1919+479 - BIG WAT IN A POOR CLUSTER

New x-ray, optical, and redshift data are presented for the cluster of galaxies associated with the giant, 1 Mpc diameter, wide-angle tailed (WAT) radio galaxy 1919+479. The ROSAT PSPC pointed observation shows an x-ray peak on the WAT and elongated diffuse emission tracing the g alaxy distribution. In addition, an asymmetric extension of emission e xists between the tails of the WAT The fitting of a Raymond-Smith ther mal model to the x-ray spectra suggests an approximate to 2 keV temper ature intracluster medium. The cooling time and irregular morphology r ule out a cluster-wide cooling flow. The x-ray luminosity and temperat ure are consistent with the velocity dispersion, 480 km s(-1), estimat ed from 31 galaxy velocities. However, this velocity distribution is s ignificantly non-Gaussian, which along with the x-ray morphology, sugg ests incomplete virialization in the cluster. Substructure analysis do es not reveal significant clumping in the velocities/positions; but, t he spatial distribution of galaxies is very elongated. Also, the cD ga laxy producing the WAT does not have a significant radial peculiar vel ocity with respect to the cluster centroid. These characteristics are consistent with a merger scenario in which a subcluster has crossed th e cluster core in the plane of the sky and has dispersed. We compare t his cluster with the post-merger cluster Abell 2634 [Pinkney et al., A pJ, 416, 36 (1993)], containing the prototype WAT, and with a recent N -body/Hydro simulation of merging clusters. The similarities indicate that the cluster 1919+479 may be the poor extreme of a class of cluste rs in which the bulk motion in the ICM, caused by a subcluster merger, is shaping the central WAT.