Canadian Cluster Comparison Project


The Canadian Cluster Comparison Project (CCCP) is a study of a large sample of X-ray selected clusters with the aim of examining the relationship between baryonic tracers of cluster mass and to probe the cluster-to-cluster variation in the thermal properties of the hot intracluster medium (ICM). Previous studies were hampered by inhomogeneous data sets and small samples. The CCCP remedies this problem using a sample of 50 massive X-ray selected clusters of galaxies.

We have obtained deep imaging data from the Canada-France-Hawaii Telescope (CFHT) which we use to determine the cluster mass directly using weak gravitational lensing. Comparison with existing X-ray and SZ data, as well as the optical properties allows us to calibrate the various mass-tracer relations, which is important for planned large cluster abundance studies. In addition detailed comparison with simulations and X-ray observations will enable us to study the physical origins of these relations and their scatter, thus improving our knowledge of cluster formation, including their central galaxies.

The team: The CCCP started out as a relatively modest project, involving the list of core-researchers listed below:

Henk Hoekstra (PI)          Leiden Observatory/University of Victoria

Arif Babul                        University of Victoria

Chris Bildfell                   University of Victoria

Andisheh Mahdavi          San Francisco State University

Jonathan Sievers            CITA, University of Toronto

As time progressed, people moved from Canada. Furthermore, other research angles necessarily involved additional researchers across the globe.

The sample: The project started with the analysis of massive clusters observed with the CFH12k camera. This sample was subsequently extended with observations using Megacam of clusters with ASCA temperatures larger than 5keV. Many, although not all, of the clusters have modern (Chandra or XMM-Newton) X-ray data. More details about the sample can be found here. For those who like to look at pretty pictures, we have created a gallery of CFH12k images and a gallery of MegaCam images.


H. Hoekstra (2007), MNRAS, 379, 317 [ADS]

A. Mahdavi, H. Hoekstra, A. Babul, D. Balam, P.L. Capak, (2007), ApJ, 668, 806 [ADS]

A. Mahdavi, H. Hoekstra, A. Babul, J.P. Henry (2008), MNRAS, 384, 1567 [ADS]

C. Bildfell, H. Hoekstra, A. Babul, A. Mahdavi (2008), MNRAS, 389, 1637 [ADS]