Plasma instabilities and magnetic-field growth in clusters of galaxies

Details Plasma instabilities and magnetic-field growth in clusters of galaxies Plasma instabilities and magnetic-field growth in clusters of galaxies

2005-01-18

arxiv.org/abs/astro-ph/0501362v3

Astrophys.J.629:139-142,2005

Astronomy and Astrophysics

Astrophysics

aastex with emulateapj5; 4 pages; minor corrections to match final published version

Scientific paper

10.1086/431202

We 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.

Affiliated with

Also associated with

No associations

Rating

Plasma instabilities and magnetic-field growth in clusters of galaxies does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Plasma instabilities and magnetic-field growth in clusters of galaxies, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Plasma instabilities and magnetic-field growth in clusters of galaxies will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-704686