The large microlensing optical depth inferred from the OGLE and MACHO surveys towards the Galactic bulge appears to be inconsistent with the standard model of the Galaxy. The two present solutions, a massive disc or a bar aligned long the line of sight, are not particularly attractive since they are inconsistent with many observations. Here we report detailed, state-of-the-art PM+SPH simulations of the bulge+disc+halo with dark particles, stars and gas components which were fitted to a variety of observables. These are the first models which are consistent with both DIRBE photometry and the kinematic data available for an homogeneous sample of OH/IR stars. We find that their microlensing properties cannot account for the large optical depth observed towards the Bulge by at least a factor two.
Variables Stars and the Astrophysical Returns of the Microlensing Surveys
- Pub Date:
- GALAXY: STRUCTURE;
- DARK MATTER;
- OH/IR STARS;