Relativistic MHD turbulence in hot plasmas and synchrotron polarization properties

Relativistically hot plasmas are well known astrophysical sources of synchrotron emission, and the degree of linear polarization is affected by the level of turbulence in the source. Here we show, by means of a series of 3D numerical simulations, how the properties of decaying turbulence in hot plasmas depend on the magnetization of both the initial guide field and fluctuations, and how the turbulent Kolmogorov-type cascade proceeds in time. Dissipation occurs in thin, intermittent current sheets, variance anysotropy and non-Gaussian deviations appear at small scales. The computed synthetic polarization maps and degree depend on the plasma dynamics and on the angle of the line-of-sight direction with respect to the guide field. We describe how observations of these quantities may be used to infer the turbulence properties in the source.