Testing the Origin and Evolution of Fossil Groups of Galaxies with XMM-Newton

Fossil groups (FGs) present a puzzle to current theories of structure formation.Despite the low number of bright galaxies, their high sigma and high gas T_Xindicate clusterlike potential wells. The measured c200 seem are highindicating early formation epochs, in contradiction with the observed lack oflarge cool cores. There are few FGs with deep Xray data to date, and theiridiosyncratic characteristics may contribute to enhance these apparentcontradictions. To zero in on their origin and formation mechanisms it isfundamental to increase the number of FGs with good quality Xray data. Here, wepropose to build the 1st large Xray sample of bonafide FGs. True diffuseemission has been verified through 2 Chandra programs. This will allow us to significantly constrain FG.s formation mechanisms. truncated!, Please see actual data for full text [truncated!, Please see actual data for full text]