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Related papers: Critical Mach Numbers for Magnetohydrodynamic Shoc…

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Shock waves play an important role in turbulent astrophysical media by compressing the gas and dissipating the turbulent energy into the thermal energy. We here study shocks in magnetohydrodynamic turbulence using high-resolution…

High Energy Astrophysical Phenomena · Physics 2019-04-17 Junseong Park , Dongsu Ryu

It is shown that, under some generic assumptions, shocks cannot accelerate particles unless the overall shock Mach number exceeds a critical value M > sqrt(5). The reason is that for M <= sqrt(5) the work done to compress the flow in a…

High Energy Astrophysical Phenomena · Physics 2015-06-16 Jacco Vink , Ryo Yamazaki

We study the stability properties of hydrodynamic shocks with finite Mach numbers. The linear analysis supplements previous analyses which took the strong shock limit. We derive the linearised equations for a general specific heat ratio as…

Astrophysics · Physics 2009-11-13 Babulakshmanan Ramachandran , Michael D. Smith

The acceleration of relativistic particles due to repeated scattering across a shock wave remains the most attractive model for the production of energetic cosmic rays. This process has been analyzed extensively during the past two decades…

Astrophysics · Physics 2009-11-06 Peter A. Becker , Demosthenes Kazanas

Electron acceleration in collisionless shocks with arbitrary magnetic field orientations is discussed. It is shown that the injection of thermal electrons into diffusive shock acceleration process is achieved by an electron beam with a…

High Energy Astrophysical Phenomena · Physics 2010-05-25 Takanobu Amano , Masahiro Hoshino

The formation of unmagnetized electrostatic shock-like structures with a high Mach number is examined with one- and two-dimensional particle-in-cell (PIC) simulations. The structures are generated through the collision of two identical…

Plasma Physics · Physics 2015-06-17 Mark E Dieckmann , Gianluca Sarri , Domenico Doria , Martin Pohl , Marco Borghesi

We investigate the Mach number dependence of the radiative overstability of shocks. We find that the stability of radiative shocks increases with decreasing Mach number, with the result that M=2 shocks require cooling exponents < -1.2 to be…

Astrophysics · Physics 2009-11-11 J. M. Pittard , M. S. Dobson , R. H. Durisen , J. E. Dyson , T. W. Hartquist , J. T. O'Brien

Shocks act to convert incoming supersonic flows to heat, and in collisionless plasmas the shock layer forms on kinetic plasma scales through collective electromagnetic effects. These collisionless shocks have been observed in many space and…

Measurements of the time of arrival of shock waves from explosions can serve as powerful markers of the evolution of the shock front for determining crucial parameters driving the blast. Using standard theoretical tools and a simple ansatz…

Fluid Dynamics · Physics 2022-08-10 Jorge S. Diaz , Sam E. Rigby

Nonrelativistic electrostatic unmagnetized shocks are frequently observed in laboratory plasmas and they are likely to exist in astrophysical plasmas. Their maximum speed, expressed in units of the ion acoustic speed far upstream of the…

Plasma Physics · Physics 2015-06-15 ME Dieckmann , H Ahmed , G Sarri , D Doria , I Kourakis , L Romagnani , M Pohl , M Borghesi

Electron accelerations at high Mach number collision-less shocks are investigated by means of two-dimensional electromagnetic Particle-in-Cell simulations with various Alfven Mach numbers, ion-to-electron mass ratios, and the upstream…

High Energy Astrophysical Phenomena · Physics 2013-11-01 Yosuke Matsumoto , Takanobu Amano , Masahiro Hoshino

Shocks waves are a ubiquitous feature of many astrophysical plasma systems, and an important process for energy dissipation and transfer. The physics of these shock waves are frequently treated/modeled as a collisional, fluid MHD…

Plasma Physics · Physics 2021-11-17 Colby C. Haggerty , Antoine Bret , Damiano Caprioli

Shock waves constitute discontinuities in matter which are relevant in studying the plasma behaviour in astrophysical scenarios and in heavy-ion collision. They can produce conical emission in relativistic collisions and are also thought to…

High Energy Astrophysical Phenomena · Physics 2013-09-03 Ritam Mallick , Stefan Schramm

When two galaxy clusters encounter each other, the interaction results in a collisionless shock that is characterized by a low (1-4) sonic Mach number, and a high Alfv{\'e}nic Mach number. Our goal is to determine if, and to what extent,…

High Energy Astrophysical Phenomena · Physics 2020-06-24 Allard Jan van Marle

This note studies classical magnetohydrodynamic shock waves in an inviscid fluidic plasma that is assumed to be a perfect conductor of heat as well as of electricity. For this mathematically prototypical material, it identifies a critical…

Analysis of PDEs · Mathematics 2015-05-21 Heinrich Freistuhler , Felix Kleber , Johannes Schropp

The character of star formation is intimately related to the supersonic magnetohydrodynamic (MHD) turbulent dynamics of the molecular clouds in which stars form. A significant amount of the turbulent energy dissipates in low velocity…

Astrophysics of Galaxies · Physics 2015-10-09 Andrew Lehmann , Mark Wardle

We explore the physics of shock evolution and particle acceleration in non-relativistic collisionless shocks using multidimensional hybrid simulations. We analyze a wide range of physical parameters relevant to the acceleration of cosmic…

High Energy Astrophysical Phenomena · Physics 2015-05-28 L. Gargaté , A. Spitkovsky

Shock wave refraction at a sharp density interface is a classical problem in hydrodynamics. Presently, we investigate the strongly planar refraction of a magnetohydrodynamic (MHD) shock wave at an inclined density interface. A magnetic…

Fluid Dynamics · Physics 2022-03-14 Fang Chen , Vincent Wheatley , Ravi Samtaney

The dynamics of a shock wave impinging on a transitional high-enthalpy boundary layer out of thermochemical equilibrium is investigated for the first time by means of a direct numerical simulation. The freestream Mach number is equal to 9…

Fluid Dynamics · Physics 2022-12-15 Donatella Passiatore , Luca Sciacovelli , Paola Cinnella , Giuseppe Pascazio

Supersonic outflows from objects as varied as stellar jets, massive stars and novae often exhibit multiple shock waves that overlap one another. When the intersection angle between two shock waves exceeds a critical value, the system…

Instrumentation and Methods for Astrophysics · Physics 2016-06-08 P. Hartigan , J. Foster , A. Frank , E. Hansen , K. Yirak , A. S. Liao , P. Graham , B. Wilde , B. Blue , D. Martinez , P. Rosen , D. Farley , R. Paguio
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