Milky Way & Local Group PhD Projects

Research projects on offer in our Milky Way & Local Group Galaxies research group.

Multiscale disequilibrium in the Milky Way, revealed by Gaia and dark matter models

Prof Jorge Peñarrubia and Dr Michael Petersen

Disc galaxies are fragile structures that are constantly being pushed away from equilibrium -- not just by encounters with other galaxies, but sometimes by their own internal evolution. Even a protective dark matter halo can act as an amplifier for distortions -- through the dynamics of these processes are poorly understood.

The next release of Gaia data will bring a new level of detail to observations of the Milky Way, our home galaxy. From stars that have been funnelled to the inner galaxy, to delicate stellar streams probing orbits in the galaxy, to distant halo stars recording the history of every interaction, a new generation of modelling techniques is required to make sense of the deluge of data.

In this PhD, a suite of projects will be undertaken around the theme of disequilibrium in the Milky Way, across all scales. The primary tool will be the development of a statistical treatment of disequilibrium features, with a focus on astrophysical 'noise' from small-scale potential fluctuations, induced by giant molecular clouds and dark matter subhalos. The statistical tool, once developed, will be coupled to high performance computing software to model the entire Milky Way. The student will compare data from the Gaia mission against these models. The goal is to create a rich dynamics playground for studying regimes of disequilibrium in the Milky Way. The construction of dynamical tools that can model observations of the Milky Way out of equilibrium is a fundamental step in getting at a fundamental mystery in the Milky Way: how does dark matter constructively or destructively influence dynamical evolution?