Three-Dimensional MHD Simulations of a Subcluster Plasma Moving in Turbulent ICM

High-resolution X-ray observations of clusters of galaxies revealed that hot and cold plasmas coexist in cluster of galaxies. An example is the `cold front' in which temperature decreases from 8 keV to 4 keV in 5 kpc scale, which is a factor of 2-3 smaller than the Coulomb mean free path. Another example is a cold X-ray tail observed in C153 galaxy. These structures indicate that thermal conduction, which smears out the temperature distribution, is suppressed in clusters of galaxies. In our previous study, we carried out 2-D magnetohydrodynamic (MHD) simulations of a moving subclump by including anisotropic heat conduction and showed that large-scale magnetic fields parallel to the front of the moving subclump suppressed the heat conduction across the front. Here we present the results of 3-D MHD simulations assuming turbulent magnetic fields are stretched along the boundary between the cold plasma by the gravity of the subcluster and external hot ICM. These magnetic fields wrapping the subcluster reduce the efficiency of thermal conduction across the magnetic fields and enable the coexistence of hot and cold plasma.