A Systematic Study of Fossil Groups

We will observe 3 candidate fossil groups identified using SDSS and RASS. Thedozen previously known fossil groups show normal Xray group properties, buthave optical properties that are dominated by a bright central galaxy. Theformation of such systems is not understood, although various mechanisms havebeen suggested. We will measure the luminosities, surface brightnesses, andradial temperature profiles and correlate with the optical data. Some of thesesystems show an excess Xray luminosity (with respect to their temperatures oroptical properties) which could be explained by cooling, entropy, or inefficientstarformation. By combining with Nbody/Hydro simulations, we will learn abouttheir abundances and formation mechanisms. truncated!, Please see actual data for full text [truncated!, Please see actual data for full text]