Orbital and escape dynamics in barred galaxies -- IV. Heteroclinic
  connections
  Continuing the series of papers on a new model for a barred galaxy, we
investigate the heteroclinic connections between the two normally hyperbolic
invariant manifolds sitting over the two index-1 saddle points of the effective
potential. The heteroclinic trajectories and the nearby periodic orbits of
similar shape populate the bar region of the galaxy and a neighbourhood of its
nucleus. Thereby we see a direct relation between the important structures of
the interior region of the galaxy and the projection of the heteroclinic tangle
into the position space. As a side result, we obtain a detailed picture of the
primary heteroclinic intersection surface in the phase space.
