Detection of the velocity shear effect on the spatial distributions of
  the galactic satellites in isolated systems
  We report a detection of the effect of the large-scale velocity shear on the
spatial distributions of the galactic satellites around the isolated hosts.
Identifying the isolated galactic systems each of which consists of a single
host galaxy and its satellites from the Seventh Data Release of the Sloan
Digital Sky Survey and reconstructing linearly the velocity shear field in the
local universe, we measure the alignments between the relative positions of the
satellites from their isolated hosts and the principal axes of the local
velocity shear tensors projected on to the plane of sky. We find a clear signal
that the galactic satellites in isolated systems are located preferentially
along the directions of the minor principal axes of the large-scale velocity
shear field. Those galactic satellites which are spirals, brighter, located at
distances larger than the projected virial radii of the hosts and belonging to
the spiral hosts yield stronger alignment signals, which implies that the
alignment strength depends on the formation and accretion epochs of the
galactic satellites. It is also shown that the alignment strength is quite
insensitive to the cosmic web environment as well as the size and luminosity of
the isolated hosts. Although this result is consistent with the numerical
finding of Libeskind et al. based on a N-body experiment, due to the very low
significance of the observed signals it remains inconclusive whether or not the
velocity shear effect on the satellite distribution is truly universal.
