Example of an ALMACAL−22 data cube from the updated sample with a prominent emission line found in the calibrator field. The top panel shows the full spectral coverage of the region of the data cube where the emission line was found. The lower left panel displays a region of the continuum map of the calibrator field in Band 3, centred on the position of the emission line. The lower right panel shows the emission line, where the shaded region represents the line width reaching a S/N ∼9.