Channel maps of the CO(2–1) emission in NGC 1097, integrated over 10 channels (50 km/s). The channel maps are produced from the unmasked data. Contours: The black contours show CO(2–1) emission contours in each channel at 2, 5, 8, 11 × σ, where σ was calculated from a circular annulus (r_in = 250″, r_out = 350″) excluding pixels with line emission and noisy pixels at the edges of the map. Pink contours show negative emission features at a 2σ level. The beam sizes of the APEX (yellow) data are shown in the bottom left, and the bottom right scale bar marks a projected distance of 10 kpc.