BATSE OBSERVATIONS OF GALACTIC POSITRON-ANNIHILATION RADIATION

We are using the Burst And Transient Source Experiment (BATSE) aboard the Compton Gamma-Ray Observatory to study positron annihilation in th e Galaxy. We present upper limits on two bright, transient annihilatio n events reported by the SIGMA telescope aboard the Granat spacecraft. We also present the results of a search for such events from 1E 1740. 7-2942, the Crab, and X-ray nova GRO J0422+32 (Nova Persei) in two yea rs of BATSE data. Finally, we report the first detection of the persis tent galactic Center 511 keV line in BATSE data and discuss the potent ial for mapping studies.