Extended Data Fig. 2: Periodicity analysis of FRBs 20210206A and 20210213A.

a,b, Power spectrum obtained with a discrete Fourier transform of the pulse profile. Vertical pink lines indicate the periods reported in Extended Data Table 1. c,d, Residuals of a timing analysis assuming that the peaks forming the FRB profile are separated by integer numbers times these periods, respectively. 1σ error bars are often smaller than the symbol sizes. Horizontal pink lines indicate a phase of zero around which residuals have been rotated. e,f, Study of the statistical significance of the measured periodicity by using the periodicity-sensitive score \(\hat{S}\). The grey histograms have been obtained with an ensemble of simulations, whereas the value measured for each FRB is represented with a vertical pink line. The corresponding probability of obtaining such a periodicity by chance is indicated on the plots. a,c,e, FRB 20210206A. b,d,f, FRB 20210213A.