  Recent spectroscopic observations of galaxies in the Fornax-Cluster reveal
nearly unresolved `star-like' objects with red-shifts appropriate to the
Fornax-Cluster. These objects have intrinsic sizes of about 100 pc and absolute
B-band magnitudes in the range -14 < M_B < -11.5 mag and lower limits for the
central surface brightness mu_B >= 23 mag/arcsec^2 (Phillipps et al. 2001,
Hilker et al. 1999), and so appear to constitute a new population of
ultra-compact dwarf galaxies (UCDs). Such compact dwarfs were predicted to form
from the amalgamation of stellar super-clusters (= clusters of star clusters;
not to confuse with super stellar clusters (SSC)) by P. Kroupa (1998), which
are rich aggregates of young massive star clusters (YMCs) that can form in
collisions between gas-rich galaxies. Here we present the evolution of
super-clusters in a tidal field. The YMCs merge on a few super-cluster crossing
times. Super-clusters that are initially as concentrated and massive as Knot S
in the interacting Antennae galaxies (Whitmore et al. 1999) evolve to merger
objects that are long-lived and show properties comparable to the newly
discovered UCDs.
