Statistical Interpretation of LMC Microlensing Candidates

After a decade of gravitational microlensing experiments, a dozen of microlensing candidates towards the LMC stars have been detected by EROS and MACHO groups. Recently it was shown that the distribution of the duration of the observed LMC microlensing events is significantly narrower than what is expected from the standard halo model (Green and Jedamzik 2002). In this article we make the same comparison, using general galactic models (non-standard halo models) and considering the contribution of non-halo components of the Milky Way such as disk, spheroid and LMC itself in the microlensing events. Comparing the theoretical and experimental width of distribution of events duration shows that neither the standard halo model nor the other galactic models have compatibility with the microlensing data at least with 95% of confidence. This results maybe explained if (i) the MACHOs in the galactic halo reside in the clumpy structures or (ii) the events duration have been underestimated due to the blending effect