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J.N. Bregman, E. Miller, J.A. Irwin (University of Michigan)
In the cooling flow picture, hot X-ray emitting gas cools through line emission, so the luminosity of key cooling lines are proportional to the net cooling rate. Perhaps the best line diagnostics for measuring the cooling rate are the UV OVI lines, which trace the gas cooling through 3E5 K, at which point the gas has lost more than 95% of its initial energy. We used FUSE to measure or place limits on the OVI line luminosity for a sample of 23 early type galaxies. About a quarter of the galaxies have OVI lines detected and they are generally galaxies with an abundance of X-ray emitting gas, a result expected from the cooling flow picture. None of the optically bright but X-ray faint sources are detected, also as expected since these are believed to have galactic winds in which the gas flows outward instead of cooling. However, several X-ray bright galaxies are not detected in the OVI lines, with limits below the cooling rates predicted from X-ray observations. These results may indicate that cooling flows are not steady in time. We would like to thank NASA and the FUSE team for their assistance and support.