Paper detail

The Dynamics of the Wide-Angle Tailed (WAT) galaxy cluster Abell 562

We present the first in depth dynamical analysis of the archetypal Wide-Angle Tailed (WAT) cluster Abell 562. We have combined Gemini observations with archival data from the literature to form a sample of 76 cluster members and derived a mean redshift of $0.1088 \pm 0.0004$ and a velocity dispersion of $919 \pm 116$ km s$^{-1}$. This relatively large velocity dispersion suggests either a very massive cluster ($M_{dyn} > 6.9 \times$ 10$^{14}$ $M_{sun}$) and/or a merger system. The merger model is supported by a non-Gaussian galaxy velocity distribution, an elongated spatial distribution of likely cluster members, and an elongated X-ray emitting gas. This scenario would generate the bulk flow motion of the intra-cluster medium that can exert enough ram pressure to bend the radio jets. Thus, our observations support the model in which a recent off-axis merger event produced the cluster wide conditions needed to shape the WAT in Abell 562.