Multi-wavelength imaging of BX610. (a) CO (4–3) integrated intensity map. The overlaid white contours correspond to the 3, 5, 7, 10, 20, 40, and 60σ levels. The filled circle at the bottom left corner indicates the ALMA-synthesized beam (θ = 0.18″ × 0.18″). (b) [CI] (1–0) integrated intensity map. The overlaid white contours, as in panels (c) and (d), represent the rest-frame optical emission observed by HST NICMOS/NIC2 F160W, corresponding to fractional flux levels relative to the maximum of 0.25, 0.5, and 0.75. (c) Rest-frame 630 μ m dust continuum emission. (d) Hα integrated intensity map. The filled circle at the bottom left corner indicates the SINFONI Hα point-spread function (θ = 0.24″ × 0.24″).