Probing the Small-Scale Angular Distribution of Gamma-Ray Bursts with Combined BATSE/Ulysses 4B Locations

Abstract

We investigate the angular distribution of gamma-ray bursts using the largest catalog of well-localized events that is currently available---combined BATSE/Ulysses burst locations. We present the preliminary spatial analysis of 415 BATSE/Ulysses bursts included in the BATSE 4B catalog. We find that the locations are consistent with large- and small-scale isotropy, with no significant clustering or repetition. We also search for cross-correlation between the BATSE/Ulysses bursts and known extragalactic objects---such as Abell galaxy clusters, radio-quiet QSO, AGN and supernovae---and place limits on the fraction of bursts that could originate from these objects.

LaTeX, 4 pages, 2 figures, Submitted to Proc. of the 3rd INTEGRAL Workshop: The Extreme Universe; Taormina, Italy, Sep. 1998