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Fig. 4.

Fig. 4. Refer to the following caption and surrounding text.

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Fourier spectra of possible rotational frequencies listed in Table 3. We note that we utilised pre-whitened Fourier spectra for the plots, as the lower-amplitude peaks become more clearly visible after pre-whitening. The horizontal blue lines indicate the significance levels corresponding to a 0.1% FAP for each dataset.

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