Globular cluster systems as tracers of environmental effects on Virgo
  early-type dwarfs
  Early-type dwarfs (dEs) are by far the most abundant galaxy population in
nearby clusters. Whether these objects are primordial, or the recent
end-products of the different physical mechanisms that can transform galaxies
once they enter these high-density environments, is still a matter of debate.
Here we present a novel approach to test these scenarios by comparing the
properties of the globular cluster systems (GCSs) of Virgo dEs and their
potential progenitors with simple predictions from gravitational and
hydrodynamical interaction models. We show that low-mass (Mstar < 2E8 Msun) dEs
have GCSs consistent with being the descendants of gas-stripped late-type
dwarfs. On the other hand, higher mass dEs have properties -including the high
mass specific frequencies of their GCSs and their concentrated spatial
distribution within Virgo- incompatible with a recent, environmentally-driven
evolution. They mostly comprise nucleated systems, but also dEs with recent
star formation and/or disc features. Bright, nucleated dEs appear to be a
population that has long resided within the cluster potential well, but have
surprisingly managed to retain very rich and spatially extended GCSs - possibly
an indication of high total masses. Our analysis does not favour violent
evolutionary mechanisms that result in significant stellar mass losses, but
more gentle processes involving gas removal by a combination of internal and
external factors, and highlights the relevant role of initial conditions.
Additionally, we briefly comment on the origin of luminous cluster S0s.
