Internal kinematics of stellar populations in Terzan 5

Globular clusters are stellar systems populated by up to millions of old stars very tightly gravitationally bound. Their absolute ages provide lower limits to the age of the Galactic bulge and the Universe, that can be compared with the one obtained from cosmology. The aim of this project is to study the nearby star cluster Terzan 5 to shed light on some phenomena that occurred in the early universe, like the origin of the Galaxy and the contribution of Globular Clusters to the cosmic reionization. Specifically, I investigated the internal kinematics of multiple stellar populations inTer5 by combining the observed stellar velocities and N-body simulations. I first exploited the computer program KS2 developed at the Space Telescope Science Institute to derive high-precision photometry and proper motions from archive Hubble Space Telescope multi-epoch images of Ter5. The results were used to constrain rotation and construct velocity dispersion distributions of the distinct populations. I then run N-body simulations to reproduce the observed results and infer the kinematic properties of multiple stellar populations. Results try to put some constrain to the formation mechanisms, occurring at high redshift, that are responsible for the formation of Globular Clusters and their role in the assembly of the Galaxy.