Stars, star clusters, and the central black hole from the Milky Way's Last Major Merger

Abstract: One of the greatest successes of the recently finalized Gaia astrometric space mission was uncovering the Milky Way's most massive accretion events that happened over the last ~10 Gyr, including the Last Major Merger experienced by our Galaxy. The LMC-sized satellite galaxy responsible for this event, dubbed "Gaia-Sausage" or "Gaia-Enceladus" (GSE), brought stars and star clusters that gave rise to the Milky Way's inner halo. Hence, studying the stellar population of GSE provides the opportunity to investigate the formation and evolution of a bright dwarf galaxy with unprecedented detail since its stars are now close enough to be amenable to both detailed dynamics and chemical abundance analysis. I will present the most recent advances in studies of both stars and star clusters from this Last Major Merger. The main topics will be (1) the chemical evolution of heavy elements from the rapid neutron-capture process that occurs in neutron star mergers and (2) the central black hole identified inside the nuclear star cluster of GSE. I will focus on how these discoveries, made possible through a Galactic Archaeology approach, connect with the broad picture of dwarf galaxy evolution.

This seminar is organised by the Ursa Minor research group and is open to all.