Cosmic ray acceleration parameters from multi-wavelength observations. The case of SN 1006

Aims. The properties of the Galactic supernova remnant (SNR) SN 1006 are theoretically reanalysed. Methods. Nonlinear kinetic theory is used to determine the acceleration efficiency of cosmic rays (CRs) in the supernova remnant SN 1006. The known range of astronomical parameters and the existing measurements of nonthermal emission are examined in order to define the values of the relevant physical parameters that determine the CR acceleration efficiency. Results. It is shown that the parameter values - proton injection rate, electron to proton ratio and downstream magnetic field strength - are determined with the appropriate accuracy. In particular the observed azimuthal variations in the gamma-ray morphology also agree with the theoretical expectation. These parameter values, together with the reduction of the gamma-ray flux relative to a spherically symmetric acceleration geometry, allow a good fit to the existing data, including the recently detected TeV emission by H.E.S.S. Conclusions. SN 1006 represents the first example where a high efficiency of nuclear CR production, required for the Galactic CR sources, is consistently established.