The Super Eight Galaxies: Properties of a Sample of Very Bright Galaxies
  at $7 < z < 8$
  We present the Super Eight galaxies - a set of very luminous, high-redshift
($7.1<z<8.0$) galaxy candidates found in Brightest of Reionizing Galaxies
(BoRG) Survey fields. The original sample includes eight galaxies that are
$Y$-band dropout objects with $H$-band magnitudes of $m_H<25.5$. Four of these
objects were originally reported in Calvi et al. 2016. Combining new Hubble
Space Telescope (HST) WFC3/F814W imaging and $Spitzer$ IRAC data with archival
imaging from BoRG and other surveys, we explore the properties of these
galaxies. Photometric redshift fitting places six of these galaxies in the
redshift range of $7.1<z<8.0$, resulting in three new high-redshift galaxies
and confirming three of the four high-redshift galaxy candidates from Calvi et
al. 2016. We calculate the half-light radii of the Super Eight galaxies using
the HST F160W filter and find that the Super Eight sizes are in line with
typical evolution of size with redshift. The Super Eights have a mean mass of
log(M$_*$/M$_\odot$) $\sim10$, which is typical for sources in this luminosity
range. Finally, we place our sample on the UV $z\sim8$ luminosity function and
find that the Super Eight number density is consistent with other surveys in
this magnitude and redshift range.
