Dr Sophia Lilleengen
Academic and research departments
Faculty of Engineering and Physical Sciences, Astrophysics Research Group.About
My research project
The effect of the deforming dark matter halos on stellar streamsThe Milky Way and the Large Magellanic Cloud are merging. As a result, their dark matter halos are deforming. I am investigating whether this has an effect on visible objects in the halo, such as stellar streams. Currently, I study this effect on the Chenab stream.
Supervisors
The Milky Way and the Large Magellanic Cloud are merging. As a result, their dark matter halos are deforming. I am investigating whether this has an effect on visible objects in the halo, such as stellar streams. Currently, I study this effect on the Chenab stream.
To get involved with the broader PGR community at the University, I joined the Doctoral College Conference organising committee. We planned and executed an interdisciplinary conference for PGRSs and ECRs, New Horizons 2020, with over 300 attendees. Due to the pandemic we ran it only. It was a great success and highly commended.
Based on expertise and knowledge from organising the DC conference, I was invited to join the Research Culture Week organising committee. This event in November 2020 consistent of 2 talks per day for a week, with a different focus on a research culture topic each day.
New Horizons DC Conference: https://nhdcc20.wordpress.com/
REACH Research Culture Week: https://surreyreach.github.io/
News
In the media
Publications
Many astrophysical and galaxy-scale cosmological problems require a well determined gravitational potential which is often modeled by observers under strong assumptions. Globular clusters (GCs) surrounding galaxies can be used as dynamical tracers of the luminous and dark matter distribution at large (kpc) scales. A natural assumption for modeling the gravitational potential is that GCs accreted in the same dwarf galaxy merger event move at the present time on similar orbits in the host galaxy and should therefore have similar actions. We investigate this idea in one realistic Milky Way like galaxy of the cosmological N-body simulation suite Auriga. We show how the actions of accreted stellar particles in the simulation evolve and that minimizing the standard deviation of GCs in action space, however, cannot constrain the true potential. This approach known as `adaptive dynamics' does therefore not work for accreted GCs.