[Cymraeg]

Physics projects for Y3 and Y4 students


Project description

Einstein ring -- gravitational lensing

(supervisor: Xing Li)

Nature of project: data analysis, theory

Available to students on full-time physics degree schemes only.

Project description and methodology

Einstein's theory of general relativity predicts that a gravitationally compact body can act as a lens for light from a more distant object. In perfect condition, the distance object can be seen as a ring (Einstein ring). Normally the lensing effect is quite small for a star. However, a galaxy cluster's enormous gravity makes the lensing effect prominent. This project will use Hubble images of galaxy Clusters (for example, Abell 2218) to show the gravitational lensing effect. The effect can be used to infer various information such as the mass of the galaxy cluster involved and distribution of dark matter in the cluster.

A successful project will develop beyond the above in one/some of the following directions:
A first class report of the project will very likely include detailed description of the theory of Einstein's gravitational lensing.

When considering where to take your project, please bear in mind the time available. It is preferable to do fewer things well than to try many and not get conclusive results on any of them. However, sometimes it is useful to have a couple of strands of investigation in parallel to work on in case delays occur.

Additional scope or challenge if taken as a Year-4 project: In additional to the requirements above, a 4th year project may also look at dark matter in chosen galaxy clusters in detail.

Please speak to Xing Li (xxl) if you consider doing this project.

Initial literature for students:

  1. Einstein, A., Science, 84, 506 (1936)
  2. Wambsganss, J., Living Reviews in Relativity, 1, 12, 1998.
  3. Struble, M.F., and Rood, H.J., Astrophysical Journal Supplement Series, 63, 555, 1987.
  4. Hubble legacy archive, https://hla.stsci.edu/hlaview.html

Novelty, degree of difficulty and amount of assistance required

Can be fun for some students. Successfully run in 2019-2020.

Project milestones and deliverables (including timescale)

milestoneto be completed by
Basic understanding of general relativityend of November
Basic understanding of gravitational lensingChristmas
Able to manipulate Hubble imagesend of February
Able to interpret images.mid-March