Equivalent width of HαW(Hα) vs. diagnostic ratio [Nii]λ6583/Hα. Upper panels: sources with detections and upper and lower limits. Bottom panels: sources with detection only. Leftmost panel are for sources belonging to clusters, panels on the right are for control sources: w0 (second from left) and one realization of w0_t,M  and of . Dividing lines are drawn according to Cid Fernandes et al. (2010), separating Hii, strong AGNs, weak AGNs, and retired galaxies. The dot-dashed line indicates a limiting [Nii]λ6583/Hα ratio for extragalactic nuclear Hii region. Color coding identifies Hii, TO, LINERs, and Seyfert as in the previous figures. Black data points identify ELGs with no entry in DD_[NII].