Nonthermal emission of supernova remnant SN 1006 revisited: theoretical
  model and the H.E.S.S. results
  The properties of the Galactic supernova remnant (SNR) SN 1006 are
theoretically re-analyzed in the light of the recent H.E.S.S. results.
Nonlinear kinetic theory is used to determine the momentum spectrum of cosmic
rays (CRs) in space and time in the supernova remnant SN 1006. The physical
parameters of the model - proton injection rate, electron-to-proton ratio and
downstream magnetic field strength - are determined through a fit of the result
to the observed spatially-integrated synchrotron emission properties. The only
remaining unknown astronomical parameter, the circumstellar gas number density,
is determined by a normalization of the amplitude of the gamma-ray flux to the
observed amplitude. The bipolar morphology of both nonthermal X-ray and
gamma-ray emissions is explained by the preferential injection of suprathermal
nuclei and subsequent magnetic field amplification in the quasi-parallel
regions of the outer supernova shock. The above parameters provide an improved
fit to all existing nonthermal emission data, including the TeV emission
spectrum recently detected by H.E.S.S., with the circumstellar hydrogen gas
number density $N_H\approx 0.06 cm^{-3}$ close to values derived from
observations of thermal X-rays. The hadronic and leptonic gamma-ray emissions
are of comparable strength. The overall energy of accelerated CRs at the
present epoch is of the order of 5 % of the total hydrodynamic explosion
energy, and is predicted to rise with time by a factor of $\approx 2$. The
relevance of CR escape from the SNR for the spectrum of the gamma-ray emission
is demonstrated. The sum of the results suggests that SN 1006 is a CR source
with a high efficiency of nuclear CR production, as required for the Galactic
CR sources, both in flux as well as in cutoff energy.
