The X-ray properties of optically-selected galaxy clusters

In the next few years, new surveys in X-ray and optical wavebands will become available, leading to the possibility to study clusters of galaxies at greater distances and lower masses than ever before. In particular, the study of the X-ray properties of optically-selected galaxy groups and clusters will be extremely powerful, as the optical selection enables the study of clusters systems that may not be detectable in their X-ray emission alone. In this project, we will measure the X-ray properties of clusters of galaxies that are detected in the optical/infra-red by using forced X-ray photometry at the locations of the optical detections. We will develop a Bayesian inference tool to constrain the properties of clusters in the limit of very low signal to noise X-ray data, enabling us to study fainter systems than has previously been possible. This will be applied to the existing XXL cluster survey data as a prototype and then extend to larger survey data that will begin to become available over the course of the PhD.