FUSE Limits on FUV Emission from Warm Gas in Clusters of Galaxies

We have obtained FUV spectra of two clusters of galaxies with FUSE, the Far Ultraviolet Spectroscopic Explorer. The Coma cluster was observed for a total of 28.6 ksec, the Virgo cluster for 10.9 ksec. Neither spectrum shows significant O VI (1032, 1038 A) emission at the cluster redshift. Such emission would be expected from the warm [(5-10) x 10^5 K] component of the intracluster medium that has been proposed to explain the excess EUV and SXR flux present in EUVE and ROSAT observations of these clusters. Our 2-sigma upper limits on the O VI 1032 A flux from Coma and Virgo exclude all published warm-gas models of the EUV excess in these clusters.