Star cluster ecology: revisiting the origin of iron and age complex clusters

ABSTRACT Typical globular clusters (GCs – young and old) host stellar populations with little or no star-to-star variations in heavy elements (e.g. Ca, Fe) nor age. Nuclear star (NSCs), on the other hand, complex that show multimodal distributions Fe often age, presumably due to their unique location at centre of a large galactic potential well. However, recently new class have been discovered, exemplified by Terzan 5 Liller 1, two high mass, metallicity inner Galactic regions. It has suggested these are not true GCs, but rather represent left over fragments formation Bulge. Here, we critically assess this scenario find role dynamical friction likely makes it untenable method used estimate initial masses clumps was invalid. Instead, appears more relatively rare phenomenon existing GCs accreting gas forming second generation, as previously suggested.