Clusters are the most massive bound structures in the Universe and are a unique place to study galaxy formation. Around half of the stellar mass of the Universe is produced in clusters or their proto-cluster ancestors. Tracing proto-clusters in the distant Universe is difficult as traditional techniques become much less effective. However, the most powerful radio sources are unique beacons of the earliest over-densities which form proto-clusters. Using radio surveys we have discovered many high redshift proto-clusters associated with powerful radio galaxies.
Many of these high redshift radio galaxies are extremely polarised with unusual polarisation properties. As the radio emission is large, >100,000 parsec in the case of the Spiderweb galaxy below, it is not clear how sources so big can have such unusual radio properties. One prevailing argument is that it is partly due to the intra-cluster medium, the dense environment withing the gravitational well of the cluster, but between the galaxies.
This project would utilize a wealth of archival radio observations on these well studied sources as well as low-frequency radio observations from the Murchison Widefield Array (run by Curtin and located in Western Australia). The student would need to develop a good understanding of radio astronomy and the astrophysics of powerful radio sources and clusters in the early Universe.
Dr Guillaume Drouart
Research AssociateRead More