Dissipation in intercluster plasma

Abstract

We discuss dissipative processes in strongly gyrotropic, nearly collisionless plasma in clusters of galaxies (ICM). First, we point out that Braginsky theory, which assumes that collisions are more frequent that the system's dynamical time scale, is inapplicable to fast, sub-viscous ICM motion. Most importantly, the electron contribution to collisional magneto-viscosity dominates over that of ions for short-scale Alfvenic motions. Thus, if a turbulent cascade develops in the ICM and propagates down to scales $\le 1$ kpc, it is damped collisionally not on ions, but on electrons. Second, in high beta plasma of ICM, small variations of the magnetic field strength, of relative value $\sim 1/\beta$, lead to development of anisotropic pressure instabilities (firehose, mirror and cyclotron). Unstable wave modes may provide additional resonant scattering of particles, effectively keeping the plasma in a state of marginal stability. We show that in this case the dissipation rate of a laminar, subsonic, incompressible flows scales as inverse of plasma beta parameter. We discuss application to the problem of ICM heating.

4 pages, accepted by ApJ Lett

References in corpus (7)

• Cluster Magnetic Fields
• Chandra X-ray Observations of the Hydra A Cluster: An Interaction Between the Radio Source and the X-Ray-Emitting Gas
• X-ray Spectroscopy of Cooling Clusters
• The entropy and energy of intergalactic gas in galaxy clusters
• Shearing Box Simulations of the MRI in a Collisionless Plasma
• Regulation of the X-ray luminosity of clusters of galaxies by cooling and supernova feedback
• Turbulence, magnetic fields and plasma physics in clusters of galaxies

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