Gravitational microlensing by the dark halo of M31

Abstract

It has been shown by Paczyński that gravitational microlensing is potentially a useful method for detecting the dark constituents of the halo of our galaxy, if their mass lies in the approximate domain $10^{-6}<M/M_{\odot }<10^{-1}$. Microlensing observations now im progress monitor several millions of stars in the Large Magellanic Cloud and in the Galactic Bulge. Here I discuss the main features of the microlensing events: in particular their rates and probability.

4, latex, ZU-TH 27/93