PHYS/ASTR Colloquium: "Galactic Archaeology via high-resolution spectroscopy of stellar streams" - Dr. Tatyana Sitnova (Institute of Astronomy of the Russian Academy of Sciences)

San Francisco State University

Physics & Astronomy Colloquium Series

Monday, October 9, 2023

3:30 PM, Thornton Hall 411

Dr. Tatyana Sitnova (Institute of Astronomy of the Russian Academy of Sciences)

"Galactic Archaeology via High-resolution Spectroscopy of Stellar Streams"

The Milky Way, with its diverse stellar populations and their chemical composition, is a highly complex object. To understand it, one has to reconstruct all the dynamical and chemical processes that have occurred from its earliest stages to the present day. This area is known as Galactic Archaeology. Using the available to date observational and computational tools, now we can study the ancient history of the Galaxy with an unprecedented accuracy. The Gaia mission has provided parallaxes, proper motions, and radial velocities for 1.5 billion stars. These data enable us to uncover previously unknown galactic substructures, including stellar streams. By combining these findings with high-resolution spectral observations of individual stars, we can investigate the star formation and chemical evolution history in these less massive and more chemically primitive "building blocks" of the Galaxy. In this talk, I will share our recent findings on the chemical abundances in some of the stellar streams. The talk aims to answer the following questions: Why are stellar streams the most suitable objects to study the ancient epoch? and How can we perform the most accurate abundance analysis available to date?