Absence of detectable X rays from supercluster candidate 4U0134-11

A CORRELATION between a small subset of high galactic latitude X-ray sources and superclusters of galaxies has been suggested¹. The existence of superclusters (that is, clusters of clusters of galaxies) was first discussed in the context of optical observations^2,3. A hot intrasupercluster gas could lead to detectable X-ray emission as well as provide a large fraction of the mass necessary to close the universe⁴. The Goddard, Space Flight Center Cosmic X-ray Spectroscopy experiment onboard Orbiting Solar Observatory 8 (OSO 8) scanned directly over the position of 4U0134-11, one of the three 4U sources associated with a supercluster. We did not observe X rays from this source with an upper limit to the source strength a factor of 6 below the catalogued Fourth Uhuru (4U) strength.