Emission maps for HDCO 4(2,2)−3(2,1). Left panel: HDCO 4(2,2)−3(2,1) moment 0 map integrated between −1 and 7 km s⁻¹ that peaks at the position of the dust emission. Observations performed using both 12 m and 7 m ALMA configurations are combined in this map in order to investigate both large- and small-scale structure. Contours start at 4σ and end at 10σ in 3σ increments (σ = 4.1 mJy beam⁻¹ km s⁻¹). The 4σ contour is highlighted in cyan as this is the contour that served as the extraction polygon for all spectra shown in this work. Right panel: Moment 1 map of HDCO 4(2,2)−3(2,1) integrated between −1 and 7 km s⁻¹, in order to directly compare with the moment 0 map and to show the velocity structure of the disk. In both maps, the locations of the protostars A and B are shown by black stars. The ALMA synthesised beam is in the lower left corner.