Period spacing and mode identification for independent g-modes. (a) Kolmogorov-Smirnov (KS) tests on two period sets with ℓ = 1. Two vertical segments locate the minimum values for preliminary spacing. (b) Period difference between consecutive modes of the ℓ = 1 and ℓ = 2 sequences, after converting to reduced periods. (c) Échelle diagram for dipole (left) and quadruple (right) modes. The vertical curves represent the corresponding period for rotational components, with 3 and 5 for triplet and quintuplet, respectively. The red and blue + symbols represent the splitting frequency components for ℓ = 1 and ℓ = 2, respectively. And the yellow cycle indicates the mode in ℓ = 2 with a larger deviation in frequency splitting values. The modes surrounded by the solid circles are possibly identified to be trapped modes.