The signature of LLAGNs in the nearby universe

We have used the diagnostic diagram that compares the ratio of emission lines [NII]\lambda6584/H\alpha with the equivalent width of [NII]$\lambda$6584, as proposed by Coziol et al. (1998), to determine the source of ionization of SDSS NELGs that cannot be classified by standard diagnostic diagrams, because the emission line [OIII]$\lambda$5007, H\beta, or both, are missing. We find these galaxies to be consistent with low luminosity AGNs, suggesting that this characteristic is the signature of the LLAGNs in the nearby Universe.