Large Magellanic Cloud-induced
reflex motion of the Milky Way

In two papers, we detail the prediction and detection of so-called reflex motion of the Milky Way disc in response to the infall of the Large Magellanic Cloud. In the first, we predicted an observable signature in the stellar halo of the Milky Way. In the second, we detected the predicted signature, conclusively showing that the Milky Way halo may not be considered to be in equilibrium.

Project Overview

Simulating the interaction of the Milky Way and Large Magellanic Cloud is difficult. Making a schematic is much easier, and more fun, so we'll start there:


A schematic view of the MW-LMC interaction

The Large Magellanic Cloud (red) approaches the Milky Way (blue). The principal effect is the displacement of the Milky Way disc from the barycentre of the galaxy -- up to tens of kiloparsecs!


This displacement has many additional effects, which we are actively researching right now. We love to collaborate, so please reach out if you have any ideas!

American Astronomical Society's 2021 Division of Dynamical Astronomy meeting

I contributed a talk presenting reflex motion and other assorted results for the interaction of the LMC and MW. The material in the talk is approximately half published -- a nice mixture of the recent results and some work where we are looking ahead.(Transcript here)



Discussion elsewhere

We were very fortunate to have the work published in Nature Astronomy, which led to a new learning experience for me of how science is communicated. One of the best articles putting the work in context was published in Quanta magazine, available here. There is also an accompanying podcast that draws from the interview for the article. You can see the full Altmetric summary of the coverage here. I also wrote a 'Behind the Paper' post describing some of the process that went into finding our results. I'm more than happy to provide feedback on the experience!

A big highlight of the press coverage for me was being interviewed (live -- you'll be able to tell) by the BBC. Take a listen!