연사: Prof. Joss Bland-Hawthorn (University of Sydney)

일시: 2021년 11월 26일 금요일 11:00

장소: 온라인

Abstract:

It is the only galaxy whose formation history can be studied using the full distribution of stars, from white dwarfs to supergiants. The oldest components provide unique insight into how galaxies form and evolve over billions of years. This is a veritable golden age for galactic archaeology with many large surveys now under way to map both chemistry and motions for stars in the Galaxy. Detailed 6D "phase space" information combined with chemistry for millions of stars heralds a new era in how we slice up the Galactic disc. This has already enabled the most remarkable discovery to emerge from ESA's Gaia satellite — the “phase spiral”. This phenomenon, which was not foreseen, is direct evidence of giant waves crossing the disc. We discuss how these Galactic tsunami are generated and what they tell us about our history.