Programma: PRIN
Responsabile scientifico per il dipartimento: Alessio Mucciarelli
Struttura principale: DIFA
Data inizio e data fine: dal 28/09/2023 al 28/09/2025
LEGO: archeologia galattica con chimica e dinamica stellare
Il progetto LEGO ricostruisce la storia della Via Lattea combinando spettroscopia, diagnostiche chimiche innovative e dati Gaia, analizzando stelle di campo, ammassi globulari e satelliti galattici.
LEGO: Galactic Archaeology through Stellar Chemistry and Dynamics
LEGO reconstructs the Milky Way’s history by combining spectroscopy, innovative chemical diagnostics, and Gaia data, analyzing field stars, globular clusters, and satellite galaxies.
Abstract
LEGO aims at the full deployment of an innovative approach to study the MW assembly (and more generally the hierarchical processshaping the Local Universe) exploiting the synergy between high-resolution spectroscopy, new chemical diagnostics identified by ourteam and the kinematical information provided by Gaia. More specifically, three categories/samples of stars will be used to draw acoherent and clear picture of the assembly history of the Galaxy and its satellites: (1) Galactic globular clusters (GCs), as tracers ofthe accretion events in the entire Galaxy, (2) Galactic field stars, to get a full chemical tagging of the relics of the Milky Wayformation in the solar neighborhood, where the kinematical and chemical properties of stars can be obtained with unrivaledprecision, (3) field and GC stars in MW satellites that provide a benchmark for the chemical patterns in systems similar to thenow-disrupted building blocks of the MW, while also revealing their own history of assembly within the nearly scale-free process ofhierarchical merging.The feasibility of the approach proposed by LEGO is guaranteed by the success of the new chemical diagnostics that we haveidentified and used (a) to assess the accreted origin of two metal-rich GCs with dynamical properties that made their classificationuncertain, while confirming the in-situ origin of other two metal-rich GCs (Minelli et al. 2021a,b); and (b) to identify among severalGCs in the Large Magellanic Cloud (LMC) a system with a clearly discrepant chemical composition that reveals its external origin in agalaxy that formed stars with a star formation efficiency much lower than that of the LMC. This accreted cluster is the only witness ofa past merger event in the largest MW satellite (Mucciarelli et al. 2021, Nature Astronomy, 5, 1247).LEGO is the kick-off of a new and promising line of research unique in Italy, at the forefront of Galactic Archeology. Should the PRINfunds we apply for be granted, this would be a great opportunity for the Italian astronomical community to play a major role in thisfrontline field of research.