Not a Copernican observer: biased peculiar velocity statistics in the
  local Universe
  We assess the effect of the local large scale structure on the estimation of
two-point statistics of the observed radial peculiar velocities of galaxies. A
large N-body simulation is used to examine these statistics from the
perspective of random observers as well as "Local Group (LG)-like" observers
conditioned to reside in an environment resembling the observed universe within
20 Mpc. The local environment systematically distorts the shape and amplitude
of velocity statistics with respect to ensemble-averaged measurements made by a
Copernican (random) observer. The Virgo cluster has the most significant
impact, introducing large systematic deviations in all the statistics. For a
simple "top-hat" selection function, an idealized survey extending to $\sim
160h^{-1}\,{\rm Mpc}$ or deeper is needed to completely mitigate the effects of
the local environment. Using shallower catalogues leads to systematic
deviations of the order of $50$ to $200\%$ depending on the scale considered.
For a flat redshift distribution similar to the one of the CosmicFlows-3
survey, the deviations are even more prominent in both the shape and amplitude
at all separations considered $({\stackrel{<}{{}_\sim}} 100h^{-1}\,{\rm Mpc})$.
Conclusions based on statistics calculated without taking into account the
impact of the local environment should be revisited.
