Recent achievements on KMHD and applications in the ICM

Abstract

Collisionless plasmas are ubiquitous in the Universe. In general full kinetic equations are needed for a correct description of the physics in such environments. Fluid approximations are, at some special cases, valid. In this work we present the basic equations under such an approximation and the implementation of them in a magnetohydrodynamical code. The numerical simulations are applied for intracluster medium physical properties, i.e. low density but high temperature plasma. We show that, under specific conditions firehose and mirror instabilities may be present. The side effects are the conversion of thermal to magnetic/kinetic energies and the generation of small scale structures ($\sim 1$kpc). We study the changes in the statistics of Faraday rotation measurement, and of the synchrotron polarization, when compared to a standard MHD simulation for the ICM. We conclude that KMHD numerical simulations are mandatory in order to fully understand the statistics of the ICM emission.