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Galactic dynamics and evolution

The Universe is in motion.  We may not notice as we gaze upon the night sky, but on large timescales galaxies orbit one another and merge with one another.  Astronomers simulate these processes in order to understand them better.


The VINTERGATAN simulation 

Researchers include:  Oscar Agertz, Florent Renaud, Eric Andersson

Spectroscopic surveys of the Milky Way's stars have revealed spatial, chemical and kinematical structures that encode its history. To understand the origins of these trends, we have carried out and dissected a new high resolution cosmological of a Milky Way-like galaxy, VINTERGATAN. (Vintergatan is the Swedish word for Milky Way, literally The Winter Street)

Simulation details and results in:

  • Agertz et al. (2020)VINTERGATAN I: The origins of chemically, kinematically and structurally distinct discs in a simulated Milky Way-mass galaxy
  • Renaud et al. (2020)VINTERGATAN II: the history of the Milky Way told by its mergers
  • Renaud et al. (2020)VINTERGATAN III: how to reset the metallicity of the Milky Way

Dynamical modelling of galaxies 

Researchers include: Paul McMillan, Daniel Mikkola, David Hobbs

Stars orbit in galaxies like the Milky Way under the influence of its gravitational field, which is produced by its stars, gas and dark matter. To understand how these all work together, and how influences like spiral arms alter the orbits, we use sophisticated modelling techniques, including ones based on action-angle coordinates. We use these to understand data from large surveys of the Milky Way, like Gaia and 4MOST.

Some recent publications include:

“Radial migration and vertical action in N-body simulations” - Mikkola, McMillan & Hobbs (2020)
https://ui.adsabs.harvard.edu/abs/2020MNRAS.495.3295M/abstract

“The mass distribution and gravitational potential of the Milky Way” - McMillan (2017)
https://ui.adsabs.harvard.edu/abs/2017MNRAS.465...76M/abstract

Simulated data showing the formation of the Milky Way.
From the VINTERGATAN simulation.