Lopsided Satellite Distributions around Isolated Host Galaxies
  We investigate the spatial distribution of the satellites of bright, isolated
host galaxies. In agreement with previous studies, we find that, on average,
the satellites of red hosts are found preferentially close to their hosts'
major axes, while the satellites of blue hosts are distributed isotropically.
We compute the pairwise clustering of the satellites and find a strong tendency
for pairs of satellites to be located on the same side of their host, resulting
in lopsided distributions. The signal is most pronounced for the satellites of
blue hosts, where the number of pairs on the same side of their host exceeds
the number of pairs on opposite sides of their by a factor of 1.8 +/- 0.1. For
the satellites of red hosts, the number of pairs on the same side of their host
exceeds the number of pairs on opposite sides of their host by a factor of 1.08
+/- 0.03. Satellites that are far from their hosts (r_p > 300 kpc) show a
strong preference for being located on the same side of their hosts; satellites
that are near to their hosts (r_p < 100 kpc) show a weak preference for being
located on opposite sides of their hosts. While lopsided distributions have
been found previously for the satellites of bright pairs of galaxies, ours is
the first study to find lopsided distributions for the satellites of isolated
bright galaxies.
