Puzzles of Galactic continuum gamma-rays

Inverse Compton scattering appears to play a more important role in the dif fuse Galactic continuum emission than previously thought, from MeV to GeV e nergies. We compare models having a large inverse Compton component with EG RET data, and find good agreement in the longitude and latitude distributio ns at low and high energies. We test an alternative explanation for the gre ater than or equal to 1 GeV gamma-ray excess, the hard nucleon spectrum, us ing secondary antiprotons and positrons. At lower energies to fit the COMPT EL and OSSE data as diffuse emission requires either a steep upturn in the electron spectrum below 200 MeV or a population of discrete sources.