Osse Results On Galactic Gamma-Ray Line Emission

We report progress in an ongoing search for gamma-ray line emission from the Galaxy using OSSE. Four lines are of interest. The 4.4 and 6.1 MeV lines from de-excitation of C-12 and O-16 excited by cosmic-ray impacts, which were detected by COMPTEL from the Orion molecular cloud, have been searched for st several longitudes in the Galactic plane, without success. Constraints can be placed on one specific model of a point-source origin of the lines. The other two lines, the 1.17 and 1.33 MeV lines from Fe-60, may be present at the limit of OSSE's sensitivity at positive longitudes in the central radian of the Galaxy.