Helical Randomization of Magnetized Galaxy Clusters Plasmas Observed in Faraday Rotation Sky

Abstract

Using results of numerical simulations and galaxy clusters observations, it is shown that the transition from deterministic chaos to hard turbulence in the galaxy clusters magnetized plasmas occurs via a randomization process. The notion of distributed chaos has been used to describe the randomization process. The randomization can be quantified with the main parameter of the distributed chaos, which in turn can be related to magnetic helicity. Spontaneous breaking of local reflectional symmetry (an intrinsic property of chaotic/turbulent motions) generates local helicity even when the global helicity is negligible. It is shown that the magnetic fields can impose their level of randomization on the Faraday rotation maps. Results of the numerical simulations of the galaxy clusters dynamos are in good agreement with this approach, as well as with the results obtained using observations of the Faraday rotation sky.