Sum of the flux densities from pairs of nearby sources (FS) vs. source separation (x). Top panel: 325 MHz sources; in red, pairs of sources whose flux ratio (integrated/peak) is below 4; in blue, the rest; larger dark gray circles: pairs of confirmed double sources (see text). Dashed line: (x/16)^3.5. Thin solid line: (x/10)². Bottom panel: for 610 MHz sources; in green, pairs of sources whose flux ratio is below 4; in blue, the rest; larger dark gray circles: pairs of double sources (see text). Dashed line: (x/20)^3.5. Thin solid line: (x/16)².