Constraining galaxy cluster mass with Sunyaev-Zel'dovich observations of clusters of galaxies.
Tuesday 22 May 2012
to 14:15 at
Malak Olamaie (University of Cambridge)
Determining the properties of clusters of galaxies such as their total and baryonic mass offers an independent and powerful cosmological tool to constrain the parameters of the ΛCDM model. The mass distribution of clusters is usually measured using a variety of observational methods, including X-ray, Sunyaev-Zel'dovich (SZ) and gravitational lensing analyses. These methods are often based on parameterised cluster models for the distribution of the cluster dark matter and the thermodynamical properties of its intra-cluster medium (ICM). Investigating the effects of different parameterisations and the assumptions made within any parameterised model are, therefore, crucial in extracting cluster physical properties in a robust way. In this talk I discuss three different parameterisations that one could take to analyse the SZ effect from galaxy clusters within a particular model and demonstrate how each parameterisation introduces different constraints and biases in the posterior probability distribution of inferred cluster parameters. Following this, I present an analytic parametric model to describe the baryonic and dark matter distributions in clusters of galaxies with spherical symmetry . I show that the derived radial profiles of cluster parameters using my proposed model with its corresponding assumptions are consistent both with numerical simulations and multi-wavelength observations of clusters. With the scene set, I then discuss the results of the analysis of SZ data from both Planck satellite and the Arcminute Microkelvin Imager.