Looking for the Counterparts of $\gamma$-ray Bursts in Catalogues of Astronomical Objects
Session 15 -- Gamma Ray Bursts
Display presentation, Monday, 9, 1995, 9:20am - 6:30pm

## [15.04] Looking for the Counterparts of $\gamma$-ray Bursts in Catalogues of Astronomical Objects

T. E. Harrison, W. R. Webber, B. J. McNamara, A. Lopez (NMSU)

The counterparts of $\gamma$-ray bursts remain elusive. In the twenty five years since their discovery, no compelling candidates have yet been identified. The isotropic distribution of the $\gamma$-ray bursts observed by BATSE suggests that these objects are located at cosmological distances. Deep optical searches of the smallest of these error boxes reveal faint galaxies, and normal-type field stars.

It is now possible to locate $\approx$ 60 $\gamma$-ray bursts to error boxes of 0.25 sq. deg. or smaller. Yet only a handful of these boxes have been optically imaged to search for potential counterparts. We have conducted a survey of a large number of catalogues of both extragalactic and galactic objects to attempt to identify sources which lie within these small error boxes. The catalogues used in our survey were those of normal galaxies, quasars, active galactic nuclei, radio galaxies, galaxy clusters, normal-type stars, and other unusual types of galactic and extragalactic objects. Because of incompleteness, the burst-catalogue matching will never be 100\% successful. To account for this effect, we have used a program that simulates a random distribution of objects to estimate the likelihood that a particular class of catalogued object can be associated with the $\gamma$-ray bursts. We demonstrate that none of the catalogued objects can be conclusively identified as the hosts/sites of the $\gamma$-ray bursts.