QPOs in the time domain: an autocorrelation analysis

Autocorrelation and discrete correlation methods have been applied to AGN variability and stellar sources but the technique has been underexploited in the analysis of quasi-periodic oscillations in cataclysmics. The authors present a particulary careful study of the sensitivity of this method to various model and statistical artifacts and its use in recovering information in nonperiodic signals. While the power spectrum is the Fourier transform of the ACF, the correlation function analysis is easier to interpret for complex signals.