BPT distribution for galaxies that were selected by the 2 kpc aperture (circles) but not by the 3″ × 3″ aperture (squares); each pair is connected by a black line. Both catalogs are performed as in Sect. 3.2, with the [OI]/Hα diagram being excluded. Each target is colored by its redshiſt. We plot the empirical division lines that will give each target a specific classification (e.g., AGN-like galaxy, composite object, or HII-star-forming galaxies): red lines correspond to Kewley et al. (2001), and the blue dashed line in the top plot corresponds to Kauffmann et al. (2003a).