The Accreted Nuclear Clusters of the Milky Way
  A number of the massive clusters in the halo, bulge and disc of the Galaxy
are not genuine globular clusters (GCs), but instead are different beasts
altogether. They are the remnant nuclear star clusters (NSCs) of ancient
galaxies since accreted by the Milky Way. While some clusters are readily
identifiable as NSCs, and can be readily traced back to their host galaxy
(e.g., M54 and the Sagittarius Dwarf galaxy) others have proven more elusive.
Here we combine a number of independent constraints, focusing on their internal
abundances and overall kinematics, to find NSCs accreted by the Galaxy and
trace them to their accretion event. We find that the true NSCs accreted by the
Galaxy are: M54 from the Sagittarius Dwarf, $\omega$ Centari from
Gaia-Enceladus/Sausage, NGC 6273 from Kraken and (potentially) NGC 6934 from
the Helmi Streams. These NSCs are prime candidates for searches of intermediate
mass black holes (BHs) within star clusters, given the common occurrence of
galaxies hosting both NSCs and central massive BHs. No NSC appears to be
associated with Sequoia or other minor accretion events. Other claimed NSCs are
shown not to be such. We also discuss the peculiar case of Terzan 5, which may
represent a unique case of a cluster-cluster merger.
