Title: Testing the formation of extended star clusters through satellite accretion

Abstract:
The recent discoveries of extended star clusters, with size and luminosity comparable to the 
one of faint dwarf galaxies, have progressively blurred the distinction between star clusters and 
dwarf galaxies. It has been suggested that extended clusters formed as compact systems in 
satellite galaxies that later accreted onto the Milky Way. Using N-body simulations, we show 
that a cluster that formed in the tidally-compressive environment provided by the central region 
of a dwarf galaxy satellite undergoes an expansion during the accretion process due to the 
variation of the tidal field. However, the expansion is never enough to produce stellar systems as 
extended as observed, since the resulting clusters are always more compact than the 
corresponding clusters evolved in isolation. We conclude that accretion processes are inefficient 
in explaining the large spatial extent of extended clusters, possibly hinting that these stellar 
systems formed genuinely extended.