Knot in Centaurus A: A Stochastic Magnetic Field for Diffusive Synchrotron Radiation?

The emission of relativistic electrons moving in the random and small-scale magnetic field is presented by diffusive synchrotron radiation (DSR). In this Letter, we revisit the perturbative treatment of DSR. We propose that a random and small-scale magnetic field might be generated by the turbulence. As an example, multiband radiation of the knot in Cen A comes from the electrons with energy γe ~ 103-104 in the magnetic field of 10-3 G. The multiband spectrum of DSR is well determined by the feature of a stochastic magnetic field. These results put strong constraints on the models of particle acceleration.

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