A&a Manuscript No. Diiuse Galactic Gamma-ray Continuum

Coordinated observations of the galactic center region using the imaging SIGMA instrument and the high-sensitivity OSSE instrument were performed to separate the compact source contributions from the diiuse component. The resulting compact-source corrected spectrum of the galactic center region is found to be similar in both intensity and spectral index to the spectra obtained from OSSE observations of the galactic plane at l = 25 and 339 , suggesting that the spatial distribution of the emission is broad and nearly at in galactic longitude. At energies below 100 keV, the observed spectrum is found to be softer and more intense than predicted by theoretical models. The observed low energy continuum may be either diiuse in origin, or due to unresolved X-ray sources below the SIGMA detection threshold.