We report optical imaging and spectroscopy of 41 galaxies in a 22' square region surrounding Cygnus A. The results show that there is an extensive rich cluster associated with Cyg A of Abell richness of at least 1 and possibly as high as 4. The velocity histogram has two peaks, one centered on Cyg A and a more significant peak redshifted by about 2060 km s~-1 from the velocity of Cyg A. The dynamical centroid of the spatial distribution is also shifted somewhat to the northwest. However, statistical tests show only weak evidence that there are two distinct clusters. The entire system has a velocity dispersion of 1581 km s~-1, which is slightly larger than other, well-studied examples of rich clusters.
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机译：我们报告了在天鹅座A周围22'正方形区域中41个星系的光学成像和光谱学。结果表明，与Abell丰富的Cyg A相关的广泛丰富集群至少为1，可能高达4。速度直方图有两个峰，一个集中在Cyg A上，另一个更显着的峰从Cyg A的速度红移了约2060 km s〜-1。空间分布的动态质心也有些向西北移动。但是，统计检验仅显示了两个明显不同的集群的微弱证据。整个系统的速度色散为1581 km s〜-1，比其他经过充分研究的富星团实例稍大。
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