Left panel: distribution of CO emitters versus their sky distances from the central radio galaxy MRC1138−262. Top panel: histogram (red) and cumulative fraction (blue) of CO emitters as a function of the distances to the center galaxy. Bottom panel: CO emitters are color-coded with their S/N. Gray shaded area marks the redshift range observed by the narrow band N₂₀₇₁ (Shimakawa et al. 2018) of MOIRCS at Subaru. Blue and black dashed lines mark the field of view of VLA and ATCA single pointings, respectively. Right panel: normalized velocity versus distance to center galaxy for CO emitters in this study and HAEs with a spectroscopic redshift (Shimakawa et al. 2018). The normalization factors are σ = 683 km s⁻¹ and R₂₀₀ = 0.53 Mpc (Table 2 in Shimakawa et al. 2014). The two dashed curves show the escape velocity (positive and negative) as a function of distance from the cluster mass 1.71 × 10¹⁴ M_⊙ (Shimakawa et al. 2014) using the prescription of Rhee et al. (2017). Half of the CO emitters in this work have velocities outside of the region enclosed by these two curves that are not expected to be gravitationally bound to the central mass.