Associations with H₂O masers. Top: 21 μm to 1.2 mm flux ratio versus the normalized angular separation between millimeter and infrared sources as in Fig. 9. Colored filled dots show those objects associated with H₂O masers detected with ATCA (see Table 4). The numbers at the top of the panel indicate the percentage of association of H₂O masers in each of three groups. Bottom: histograms of the normalized angular separation for the different groups. The solid black lines correspond to all sources of each group and the colored filled histograms correspond those objects associated with H₂O masers.