ROSAT X-RAY OBSERVATIONS OF ABELL CLUSTERS WITH WIDE-ANGLE TAILED RADIO-SOURCES

We present new ROSAT PSPC X-ray pointed observations of nine Abell clu sters that contain wide-angle tailed (WAT) radio galaxies. The sample of WAT clusters was selected from a VLA radio survey of the Abell cata log at 20 cm and the ROSAT All-Sky Survey (RASS). We found that up to eight (89%) clusters show some evidence of X-ray substructure. These c lusters also have clear evidence of isophotal twisting, ellipticity va riation, and isophote centroid variation as a function of distance fro m the central X-ray peak. Moreover, none of these WAT clusters have si gnificant cluster-wide cooling flows in spite of the presence of domin ant elliptical (radio) galaxies. We performed temperature fits to the X-ray emission by applying a Raymond-Smith fit to the spectra and a '' broadband'' temperature technique. One striking correlation with the r adio sources was discovered: there is a strong relationship between th e orientation of the WAT tails and the direction of X-ray elongations within the core of the clusters. We believe that this is consistent wi th WAT clusters undergoing mergers with groups or subclusters of galax ies. We compared our results with numerical hydro/N-body simulations o f merging galaxy clusters to test this hypothesis. We found that the X -ray synthetic images generated by the simulations reproduce all the m ajor morphological properties that we found in our sample. Furthermore , the simulations also show that the bulk flow of gas within the ICM p resent during the merger could be responsible for the correlation betw een the X-ray elongations and the direction of the bending of the radi o tails.