Combining Dark Energy Survey Science Verification Data with Near
  Infrared Data from the ESO VISTA Hemisphere Survey
  We present the combination of optical data from the Science Verification
phase of the Dark Energy Survey (DES) with near infrared data from the ESO
VISTA Hemisphere Survey (VHS). The deep optical detections from DES are used to
extract fluxes and associated errors from the shallower VHS data. Joint 7-band
($grizYJK$) photometric catalogues are produced in a single 3 sq-deg DECam
field centred at 02h26m$-$04d36m where the availability of ancillary
multi-wavelength photometry and spectroscopy allows us to test the data
quality. Dual photometry increases the number of DES galaxies with measured VHS
fluxes by a factor of $\sim$4.5 relative to a simple catalogue level matching
and results in a $\sim$1.5 mag increase in the 80\% completeness limit of the
NIR data. Almost 70\% of DES sources have useful NIR flux measurements in this
initial catalogue. Photometric redshifts are estimated for a subset of galaxies
with spectroscopic redshifts and initial results, although currently limited by
small number statistics, indicate that the VHS data can help reduce the
photometric redshift scatter at both $z<0.5$ and $z>1$. We present example
DES+VHS colour selection criteria for high redshift Luminous Red Galaxies
(LRGs) at $z\sim0.7$ as well as luminous quasars. Using spectroscopic
observations in this field we show that the additional VHS fluxes enable a
cleaner selection of both populations with $<$10\% contamination from galactic
stars in the case of spectroscopically confirmed quasars and $<0.5\%$
contamination from galactic stars in the case of spectroscopically confirmed
LRGs. The combined DES+VHS dataset, which will eventually cover almost 5000
sq-deg, will therefore enable a range of new science and be ideally suited for
target selection for future wide-field spectroscopic surveys.
