  The possibility that quasi-equilibrium self-gravitating galaxy-like
configurations exist in a tidal field is analyzed in this paper. More
specifically, we address the question of how to predict initial configurations
modeling galaxies that are able to survive environmental effects in a dense
environment for a Hubble time or so, provided thay dynamical friction is
neglected. The initial quasi-equilibrium configurations have been built up
taking into account the external tidal field produced by the halo. It modifies
the escape velocity field of the configuration, compared with isolated
configurations. The survival of the configurations as they orbit inside the
halos has been studied through N-body simulations. As a general result, it has
been found out that the bulk of the models is conserved along 12.5 Gyears of
evolution, and that the low rates of mass losses they experience are consistent
with those expected when the adiabatic protection hypothesis is at work. So,
solutions for galaxy configurations in tidal quasi-equilibrium have been found,
showing that tidal stripping in quiescent phases does not seem to be very
important, unless that the density of the galaxy environment at its formation
had been much lower than that of the galaxy environment at the point of its
orbit where the tidal perturbation is maximum. (Abridged)
