Line and Continuum Emission from the Galactic Center. III. Origin of 6.4
  keV Line Emission from Molecular Clouds in the Galactic Center
  We analyze the 6.4 keV line and continuum emission from the molecular cloud
Sgr B2 and the source HESS J1745-303, which is supposed to be a complex of
molecular gas. From the HESS results it follows that Sgr A is a source of high
energy protons, which penetrate into molecular clouds producing there a TeV
gamma-ray flux. We present arguments that Sgr A may also produce a flux of
subrelativistic protons which generate the 6.4 keV line and bremsstrahlung
continuum emission from the clouds.
