EROS/MACHO GRAVITATIONAL MICROLENSING EVENTS TOWARD LMC IN EVANS HALO MODEL

Abstract

After a decade of gravitational microlensing experiments, 13 to 17 events MACHO group (depending on quality) and two events by EROS have been detected. All of those have been observed in the direction of Large Magellanic Cloud. We use Evans spherically symmetric halo model to study the rate of microlensing events. The expected number of events in this models obtained using EROS and MACHO observational efficiencies. We compare our numbers with the observed events to obtain the fraction of halo that is made by compact objects. It is shown that results derived from the two experiments are in good agreement with each other and MACHOs comprise only a fraction (depending on the model) of Milky Way halo. The results are also compatible with the White Dwarfs population studies in the Hubble Deep Field.