Weak gravitational lensing as a probe of physical properties of
  substructures in dark matter halos
  We propose a novel method to select satellite galaxies in outer regions of
galaxy groups or clusters using weak gravitational lensing. The method is based
on the theoretical expectation that the tangential shear pattern around
satellite galaxies would appear with negative values at an offset distance from
the center of the main halo. We can thus locate the satellite galaxies
statistically with an offset distance of several lensing smoothing scales by
using the standard reconstruction of surface mass density maps from weak
lensing observation. We test the idea using high-resolution cosmological
simulations. We show that subhalos separated from the center of the host halo
are successfully located even without assuming the position of the center. For
a number of such subhalos, the characteristic mass and offset length can be
also estimated on a statistical basis. We perform a Fisher analysis to show how
well upcoming weak lensing surveys can constrain the mass density profile of
satellite galaxies. In the case of the Large Synoptic Survey Telescope with a
sky coverage of 20,000 square degrees, the mass of the member galaxies in the
outer region of galaxy clusters can be constrained with an accuracy of ~0.1 dex
for galaxy clusters with mass 10^14 Msun/h at z=0.15. Finally we explore the
detectability of tidal stripping features for subhalos having a wide range of
masses of 10^11-10^13 Msun/h.
