CI_Hα/cont values based on the concentration defined (Formula 8) from Wang et al. (2022) (black: SFS0s_HE; red: SFS0s_LE). The mean CI_Hα/cont of galaxies in HDEs and LDEs is $-0.{04}_{-0.38}^{+0.27}$ and $0.{07}_{-0.25}^{+0.10}$, respectively. The curves on the top and right illustrate the distributions of the parameters on the horizontal and vertical coordinates. The KS_test and T_test results are represented by the blue numbers.