Herschel/SPIRE colour maps of the H-ATLAS (GAMA9, GAMA12, GAMA15, and NGP), HeLMS and HerS fields with the positions of the 137 sources that were observed with NOEMA in the z-GAL project and the Pilot Programme (Neri et al. 2020), highlighted with yellow circles and squares, respectively. The yellow triangles indicate the sources for which spectroscopic redshifts were already available (see Table A.5). The maps display the distribution of the z-GAL sources across the sky and show the proximity of some of the sources that enabled for them to be grouped together during the NOEMA observations, resulting in a more efficient use of telescope time (Sect. 2.2).