NETWORK SYNTHESIS LOCALIZATION OF 2 SOFT GAMMA REPEATERS

We introduce the method of ''network synthesis,'' which allows the detection of very weak gamma-ray transient signals in the data of the Ulysses gamma-ray burst (GRB) experiment from repeating sources. It consists of defining a grid of alpha, delta values, and for each BATSE detection of a burst from a soft gamma repeater, predicting the arrival time of the burst at Ulysses and co-adding the Ulysses data rephased so that the burst signals are aligned in time and produce a detectable pulse. We demonstrate that this method identifies the position of the soft repeater SGR 1806 - 20, and apply it to the repeater B 1900 + 14. We show that the counterpart to this burst source is probably in or in the vicinity of the Galactic supernova remnant G42.8 + 0.6.