a) The W51 IRS2 region in C-band continuum and b) unsharp masked with a 0.3′′kernel. Concentric ring features surround the IRS2 region. A V-shaped feature to the north (cyan arrow) may highlight the edge of gas flows out of the cluster, extending to the long linear feature pointing northwest (blue arrow). An apparent shell is observed centered on the IRS2 cluster, with edge features to the south and east (red arrows). The compact sources d6 and d7, which are candidate colliding-wind binaries (Sect. 4.2), are identified with green arrows.