An XMM-Newton Survey of NORAS Groups of Galaxies

We propose an XMMNewton survey of nearby groups from the representative fluxlimited NORAS sample. Our proposed sample spans the range of Xray luminosities(and thus temperatures) for groups. The high signaltonoise data we obtain willbe used to derived entropy profiles from the very centers of these groups out toapproximately half of the virial radius. These entropy profiles will be used toconstrain the history of heating and cooling in groups. The XMM data will alsoallow a detailed study of the abundance gradients of the hot gas in the elementsof Fe, O, Si and S, which provide constraints on the stars responsible for theenrichment. Finally, we will measure accurate mass and baryon profiles and thusdetermine the contribution of groups to the mass density of the universe. truncated!, Please see actual data for full text [truncated!, Please see actual data for full text]