Statistics of radio halos in galaxy clusters

Project Description:

Galaxy clusters are the most massive, gravitationally-bound structures in the Universe. A fraction of them host Mpc-size radio emission, centred on the cluster itself and believed to be the power by merger-induced turbulence (e.g., Brunetti et al. 2001, Cassano et al.2010). In this scenario the radio emission traces the cluster merger history and there is a linear relationship between the halo radio power and the cluster mass (e.g., Cassano et al., 2013). No radio halo emission is, however, detected down to the sensitivity limit, for a significant fraction of radio clusters. These upper limits affect the power-mass relationship, although they are mostly derived in an empirical way. The candidate will construct a parametric model for the radio halo emission and will use it to derive statistically rigorous upper limits on the radio halo flux density by employing a Bayesian analysis framework. The method will be initially applied to simulated radio images and then will be applied to a few examples of real observations, in order to quantify the difference with previously derived upper limits. If time will permit, the candidate will revisit upper limits for a number of galaxy clusters, updating the luminosity-mass relationship.

Research Area:

Astronomy

Project Level:

Masters

This Project Is Offered At The Following Node(s):

(UCT)

Special Requirements:

Familiarity with Python programming and radio interferometry is preferable but can also be learned throughout the project.