On the Mass of the Dark Compact Halo Objects

Abstract

Recently the French EROS collaboration and the American-Australian MACHO collaboration have reported the observation of altogether three possible microlensing events by monitoring over several years the brightness of millions of stars in the Large Magellanic Cloud. For each of these events, assuming they are due to microlensing, we compute the most likely mass for the dark compact halo object, which acted as gravitational lens. The most likely masses are 0.12, 0.31 and 0.38 $M_{\odot}$. The average mass calculated using the method of moments turns out to be 0.14 $M_{\odot}$.