Probing the Bright End of the Rest-Frame Ultraviolet Luminosity Function
  at z = 8-10 with Hubble Pure-Parallel Imaging
  Looking for bright galaxies born in the early universe is fundamental to
investigating the Epoch of Reionization, the era when the first stars and
galaxies ionized the intergalactic medium. We utilize Hubble Space Telescope
pure parallel imaging to select galaxy candidates at a time 500 to 650 million
years after the Big Bang, which corresponds to redshifts z ~ 8-10. These data
come from the Brightest of Reionizing Galaxies Survey (BoRG) Cycle 22 dataset,
which consists of pure-parallel imaging in ~ 90 different lines of sight that
sum up to an area of ~ 420 arcmin^2. This survey uses five filters and has the
advantage (compared to the Cycle 21 BoRG program) of including imaging in the
JH140 band, covering continuous wavelengths from the visible to near-infrared
(lambda = 0.35um - 1.7um). This allows us to perform reliable selection of
galaxies at z>8 using the photometric redshift technique. We use these galaxy
candidates to constrain the bright end of the rest-frame ultraviolet luminosity
function in this epoch. These candidates are excellent targets for follow-up
observations, particularly with the James Webb Space Telescope.
