J. Pinkney

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 clusters that contain wide- angle tailed (WAT) radio galaxies. The sample of WAT clusters was selected from a VLA radio survey of the Abell catalog 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 clusters also have clear evidence of isophotal twisting, ellipticity variation, and isophote centroid variation as a function of distance from the central X-ray peak. Moreover, none of these WAT clusters have signi—cant cluster-wide cooling —ows in spite of the presence of dominant elliptical (radio) galaxies. We performed temperature —ts to the X-ray emission by applying a Raymond-Smith —t to the spectra and a ii broadband ˇˇ temperature technique. One strik- ing correlation with the radio sources was discovered: there is a strong relationship between the orienta- tion of the WAT tails and the direction of X-ray elongations within the core of the clusters. We believe that this is consistent with WAT clusters undergoing mergers with groups or subclusters of galaxies. We compared our results with numerical hydro/N-body simulations of merging galaxy clusters to test this hypothesis. We found that the X-ray synthetic images generated by the simulations reproduce all the major morphological properties that we found in our sample. Furthermore, the simulations also show that the bulk —ow of gas within the ICM present during the merger could be responsible for the corre- lation between the X-ray elongations and the direction of the bending of the radio tails. Subject headings: galaxies: clusters: generalgalaxies: interactionsgalaxies: structure ¨ intergalactic mediumradio continuum: galaxiesX-rays: galaxies

The dynamics of the galaxy cluster Abell 2634

We have collected a large sample of galaxy velocities for the nearby, rich cluster of galaxies Abell 2634, which contains the prototypical wide-angle tailed (WAT) radio source 3C 465 associated with the central cD galaxy. Robust indicators of location (i.e., velocity mean) and scale (velocity dispersion) and their confidence intervals are used to determine the velocity structure of the cluster. We find a cD peculiar radial velocity of −219±98 km s −1 . The Dressler-Shectman δ-test reveals significant deviations in the local dynamics on the east side of the cluster, probably due to subcluster contamination. The velocity distribution is Gaussian except for a few outliers, where the velocity outliers tend to be spatial outliers

WFPC2 observations of the cooling flow elliptical in Abell 1795

We present results of RXTE observations of the low-mass X-ray binary and atoll source 4U 1608

Clumped X‐ray emission around radio galaxies in clusters: New tools for investigating cluster evolution

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The dynamics of the rich cluster A2634

52 made over 9 days during the decline of an X-ray intensity outburst in March 1996. A fast-timing analysis shows a strong and narrow quasi periodic oscillation (QPO) peak at frequencies between 850 and 890 Hz on March 3 and 6, and a broad peak around 690 Hz on March 9. Observations on March 12 show no significant signal. On March 3, the X-ray spectrum of the QPO is quite hard; its strength increases steadily from 5 \% at

The Morphology Metallicity Connection In Rich Galaxy Clusters

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A study of the frequency of substructure in 80 Abell clusters based on optical redshift data

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WAT Radio Galaxies as Indicators of Galaxy Cluster Evolution

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X-ray Emission from Radio Galaxies in Rich Clusters

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Recent ROSAT X-ray Observations of Galaxy Clusters with Wide-Angle Tailed Radio Sources

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