Emission of SN 1006 produced by accelerated cosmic rays

Abstract

The nonlinear kinetic model of cosmic ray (CR) acceleration in supernova remnants (SNRs) is used to describe the properties of the remnant of SN 1006. It is shown, that the theory fits the existing data in a satisfactory way within a set of parameters which is consistent with the idea that SN 1006 is a typical source of Galactic CR nucleons, although not necessarily of CR electrons. The adjusted parameters are those that are not very well determined by present theory or not directly amenable to astronomical observations. The calculated expansion law and the radio-, X-ray and gamma-ray emissions produced by the accelerated CRs in SN 1006 agree quite well with the observations. A rather large interior magnetic field B_d\approx 100 \muG is required to give a good fit for the radio and X-ray synchrotron emission. In the predicted TeV gamma-ray flux from SN 1006, the pi^0-decay gamma-rays, generated by the nuclear CR component, dominate over the inverse Compton (IC) gamma-rays, generated by the CR electrons in the cosmic microwave background. The predicted source morphology in high energy gamma-rays roughly corresponds to that of the synchrotron emission. The predicted integral gamma-ray flux F \propto e^-1 extends up to energies 100 TeV if CR diffusion is as strong as the Bohm limit. Only if the interior magnetic field is much lower in the SNR, B_d\approx 10 \muG, then the observed gamma-ray emission can be due to the accelerated electron component alone. In this case, not plausible physically in our view, the lowest permissible value of the electron to proton ratio is rather high, and the maximum individual energy and total energy content of accelerated nucleons so small, that SN 1006 can not be considered as a typical source of the nuclear Galactic CRs.