Radio halo

The linear size of giant radio halos is about 700kpc-1Mpc, whereas mini-halos are typically less than 500kpc.

However, their morphologies typically follow the distribution of gas in the intra-cluster medium.

Mini-halos however, while similar to giant halos, are found at the center of cooling core clusters but around a radio galaxy.

The generated turbulent motions of the intra-cluster plasma drive Magneto-Hydrodynamical Waves, which couples with mildly relativistic particles (i.e. of energy on the level of 100 MeV) and accelerate them up to energy of 10 GeV or more.

They are likely to result from synchrotron radiation originating from electrons accelerated by shock waves, moving in the intracluster magnetic field of around 0.1 - 3 μG.