Statistical analysis of Galactic globular cluster type properties
  The analysis of pseudo-colour diagrams, the so-called chromosome maps, of
Galactic globular clusters (GCs) permits to classify them into type I and type
II clusters. Type II GCs are characterized by an above-the-average complexity
of their chromosome maps and some of them are known to display star-to-star
variations of slow neutron-capture reaction elements including iron. This is at
the basis of the hypothesis that type II GCs may have an extragalactic origin
and were subsequently accreted by the Milky Way. We performed a Principal
Component Analysis to explore possible correlations among various GCs
parameters in the light of this new classification. The analysis revealed that
cluster type correlates mainly with relative age. The cause of this relation
was further investigated finding that more metal-rich type II clusters, also
appear to be younger and more distant from the Galactic centre. A depletion of
type II clusters for positive values of Galactic coordinate Z was also
observed, with no type II clusters detected above Z$\sim2$ kpc. Type II cluster
orbits also have larger eccentricities than type I ones.
