Description
Data from ESA’s Gaia mission has revolutionised Galactic astronomy, providing an unprecedented view of the Solar neighbourhood and beyond. However, while it provides us a great opportunity to transform our understanding of the Milky Way, it has also highlighted how far from equilibrium our Galaxy is, necessitating the development of simulation and analysis codes which can model and interpret such disequilibrium dynamics.
N-body models naturally capture time-evolving disequilibrium dynamics, but it is not always straightforward to interpret the rich dynamical processes that occur within such models over several Gyr, and across scales from a few pc to 100s of kpc.
Basis function expansion (BFE) allows us to decompose our galaxy simulations (isolated & cosmological) into time series of coefficients which represent the time evolution of the system, and by performing multivariate Singular Spectrum Analysis (mSSA) on said series we can reveal the growth and interaction of underlying dynamical modes in the galaxy. We illustrate the power of BFE & mSSA by revealing and quantifying the interaction of a growing bar and the dark matter halo, including the bar driven dark matter wake in the halo which extends significantly outside the bar region.
