Preheating and the lowest temperature galaxy groups

The lowest temperature galaxy groups are of special interest, since in thesesystems the energy injection from galaxy winds has the most extreme effect. Theyalso contain a large fraction of the baryons in the universe, due to their highspace density. However their low Xray surface brightness has made them theleast observed and most poorly understood class of galaxy systems. XMM, with itslarge effective area presents the first chance to study these systems in detail.We propose to study three of the lowest temperature galaxy groups known in orderto determine their structure, and the amount and source of energy injectionwhich has profoundly affected them. We also intend to study the amount hot gasin these systems and so quantify their contribution to the global baryon budget. truncated!, Please see actual data for full text [truncated!, Please see actual data for full text]