Diagnostic diagram of the five QPE host galaxies based on Hα EW and relative [N II]/Hα strength, based on the selection criteria presented in Cid Fernandes et al. (2011). RXJ1301, a post-starburst galaxy is located among the LINER-like population due to the relative weakness of the Hα EW; whereas in the BPT diagram, it falls firmly in the AGN locus. 2MASXJ0249 is classified as being dominated by star formation, whereas it falls in the Seyfert part of the BPT diagram. The data used to reproduce this plot are provided in Table A.1.