  The boundaries of galaxy groups and clusters are defined by the interplay
between the Newtonian attractive force and the decoupling from the local
expansion of the Universe. This work extends the definition of a zero radial
acceleration surface (ZRAS) and the turnaround surface (TS) for a general
distribution of the masses in an expanding background, governed by the
cosmological constant. We apply these definitions to different galaxy groups in
the local Universe, mapping these groups up to ten megaparsec distances. We
discuss the dipole and the quadrupole rate for the Local Group of Galaxies and
the implementations on the Hubble diagram correction and galaxy groups
virialization. With these definitions, we present the surfaces showing the
interplay between the local expansion vs the local Newtonian attraction for
galaxy groups in the local Universe. Further, we estimate the masses of
different galaxy groups and show that the Cosmological Constant requires these
masses to be higher. For the groups with enough tracers close to the TS, the
contribution of the Cosmological Constant makes the masses to be even higher.
The results show the importance of including the local cosmic expansion in
analyzing the Cosmic Flow of the local Universe.
