Mapping the stellar age of the Milky Way bulge with the VVV. II. Deep
  JKs catalogs release based on PSF photometry
  The bulge represents the best compromise between old and massive Galactic
component, and as such its study is a valuable opportunity to understand how
the bulk of the Milky Way formed and evolved. In addition, being the only bulge
in which we can individually resolve stars in all evolutionary sequences, the
properties of its stellar content provide crucial insights on the formation of
bulges at large. We aim at providing a detailed and comprehensive census of the
Milky Way bulge stellar populations by producing deep and accurate photometric
catalogs of the inner ~300 sqdeg of the Galaxy. We perform DAOPHOT/ALLFRAME
PSF-fitting photometry of multi-epochs J and Ks images provided by the VVV
survey to obtain deep photometric catalogs. Artificial star experiments have
been conducted on all images to properly assess the completeness and the
accuracy of the photometric measurements. We present a photometric database
containing nearly 600 million stars across the bulge area surveyed by the VVV.
Through the comparison of derived color-magnitude diagrams of selected fields
representative of different levels of extinction and crowding, we show the
quality, completeness and depth of the new catalogs. With the exception of the
fields located along the plane, this new photometry samples stars down to ~1-2
mag below the MS-TO with unprecedented accuracy. To demonstrate the tremendous
potential inherent to this new dataset, we give few examples of possible
applications such as: i) star counts studies through the dataset completeness
map; ii) surface brightness map; and iii) cross-correlation with Gaia DR2. The
database presented here represents an invaluable collection for the whole
community, and we encourage its exploitation. The photometric catalogs
including completeness information are publicly available through the ESO
Science Archive.
