NIR diagnostic diagram, adapted from Larkin et al. (1998) and Rodríguez-Ardila et al. (2004, 2005). The different domains of the plot, labelled “SB” (starburst), “AGN” and “LINERs” have been shown to provide a basic classification of galactic nuclei. We only plot the result for those apertures where we had significant line detections in all three lines. The side panels show the distributions of the two ratios, differentiated by nuclear (black, dashed) and off-nuclear (gray, solid) environment.