The large-scale ( \sim 20 \arcmin ) diffuse x-ray background surrounding a sample of quasars observed during ROSAT PSPC pointed observations is studied using a new source-detection algorithm , the scaling-index method .
This algorithm , which can identify individual photons as belonging to a source or background , is useful for detecting faint , extended sources in noisy fields .
Using this method , we find that , contrary to conclusions drawn by others , there is scant evidence for preferential enhancement of x-ray backgrounds surrounding radio-loud quasars by foreground x-ray emitting clusters of galaxies .
Rather , all fluctuations in these backgrounds can be explained by varying levels of emission from a galactic thermal plasma of temperature T \approx 0.14 keV .
No difference is observed between the diffuse x-ray backgrounds of radio-loud and radio-quiet quasars .