Full-band 25″ × 25″ images of the X-ray detected, spectroscopically unidentified ALMA sources in the outskirts of the DRC field (Ivison et al. 2020). The R = 2″ red circles are centered on the X-ray positions. The green contours mark the 3 mm emission of the continuum source in the field of sub-mm source F. Blue contours mark the CO(4-3) line emission for the unidentified line emitters (not matched with continuum emission) in the fields of sub-mm sources F and G (see Ivison et al. 2020 for details).