COS-B gamma-ray sources and interstellar gas

Of the gamma-radiation observed above 100 MeV only a few percent is due to the catalogued sources which are viewed against intense background mission from the Galactic plane. There has been considerable recent success in modelling the Galactic plane emission as the interactions of cosmic rays with atomic and molecular interstellar gas; Bloemen, et al., demonstrate that large angular scale features of the observations are well reproduced in this way. By extending the analysis to small angular scales, which of the eCG sources might be due to conventional levels of cosmic rays within clumps of gas are shown and which cannot be so explained. With the use of a more sophisticated model the results presented improve and extend those of an earlier report. So far only the data above 300 MeV is used where the instrument's angular resolution is at its best.