We have searched the far-UV spectra of five clusters of galaxies observed with the Hopkins Ultraviolet Telescope ( HUT ) for emission in the resonance lines of \ion O6 \lambda \lambda 1032 , 1038 and \ion C4 \lambda \lambda 1548 , 1551 .
We do not detect significant emission from either species in any of the spectra .
Lieu et al .
[ ApJ , 458 , L5 ( 1996 ) ] have recently proposed a warm [ ( 5 - 10 ) \times 10 ^ { 5 } K ] component to the intracluster medium ( ICM ) to explain excess 0.065–0.245 keV flux present in EUVE and ROSAT observations of the Virgo cluster .
If the surface brightness of this warm component follows that of the hot , x-ray-emitting gas ( i.e. , is centrally condensed ) , then our upper limit to the \ion O6 surface brightness in M87 is inconsistent with the presence of substantial 5 \times 10 ^ { 5 } K gas in the center of the Virgo cluster .
This inconsistency may be alleviated if the central gas temperature is \gtrsim 7.5 \times 10 ^ { 5 } K. HUT limits on the \ion O6 surface brightness of the four other clusters can provide important constraints on models of their ICM .