Our Galaxy in its infancy as traced by Gaia and complementary spectroscopic surveys
Paola Di Matteo
Observatoire de Paris
Reconstructing the past of the Milky Way depends on the study of its metal-poor stars, which either have been formed in the Galaxy itself in the first billion years, or have been accreted through mergers of satellite galaxies over time. These stars are usually found in what is known as the Milky Way halo, a light — in terms of total mass — stellar component which is usually made of stars whose kinematics significantly deviates from that of the Galactic disc. In this talk, I will discuss how it has been possible to use the astrometric and spectroscopic data delivered by Gaia and complementary surveys to shed light on the past of our Galaxy, through the study of its halo. Besides the discovery of the possible last significant merger experienced by the Milky Way, the use of 6D phase space information and chemical abundances allowed to reconstruct the impact this merger had on the early Milky Way disc, and the time it occurred, as well as to discover that some of the most metal-poor stars in the Galaxy possibly formed in a disc. This last finding would imply that the dissipative collapse that led to the formation of the old Galactic disc must have been extremely fast.
After a PhD in astronomy at the University La Sapienza in Rome in 2005, during which I studied the formation and evolution of tidal tails around globular clusters by means of N-body models, I moved to France, where I worked as a postdoc in collaboration with Françoise Combes and Matthew Lehnert, on galaxy evolution, focusing in particular on the impact of galaxy mergers in shaping the star formation, morphology and kinematics of galaxies. Since 2011, I am an Astronome Adjoint (Associated Astronomer) at the Paris Observatory. In these last years, I have focused my research mainly on the study of the formation and evolution of the Milky Way and its stellar populations (bulge, disc, halo), coupling the development of N-body models to the analysis of Gaia data, as well as of spectroscopic surveys like APOGEE.
Google Meet (acesso com e-mail USP: https://meet.google.com/pzd-mqvi-maf
Link da transmissão: https://www.youtube.com/c/AstronomiaIAGUSP/live