Left and central panels are the same as in Fig. 3, but for the MASSIV source 140096645 (no major merger). The level contours mark the isophotes of the original i-band image. The Hα companion source is not detected in the i band. The outer contour marks the 2.64 ADU (1σ_sky) isophote, while brighter isophotes increase in 7.94 ADU (3σ_sky) steps up to 45 ADU to avoid crowded figures. The right panel shows the detection fraction of fake galaxies injected in the i-band image as a function of the magnitude of the companion source m_i,2. The size of the dots marks the detection curves for extended, normal and compact galaxies (see text for details). The vertical line marks the limiting magnitude for major companion (Δm_i = 1.5). (A colour version of this plot is available at the electronic edition.)