocks in merging galaxy clusters, using a set of cosmological…

Cosmology and Nongalactic Astrophysics · Physics 2018-04-25 Ji-Hoon Ha , Dongsu Ryu , Hyesung Kang

We analyse the full shock formation process in electron-ion plasmas in theory and simulations. It is accepted that electromagnetic shocks in initially unmagnetised relativistic plasmas are triggered by the filamentation instability.…

High Energy Astrophysical Phenomena · Physics 2015-06-24 Anne Stockem Novo , Antoine Bret , Ricardo A. Fonseca , Luis O. Silva

Energetic nonthermal particles (cosmic rays, CRs) are accelerated in supernova remnants, relativistic jets and other astrophysical objects. The CR energy density is typically comparable with that of the thermal components and magnetic…

High Energy Astrophysical Phenomena · Physics 2015-06-15 A. M. Bykov , A. Brandenburg , M. A. Malkov , S. M. Osipov

The condition of linear instability for a converging cylindrical shock wave in an arbitrary inviscid medium is obtained. The shape of resulting shock wave front is not changed significantly, but the restriction of energy cumulation can be…

Fluid Dynamics · Physics 2021-10-05 Sergey G. Chefranov

The explosion of massive stars in core-collapse supernovae may be aided by the convective instabilities that develop in their innermost nuclear burning shells. The resulting fluctuations support the explosion by generating additional…

Solar and Stellar Astrophysics · Physics 2020-06-24 Rémi Kazeroni , Ernazar Abdikamalov

Cosmic ray propagation in the Milky Way and other galaxies is largely diffusive, with mean free path determined primarily by pitch angle scattering from hydromagnetic waves with wavelength of order the cosmic ray gyroradius. In the theory…

High Energy Astrophysical Phenomena · Physics 2020-02-19 Ellen G. Zweibel

We perform a three-dimensional nonideal magnetohydrodynamic simulation of a strongly magnetized cloud core and investigate the complex structure caused by the interchange instability. This is the first simulation that does not use a central…

Solar and Stellar Astrophysics · Physics 2025-01-16 Masahiro N. Machida , Shantanu Basu

Observations of large-scale radio emissions prove the existence of shock accelerated cosmic-ray electrons in galaxy clusters, while the lack of detected $\gamma$-rays limits the acceleration of cosmic-ray protons in galaxy clusters. This…

High Energy Astrophysical Phenomena · Physics 2020-04-22 Denis Wittor , Franco Vazza , Dongsu Ryu , Hyesung Kang

Strong astrophysical shocks, diffusively accelerating cosmic rays (CR) ought to develop CR precursors. The length of such precursor $L_{p}$ is believed to be set by the ratio of the CR mean free path $\lambda$ to the shock speed, i.e.,…

High Energy Astrophysical Phenomena · Physics 2011-02-22 M. A. Malkov , P. H. Diamond , R. Z. Sagdeev

We extend the linear analysis of the drag instability in a 1D perpendicular isothermal C-shock by Gu & Chen to 2D perpendicular and oblique C-shocks in the typical environment of star-forming clouds. Simplified dispersion relations are…

Solar and Stellar Astrophysics · Physics 2021-06-21 Pin-Gao Gu

It is presumed that the observed cosmic rays up to about $3\times 10^{18}$ eV are of Galactic origin, the particles being the ones which are found in the composition of the stellar winds of stars that explode as supernova into the…

Astrophysics · Physics 2007-05-23 Adrian Sabin Popescu

The cosmic ray current-driven (CRCD) instability, predicted by Bell (2004), consists of non-resonant, growing plasma waves driven by the electric current of cosmic rays (CRs) that stream along the magnetic field ahead of both relativistic…

Astrophysics · Physics 2011-02-11 Mario A. Riquelme , Anatoly Spitkovsky