I'm a researcher at the Institute for Astronomy, part of the Royal Observatory of Edinburgh, part of the University of Edinburgh. I'm interested in how bodies move and interact in and around galaxies.

Using high resolution simulations of galaxies, I develop algorithms to learn from individual orbits and find unique features of potentials.

I can be reached at michael.petersen@roe.ac.uk.


Overview: Milky Way Evolution, velocity fields in barred galaxies, structure formation in barred galaxies. Age indicators of structure in galaxies. Mock stellar catalogs. Dark matter halo dynamics

Bars are the most ubiquitous non-axisymmetric structure observed in the local universe, observed in roughly two-thirds of local galaxies. My work focuses on numerical simulations and analytic calculations to examine detailed physical processes related to the formation and evolution of bars.

One result to come of this work is the discovery of a trapped component in the dark matter halo that mimics the stellar bar, which we refer to as the shadow bar. Click on the image below for a more comprehensive look at the shadow bar work, or read the MNRAS paper.

The shadow bar has consequences for the structure of the dark matter halo at the solar circle.

The combination of the stellar and shadow bar drives non-axisymmetric structure in the dark matter halo--which has consequences for direct detection experiments on Earth. Click on the image below for a more comprehensive look at the implications for direct detection experiments, or read the PhysRevD paper.

Recent Work

Recently, I have been working on the observable effects of the Large Magellanic Cloud on the stellar halo of the Milky Way.

In this work, we are able to isolate the resonances responsible for driving the angular momentum transfer, as well as illuminating when and why those same resonances change efficiency during the simulation.


I'm part of the team organizing the seminar series at the Royal Observatory.


Published work.


See what I'm up to on Github.


I'm also (inactively) on Twitter.