Galactic Archaeology and Stellar Physics
Australian National University (ANU)
Ngunnawal and Ngambri Country
Australian Research Council DECRA Fellow
in Observational Astrophysics at the
Australian National University.
Galactic archaeology addresses three key questions of astrophysics, identified in the current decadal plan of Australian astronomy (2016-2025), through observations of stars as galactic “fossils” in our Milky Way: When, where, and how are stars born? How do galaxies form and evolve? What is the origin of the elements?
Figure: Chemodynamics & chemical cartography of the Milky Way
Different elements of our periodic table are created through different nucleosynthetic channels. Using a clever combination of elemental abundances, I have identified stars that were born outside the Milky Way.
Together with my collaborator Tobias Buck, I study compare predictions of galactic collisions from cosmological simulations with measurements of our Milky Way.
GALAH is a survey that aims to explore the chemical information of stars in our Milky Way. Can we trace back stars that have been born together via their chemical composition? How much did the Galaxy 'self-pollute' itself chemically? How much formation memory is saved or lost? In the framework of Galactic Archaeology we try to address these questions with The GALAH survey.
with 1D/<3D> Non-LTE spectrum synthesis (mainly Spectroscopy Made Easy) & data-driven models (mainly The Cannon)
By comparing the observational patterns (such as those measured by GALAH) and theoretical predictions (such as those made by Kobayashi et al., 2020), we can improve our understanding of which stars and processes create different elements of life.
| Buder et al. (2025d), MNRAS, submitted (arXiv:2510.20233) | The chemodynamical memory of a major merger in a NIHAO-UHD Milky Way analogue II: Were Splash stars heated or already born hot? |
| Buder et al. (2025c), MNRAS, submitted (arXiv:2510.11284) | The chemodynamical memory of a major merger in a NIHAO-UHD Milky Way analogue I: A golden thread through time and space |
| Buder et al. (2025b), PASA, 42, 51 | The GALAH Survey: Data Release 4 |
| Buder et al. (2025a), OJAp, 8, 47 | Local variations of the radial metallicity gradient in a simulated NIHAO-UHD Milky Way analogue and their implications for (extra-)galactic studies |
| Buder et al. (2024), MNRAS, 532, 1010 | Finding accreted stars in the Milky Way: clues from NIHAO simulations |
| Buder et al. (2022), MNRAS, 510, 2407 | The GALAH Survey: chemical tagging and chrono-chemodynamics of accreted halo stars with GALAH+ DR3 and Gaia eDR3 |
| Buder et al. (2021), MNRAS, 506, 150 | The GALAH+ survey: Third data release |
| Buder et al. (2019), A&A, 624, 19 | The GALAH survey: An abundance, age, and kinematic inventory of the solar neighbourhood made with TGAS |
| Buder et al. (2018), MNRAS, 478, 4513 | The GALAH Survey: second data release |
Sven Buder is a Galactic archaeologist and stellar astrophysicist: He uses the light of stars to explore their chemical enrichment. He uses the chemical patterns in combination with the ages, and orbits of stars in our Milky Way to explain its evolution. He got his PhD in 2019 at the Max Planck Institute for Astronomy in Heidelberg for his work on combining stellar orbit information from the Gaia satellite with high-resolution stellar spectra from the Galactic Archaeology with HERMES Survey. As Fellow at the Australian National University, he is leading the GALAH Survey in its second phase to reach 1 million spectra and uses the data to assess how different populations of the Milky Way formed and what impact events like major mergers had on their shape.
A summary of my PhD: the blackboard that I used for my PhD defence.
Social activities and community services have always been part of my live. I like adventures and sports, my life is always balanced by running, cycling or watching sports: I have tried Netball and Touch Football, but you can often find me during parkruns on Saturdays, soccer on Tuesdays and Sundays, and Triathlon training or Bouldering whenever I can (which is sadly increasingly less often).