YOUNG ELLIPTICALS - DO THEY POSSESS HOT GAS HALOSquestionMark

XMM observations of young elliptical galaxies will determine if they have hotgas in their ISM. Many old, relaxed ellipticals posess such hot gaseous haloes,however the mechanism by which these are created is not understood. Suggestionsare that the hot haloes formed from stellar mass loss or by thermalization ofcold gas infalling from tidal tails after a merger. Correlations of Xrays withage indicate a surprisingly slow buildup of hot gas, over several Gyr. So wheredoes the hot gas come from? We will obtain sensitive XMMNewton observations ofyoung ellipticals (1 3 Gyr) and compare these with data for older ellipticals,to see how the Xray emission evolves. If there is no hot gas in the youngellipticals, then we will get a clean view of the discrete stellar components. truncated!, Please see actual data for full text [truncated!, Please see actual data for full text]