M. Gennaro Abstract

The IMF and SFH of the Galactic Bulge from HST

M. Gennaro (STScI) , T. M. Brown, J. Anderson, R. Avila, et al.

I will present the latest results from the Hubble Galactic Bulge Treasury Program. The program has targeted 4 different low-extinction windows in the bulge, down to 0.4 solar masses. Imaging was performed in 5 bands, from UV to near-IR, providing excellent coverage of the stellar spectral energy distributions and hence allowing the derivation of stellar masses, metallicities, ages, and extinctions. A second epoch in the I-band enables proper-motion cleaning of foreground stars from the bulge catalogs. To best exploit this unique dataset, I have developed an advanced hierarchical Bayesian technique that uses the information for individual stars to infer the properties of the whole population. I will show the preliminary results on the initial mass function and star-formation history in these 4 bulge fields.