CO(2−1) moment 0 maps of J1356 integrating over the emission detected in the “W arm,” westward of the N nucleus (left panel; black contours go from 2 to 7σ with σ = 0.0196 mJy beam⁻¹), and in the S nucleus, ∼1.1″ south of the N nucleus (right panel; white contours go from 2 to 5σ with σ = 0.0156 mJy beam⁻¹). The N and S nuclei are connected by a CO-emitting bridge or spiral arm. The beamsize is indicated in the bottom left corner of each panel.