not detected in the other three observations of this object. In the 58 ks (Obs. ID 159960101) and 60 ks (Obs. ID 126700801) observations of 3C 273, there is a signal at 5000s, but it does not rise above the 99$\%$ red noise confidence level (Fig. \[gwpsall1\]). We note that a Fourier analysis of 3C 273 yielded a feature at 3.3 ks, but with a lower significance ($<$ 3$\sigma$) than is found with the wavelet technique.

We performed Monte Carlo simulations in order to estimate the probability that the wavelet technique would claim a spurious detection. As a baseline, we created one thousand simulated light curves for Poisson photon noise (Fig. 11) to represent random observational errors i.e. photon counting statistics. The simulated light curves were 56 ks long with 5 s intervals and we multiplied the mean deviate $z_{n}$ by 40 to produce an average spread in the y-axis of 40 counts to resemble the 3C 273 light curve. Most of the false detections occur at timescales less than 2000s which corresponds to 3.6 $\%$ the length of the observation and supports our earlier point that one can select the lower limit to search for periodicities by visual identification 