Upper panel: Total irradiance of the Sun during cycle 23 based on SOHO/VIRGO data. The solid black line corresponds to the 30-d moving average. Medium panel: LS analysis of the TSI data for the whole frequency range. The meaning of lines and arrows are the same as in Fig. 1. Bottom panel: Wavelet analysis of the TSI in the range 150−450 d. The significance level of all power peaks is below 5% and for this reason the confidence level contours are not plotted. We only consider peaks that are consistent with Rieger periodicity and 1-year cycle. Longer period features are not classified as Rieger-type cycles.