Evidence of galaxy cluster rotation and intrahalo gas motions in the cosmic microwave background
The study detected robust evidence (3.6$σ$) for a dipolar rotational Sunyaev-Zel'dovich (rkSZ) effect in CMB maps centered on 25 massive galaxy clusters. This signal, aligned with the cluster's rotation direction, proves that intracluster gas is rotating and provides a new tool to probe the dynamical state of clusters using CMB data.