Blanco DECam Bulge Survey (BDBS) II: Project Performance, Data Analysis,
  and Early Science Results
  The Blanco DECam Bulge Survey (BDBS) imaged more than 200 square degrees of
the Southern Galactic bulge using the ugrizY filters of the Dark Energy Camera,
and produced point spread function photometry of approximately 250 million
unique sources. In this paper, we present details regarding the construction
and collation of survey catalogs, and also discuss the adopted calibration and
dereddening procedures. Early science results are presented with a particular
emphasis on the bulge metallicity distribution function and globular clusters.
A key result is the strong correlation (sigma ~ 0.2 dex) between (u-i)o and
[Fe/H] for bulge red clump giants. We utilized this relation to find that
interior bulge fields may be well described by simple closed box enrichment
models, but fields exterior to b ~ -6 degrees seem to require a secondary
metal-poor component. Applying scaled versions of the closed box model to the
outer bulge fields is shown to significantly reduce the strengths of any
additional metal-poor components when compared to Gaussian mixture models.
Additional results include: a confirmation that the u-band splits the sub-giant
branch in M 22 as a function of metallicity, the detection of possible
extra-tidal stars along the orbits of M 22 and FSR 1758, and additional
evidence that NGC 6569 may have a small but discrete He spread, as evidenced by
red clump luminosity variations in the reddest bands. We do not confirm
previous claims that FSR 1758 is part of a larger extended structure.
