Galactic Archaeology. From multiple stellar populations in star clusters to extremely metal-poor stars

by Dr Giacomo Cordoni (University of Padua)

Thursday 20 Apr 2023, 11:30 → 12:30 Europe/Rome

Sala Jappelli (Osservatorio Astronomico di Padova)

ABSTRACT: 

Galactic archaeology is the study of the history of the nearby universe, with a focus on our own Galaxy. Like classical archaeologists studying fossils to understand the history of humanity, Galactic archaeologists study the most ancient structures observable today, specifically the stellar fossils, to learn about the earliest phases of the Universe. Old Globular Clusters (GCs) and Extremely Metal-Poor stars are among the oldest objects in our Galaxy and offer a unique opportunity to trace the formation of the Milky Way.
Specifically, GCs are known to harbor multiple stellar populations (MPs) with different chemical compositions and possibly ages. However, the origin of these stellar populations remains one of the greatest mysteries of modern stellar astrophysics. Recent theoretical and numerical works suggest that studying the present-day dynamics of stars belonging to different stellar populations provides a unique window into the formation of these objects and sheds light on the Early Universe.
In this context, state-of-the-art astrometry and photometry are combined to explore the internal dynamics of MPs.
Further increasing the complexity of the multi-populations puzzle, recent observations with the Hubble Space Telescope revealed that MPs are not unique to Galactic GCs, but also occur in Galactic Open clusters (OCs) and extra-Galactic clusters younger than 2 Gyr. Remarkably, young and intermediate-age Magellanic Clouds (MC) clusters provide a unique opportunity to study this phenomenon while it is happening or shortly after it occurs.

On a different note, the lowest metallicity stars observable today can yield valuable clues about the formation of the Milky Way. These stars belong to the first generations of stars, and their kinematics can provide crucial information about the events that occurred during the formation of the Milky Way.  

During my presentation, I will analyze various literature and recently obtained findings to offer an overview of the Milky Way's formation process and its associated substructures.

 

Link alla videochiamata: https://meet.google.com/vgc-qjji-ihw
 

Oppure digita: ‪(IT) +39 02 3041 9617‬ PIN: ‪106 964 718‬#