OzDES multi-fibre spectroscopy for the Dark Energy Survey: first-year
  operation and results
  OzDES is a five-year, 100-night, spectroscopic survey on the Anglo-Australian
Telescope, whose primary aim is to measure redshifts of approximately 2,500
Type Ia supernovae host galaxies over the redshift range 0.1 < z < 1.2, and
derive reverberation-mapped black hole masses for approximately 500 active
galactic nuclei and quasars over 0.3 < z < 4.5. This treasure trove of data
forms a major part of the spectroscopic follow-up for the Dark Energy Survey
for which we are also targeting cluster galaxies, radio galaxies, strong
lenses, and unidentified transients, as well as measuring luminous red galaxies
and emission line galaxies to help calibrate photometric redshifts.
  Here we present an overview of the OzDES program and our first-year results.
Between Dec 2012 and Dec 2013, we observed over 10,000 objects and measured
more than 6,000 redshifts. Our strategy of retargeting faint objects across
many observing runs has allowed us to measure redshifts for galaxies as faint
as m_r=25 mag. We outline our target selection and observing strategy, quantify
the redshift success rate for different types of targets, and discuss the
implications for our main science goals. Finally, we highlight a few
interesting objects as examples of the fortuitous yet not totally unexpected
discoveries that can come from such a large spectroscopic survey.
