Age and metallicity gradients in the Galactic Bulge: A differential study using HST/WFPC2 observations

We test for age and metallicity gradients in the Galactic Bulge between the two low extinction windows Baade's window (l = 1°.1 b = -4°.8) and Sagittarius-I (l = 1°.3 b = -2°.7). We derive a metallicity difference of ≤ 0.2 dex between BW and SGR-I window. This corresponds to a metallicity gradient of 1.3 dex kpc^-1. This steep gradient is reconcilable with the existence of a short scale length inner component to the Bulge, most likely that prominent in the NIR, which perhaps forms a separate entity superimposed on the larger, optical Bulge. Through number counts in colour-magnitude diagram around the turnoff for several fields and clusters, extending over a range in galactic longitude we find no evidence for a significant young stellar population in the Galactic Bulge. Previous suggestions of the existence of a significant young stellar population have most likely incorrectly identified the foreground disk stars.