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

TL;DR

This study provides the first detailed dynamical analysis of Abell 562, revealing evidence of a recent off-axis merger that influences the cluster's structure and the morphology of its Wide-Angle Tailed galaxy.

Contribution

It combines new Gemini data with archival data to analyze the cluster's dynamics, supporting the merger scenario as the cause of WAT galaxy morphology.

Findings

High velocity dispersion indicates a massive or merging cluster.

Non-Gaussian velocity distribution suggests ongoing merger activity.

Elongated X-ray gas and galaxy distribution support merger hypothesis.

Abstract

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.