Speaker
Description
It is now well established that globular clusters (GCs) host multiple stellar populations with distinct chemical compositions. However, the formation mechanisms responsible for the unique abundance patterns observed in these systems remain a major unresolved problem in stellar astrophysics. Although multiple populations are found in the majority of studied old and massive GCs, their incidence and properties vary significantly from cluster to cluster, producing diverse population patterns. This diversity highlights the need for extended and homogeneous surveys of these systems.
Among the key observational signatures of the phenomenon, the spatial distribution of the different populations is particularly important. While the Hubble Space Telescope (HST) has provided detailed information on multiple-population patterns in the cores of ~60 GCs, the outer regions remain poorly explored, with data currently available for less than half of the HST sample.
The VLT Survey Telescope (VST), thanks to its wide field of view, offers a unique opportunity to study multiple populations across the full radial extent of GCs. In this program (ID: 114.27TN, Cycle 3), we observed 47 Galactic GCs using the u, B, and i filters, which are well suited to disentangle chemically distinct stellar populations. By exploiting the VST’s large field of view, this survey enables the first complete and homogeneous mapping of multiple populations across the entire spatial extent of these clusters.