Are there Hot Gas Haloes in Elliptical Galaxies with Large-scale Dust Lanes

We propose to observe luminous, old elliptical galaxies containing large, regular dust lanes for which the settling time scale is several Gyr. The aim is to find out if such galaxies contain massive haloes of hot (T<virgul1 keV) gas. If found,the theory of grain sputtering in hot gas would need revision, as it predicts a grain life time of only <virgul10 Myr, a tiny fraction of the age of the large dust lanes. On the other hand, if no hot gas is found, these very luminousellipticals are not able to retain the gas produced by stellar evolution. Theimplication would be that in order for an elliptical to retain its stellarmass loss, it has to be located in a potential well that is deeper than thatof the galaxy itself (e.g., in centers of (sub)clusters or rich groups). truncated!, Please see actual data for full text [truncated!, Please see actual data for full text]