BPT diagram for galaxies and AGN from the MAMBO light-cone selected with z ≤ 0.8 and $m_{H_{\text{E}}}<24$. Galaxies are shown in grey, while AGN are colour-coded from blue to red according to the ratio of the emission line flux of [O III] from the AGN component with respect to thetotal(AGN+hostgalaxy). Objects from theSDSSDR8 areshown in green in the background, and are traditionally classified as SF galaxies if the fall at the left of the Kauffmann et al. (2003), as AGN if they fall at the right of the Kewley et al. (2001) line, or as composite if they fall in between these two lines.