Scaling relations with a complete sample of galaxy groups

Lorenzo Lovisari (AIfA/Bonn)

 

Galaxy clusters are an attractive tool to constrain cosmological parameters and well-determined scaling relations between X-ray observables and cluster mass give us a precious diagnostic to study the thermodynamical history of the intra-cluster medium (ICM). Scaling relations have been investigated extensively for galaxy clusters, however the question of whether these relations hold true also for galaxy groups remains unsettled. We are in the process of improving the accuracy of scaling relations using a complete sample of 23 groups to study if there is a systematic difference between clusters and groups and the influence of non-gravitational physics on low-mass systems. By combining this sample with the HIFLUGCS creates a master sample of 87 groups and clusters ranging over more than three orders of magnitude in luminosity. This large leverage will directly allow us to place tight constraints on cosmological parameters.