Institution(s): 1. Lund University
I’ll discuss advances in dynamical modelling over recent years. I’ll talk about what we’ve learned about our place in the Galaxy, and about Galactic structure. A key element in our increased understanding has been innovations in dynamical modelling using “action-angle coordinates”. Distribution functions that depend on actions are in equilibrium in a given potential. They therefore provide us with a method for determining the gravitational field (and thus dark matter density) of the Milky Way. The past few years have produced huge advances in methods that can determine action coordinates in Galactic potentials, and exploit them for modelling.
I will also emphasise that when fitting a dynamical model, it is not enough to know the velocities of stars - the spatial density of the modelled population is as important. This is one reason why it is vital to really understand the selection effects affecting a survey.