Periodograms for certain time periods corresponding to different sector structures of the IMF, the daily number of dust impacts with morphological types A and B (left, indigo curves), and the sector boundary structure (right, teal curves). All selected time periods last 1 yr. The axes of the periodogram amplitude are scaled identically within each column. The vertical lines are as in Fig. 14. The estimated 95% significance thresholds are indicated by grey shaded areas.