Subhaloes gone Notts: the clustering properties of subhaloes
  We present a study of the substructure finder dependence of subhalo
clustering in the Aquarius Simulation. We run 11 different subhalo finders on
the haloes of the Aquarius Simulation and we study their differences in the
density profile, mass fraction and 2-point correlation function of subhaloes in
haloes. We also study the mass and vmax dependence of subhalo clustering. As
the Aquarius Simulation has been run at different resolutions, we study the
convergence with higher resolutions. We find that the agreement between finders
is at around the 10% level inside R200 and at intermediate resolutions when a
mass threshold is applied, and better than 5% when vmax is restricted instead
of mass. However, some discrepancies appear in the highest resolution,
underlined by an observed resolution dependence of subhalo clustering. This
dependence is stronger for the smallest subhaloes, which are more clustered in
the highest resolution, due to the detection of subhaloes within subhaloes (the
sub-subhalo term). This effect modifies the mass dependence of clustering in
the highest resolutions. We discuss implications of our results for models of
subhalo clustering and their relation with galaxy clustering.
