Evolution of the X-ray Profiles of Poor Clusters from the XMM-LSS Survey

Understand

A sample consisting of 27 X-ray selected galaxy clusters from the XMM-LSS survey is used to study the evolution in the X-ray surface brightness profiles of the hot intracluster plasma.

• These systems are mostly groups and poor clusters, with temperatures 0.6-4.8 keV, spanning the redshift range 0.05 to 1.05.
• Comparing the profiles with a standard beta-model motivated by studies of low redshift groups, we find 54% of our systems to possess a central excess, which we identify with a cuspy cool core.
• Fitting beta-model profiles, allowing for blurring by the XMM point spread function, we investigate trends with both temperature and redshift in the outer slope (beta) of the X-ray surface brightness, and in the incidence of cuspy cores.