The Bulge Globular Cluster Terzan 6 as seen from Multi-Conjugate Adaptive Optics and the HST

The Galactic Bulge contains about one quarter of the total stellar mass of the Milky Way and represents the oldest massive component of the Galaxy but its formation mechanism, and the one of any galaxy spheroids, remains an extremely debated subject. A detailed characterization of the Bulge globular clusters(GCs) is one of the most promising ways to shed light on this topic. Having ages of 12-13 Gyr, they are direct witnesses of the bulge formation epoch, but also they could be fossil remnants of primordial sub-structures that merged to generate our spheroid (Immeli et al 2004;Carollo et al 2007;Elmegreen et al 2008). Some of them could survive the destruction and be observable as multi-age and multi-Fe GCs, like Terzan5 and Liller1 (Ferraro et al 2009,2021). The master thesis project aims at a detailed characterization of one of the less studied GCs in the Milky Way bulge: Terzan6, in terms of its stellar population(s), structural and dynamical properties, leveraging the advanced capabilities of the multi-conjugated adaptive optics camera GSAOI (GEMINI South Telescope), along with HST. The use of GEMINI NIR filters J,K is essential due to the large interstellar extinction in the Bulge region in the direction of Terzan6, while the optical HST filters are crucial for the construction of a high-resolution reddening map. The combination of the available multi-epoch HST(2016,2021) and GEMINI(2013,2018) observations allowed the determination of relative proper motions to identify the cluster membership, a fundamental step due to the large crowding of the region. The study of the OPT-NIR proper motions selected-, differential reddening corrected-CMD has provided precise estimates of Terzan6's age, distance and the appropriate characterization of the cluster stellar population. Also, the large number of resolved stars has been used to determine the projected density profile of the system and to derive structural parameters and crucial information about its dynamical stage.