X - ray properties of head - tail radio sources in clusters of galaxies

From ROSAT imaging data we have detections and upper limits for a sample of 26 tailed radio sources in clusters of galaxies mostly from the sample of O’Dea & Owen (1985). All sixteen of the detected sources are unresolved in the ROSAT PSPC images. The sources bright enough to perform X-ray spectral analysis have power-law indices similar to BL Lacs and Seyfert galaxies. We find that there is a highly significant correlation between the core radio flux density and the X-ray flux but only a weak correlation between the total radio flux density and the X-ray flux. The trend is similar to that found in earlier studies of 3C radio galaxies with Einstein and more recently with ROSAT. The result adds an additional constraint on models for the unification of BL Lac objects with FR I radio sources. Also this result indicates that the observed enhanced X-ray emission near tailed sources is more likely to be due to nuclear emission rather than substructure in the extended cluster gas.