A SEARCH FOR NONBURST EMISSION FROM THE POSITIONS OF WELL-LOCALIZED GAMMA-RAY BURSTS

In this paper, we present the results from the first long-term search for nonburst gamma-ray emission from the positions of 70 intense, well-localized bursts. Using the BATSE occultation technique, designed for monitoring of discrete sources, these burst positions were measured in the energy range of similar to 15 keV-1.8 MeV over a 112 day interval during 1991. None of these 70 locations exhibited detectable emission at or above the level of similar to 5 x 10(-9) ergs cm(-2) s(-1) during the 112 day interval. This level is approximately 1000 times less than the typical intensity of the burst associated with the given location. In addition, 35 intense gamma-ray bursts detected by BATSE were examined in a 5 day interval centered on the time of detection. We find no compelling evidence that these bursts emit preburst emission or display prompt postburst emission at a level of similar to 5 x 10(-9) ergs cm(-2) s(-1) on timescales of similar to 1 hr or longer. The lack of detectable long-term emission or pre- and postburst emission from the positions of gamma-ray bursts has important consequences for a variety of burst production models.