THE GALACTIC HALO MODEL OF GAMMA-RAY BURSTS AND OPTICAL FLASHES FROM THE ANDROMEDA GALAXY

If the classical gamma-ray bursts (GRBs) have their origin in an exten ded Galactic halo, then an analogous population of bursters is expecte d to exist in similar spiral galaxies like our own, in particular in t he Andromeda galaxy. Motivated by the reported non-detection of an exc ess in the number of GRBs seen by BATSE toward M 31 (Fishman 1994), we speculate about an alternative way to detect a possible GRB source po pulation located in the halo of M 31 with the final aim to check the G alactic halo model of GRBs. Having in mind the INTEGRAL mission (Smith et al. 1994), we investigate what is expected to be observable from s uch a hypothetical population of bursters in the halo of M 31 with res pect to their optical flashes which are possibly in general accompanyi ng GRBs as suggested in the literature.