COS-B Observations of Galactic Gamma-Ray Emission (Large Scale)

Most of the reqions of the sky already observed by COS-B contain part of the galactic disc. Detailed analysis has been completed of the data from many of these observation periods. In several cases a manual scanning, effective in removinq the background events has been incorporated in the processing sequence. The data collected during most of these periods have been merged in order to reveal the structure of the large-scale emission. This large-scale emission features a ridge centered on the galactic equat'or, showing a variable latitude thickness and significant enhancements along the ridqe. While such emission is very bright towards the inner galaxy (320 deg < l < 40 deg) it becomes very weak, and in places not apparent, outside the solar circle. The energy spectra of the large scale emission from selected regions-have been measured. The spectra derived for different longitude bands do not differ, the form of which resembles neither a pure pi-zero nor a power law form.