UltraVISTA K_s-band image of G237. The spectroscopic members in G237 are shown as open circles (magenta: 2.15 ≤ z < 2.164, and light blue: 2.19 < z < 2.20). SPIRE 350 μm contours are shown in orange, and XMM 4.5–10 KeV contours in blue. Left panel: size of 7′ × 7′, and right panel: zoom of 1.5′ × 1.5′ where the largest densities of spectroscopic members and of X-ray and sub-mm sources are situated.