Plasma instabilities and magnetic-field growth in clusters of galaxies

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dc.creatorSchekochihin, A. A.
dc.creatorCowley, S. C.
dc.creatorKulsrud, R. M.
dc.creatorHammett, G. W.
dc.creatorSharma, P.
dc.date2005-01-18
dc.date2005-08-03
dc.date.accessioned2026-07-07T10:47:58Z
dc.date.available2026-07-07T10:47:58Z
dc.descriptionWe show that under very general conditions, cluster plasmas threaded by weak magnetic fields are subject to very fast growing plasma instabilities driven by the anisotropy of the plasma pressure (viscous stress) with respect to the local direction of the magnetic field. Such an anisotropy will naturally arise in any weakly magnetized plasma that has low collisionality and is subject to stirring. The magnetic field must be sufficiently weak for the instabilities to occur, viz., beta>Re^{1/2}. The instabilities are captured by the extended MHD model with Braginskii viscosity. However, their growth rates are proportional to the wavenumber down to the ion gyroscale, so MHD equations with Braginskii viscosity are not well posed and a fully kinetic treatment is necessary. The instabilities can lead to magnetic fields in clusters being amplified from seed strength of ~10^{-18} G to dynamically important strengths of ~10 microG on cosmologically trivial time scales (~10^8 yr). The fields produced during the amplification stage are at scales much smaller than observed. Predicting the saturated field scale and structure will require a kinetic theory of magnetized cluster turbulence.
dc.descriptionaastex with emulateapj5; 4 pages; minor corrections to match final published version
dc.identifierhttps://arxiv.org/abs/astro-ph/0501362
dc.identifierhttp://arxiv.org/abs/astro-ph/0501362
dc.identifierAstrophys.J.629:139-142,2005
dc.identifierdoi:10.1086/431202
dc.identifier.urihttp://salesiana.dossiersoluciones.com/handle/123456789/183717
dc.subjectAstrophysics
dc.subjectChaotic Dynamics
dc.subjectPlasma Physics
dc.subjectSpace Physics
dc.titlePlasma instabilities and magnetic-field growth in clusters of galaxies
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