BPT diagram for the isolated elliptical galaxies (black filled squares) of the UNAM-KIAS catalog and elliptical galaxies in the Coma supercluster (red open circles) with estimates from the STARLIGHT database. The typical uncertainty is indicated with the black open symbol with error bars. Blue and green solid points represent the blue SF and red SF isolated E galaxies, respectively. Open blue squares indicate particular measurements for blue SF isolated galaxies using the method described in Appendix C. Solid blue lines just connect the two different measurements for each blue SF elliptical, where the numbers correspond to their ID in the UNAM-KIAS catalog. Galaxies are classified as star-forming nuclei (SFN), transition objects (TO), or AGN (Seyfert/LINER) according to the relations of Kauffmann et al. (2003, solid line), Kewley et al. (2001, dashed line), and Schawinski et al. (2007, dotted line). The dashed arrow indicates that UNAM-KIAS 613 is rather a Seyfert 1.8 because of its broad components in Hα and Hβ (see details in Appendix A).