Diagnostic diagrams with fluxes of UV emission lines for the different stack sets, color-coded by the parameter used for stacking. Symbols are the same as in Fig. 11. The red and cyan points are the photoionization models for AGN (Feltre et al. 2016) and SF (Gutkin et al. 2016) for metallicity Z = 0.0001, 0.0002, 0.0005, 0.001, 0.002, and for ionization parameter log(U) = −4, −3, −2, −1. The dotted-dashed lines in the bottom panel separates composite and AGNs according to Hirschmann et al. (2019).