Lyman-α emission toward the SPT2349-56 protocluster system at z = 4.3. Left: the area covered by MUSE is shown, with the HST F160W image in the background in gray scale, and red contours representing a rendered Lyman-α image. The latter was obtained as the average of each individual line map of the detected LAEs and the LAB, in steps of 2, 5, and 7σ, where σ is the rms noise level in the average image. The blue circles highlight the locations of the ALMA [C II] and CO(4–3) line detections in the field (Miller et al. 2018; Hill et al. 2020). Green squares show the locations of the LBGs in the field (Rotermund et al. 2021). Right: map of ALMA [C II] line emission toward the identified Lyman-α blob (LAB) shown in the background, with blue circles representing the location of the previously identified [C II] line emitters C10, C14, and C17 (see Table 2; Hill et al. 2020). Red contours show the Lyman-α emission of the LAB at 2, 5, and 7σ.