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Caltech

TAPIR Seminar

Friday, December 6, 2024
2:00pm to 3:00pm
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Online and In-Person Event
The "visible" and "invisible": stars as tracers for the Milky Way formation
Xiaowei Ou, Graduate Student, Dept. of Physics and MIT Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology,

In person: 370 Cahill. To Join via Zoom: 868 5298 8404

ABSTRACT: "How do galaxies form?" is one of the most important questions in modern astrophysics. Hierarchical galaxy formation, the most plausible theory behind galaxy formation, suggests that galaxies, including the Milky Way, grow through the accretion of smaller systems over a scaffolding of an invisible matter called Dark Matter. Such growth is evidenced by the different stellar structures found in the Galaxy over the last few decades, accelerated most recently by the Gaia space mission. Yet, we still lack a full picture of the formation of the Milky Way and its stellar structure, and we are even further in understanding its Dark Matter scaffolding. In this talk, I will present my research on stellar heavy element abundances and kinematic substructures from disrupted dwarf galaxy debris in the Milky Way, probing the galaxies that merged with the Milky Way in the past. Additionally, I will share our work on mapping the dark matter distributions in the Milky Way and one of its ultra-faint dwarf galaxies using stellar dynamics, combining simulations with observational data to study ongoing merger events and how hierarchical assembly shaped the Milky Way today. I will end with an outlook on how synthetic surveys from simulations are helping bridge gaps between theory and observation, offering a path toward a deeper understanding of how the Milky Way came to be.

For more information, please contact JoAnn Boyd by phone at 626-395-4280 or by email at [email protected].