tokens: modes first increases as the frequency is higher. It becomes maximum at 12.3 μ Hz and decreases rapidly beyond this frequency. Group C-II is composed of four frequencies above 12.5 μ Hz, which have non-consecutive radial orders. Group C-II shows an isolated high peak of about 1 mmag at 12.85 μ Hz, which is indicated by an arrow in Fig. 6 , while the peaks at the other frequencies are only about 0.2 mmag high. It might appear that the two subgroups originate from different types of modes because the amplitude distribution is clearly different between them. With the assumption of m = −1 and the rotation frequency of 14.9 μ Hz (cf. Table 2 ), we may estimate the spin parameters of the frequencies in group C-II to be 12.9 and above, which is consistent with those of Rossby modes with k = −3 (cf. Fig. 1 ). However, we reject this mode identification of group C-II because we fail to construct the diagram with k = −3 that shows clear alignment of points on a straight line (or a smooth curve), in sharp contrast to Fig. 5 . We thus regard all of the frequencies in group C as those of Rossby modes with m = −1 and k = −2. Still, we do not understand why the amplitude structure of these modes changes suddenly around 12.5 μ Hz. If the amplitude is determined by the mode visibility alone, the envelope of the amplitude in group C-I should extend as far as about the rotation frequency of 14.9 μ Hz (cf. Saio et al. 2018 ). The reason for the isolated peak at 12.85 μ Hz also needs to be explained. While we assume that the amplitude is controlled by the physical mechanism of mode excitation and damping, the problem needs to be discussed in more detail in a separate study. We finally note that the similar amplitude distribution of Rossby modes can also be found in other stars, including KIC 3448365 and KIC 9480469 , the spectra of which are shown in Fig. A2 of Saio et al. (2018) . Fig. 6. Lomb-Scargle periodogram of KIC 3240967 around frequencies of group C. The vertical dotted lines indicate the extracted frequencies given in Table A.1 . 4.2. KIC 12066947 We analysed another γ Dor star, KIC 12066947 , based on the diagram. The amplitude spectrum of the star is shown in Fig. 7 , and the extracted frequencies are listed in Table A.2 . These frequencies were obtained by the method described in Antoci et al. (2019) , and are found in five groups, which we refer to as groups U-0, U-1, A, B, and C in the order of frequency. Group B between 26 and 38 μ Hz consists of Kelvin g -modes with m = 1, and has been analysed in Christophe et al. (2018) and Paper I. On the other hand, group A between 19 and 25 μ Hz can be identified as Rossby modes with m = −1 and k = −2, as in Van Reeth et al. (2016) . We note that in contrast to Christophe et al. (2018) , we find the peaks between 56 and 69 μ Hz (group C) to be statistically significant. This is because after more detailed analyses, we discovered that using only data from the quarters Q10–Q17, hence removing Q0 and Q1 due to
ner_tags: O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B-Formula I-Formula I-Formula O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B-Formula I-Formula I-Formula O O O O O O O O O O O O O O O O O O O O O B-Formula I-Formula I-Formula O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B-Formula I-Formula I-Formula O B-Formula I-Formula I-Formula O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B-Citation I-Citation I-Citation I-Citation O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B-CelestialObject I-CelestialObject O B-CelestialObject I-CelestialObject O O O O O O O O O O O B-Citation I-Citation I-Citation I-Citation O O O O O O B-CelestialObject I-CelestialObject O O O O O O O O O O O O O O O O O O O B-CelestialObject I-CelestialObject O O O O O O B-CelestialObject I-CelestialObject O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B-Citation I-Citation I-Citation I-Citation O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B-Formula I-Formula I-Formula O O O O O B-Citation I-Citation I-Citation I-Citation O B-Citation I-Citation O O O O O O O O O O O O O O O O O O O B-Formula I-Formula I-Formula O B-Formula I-Formula I-Formula O O B-Citation I-Citation I-Citation I-Citation I-Citation O O O O O O O B-Citation I-Citation I-Citation I-Citation O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O