Short time-scale X-ray variability of Active Galactic Nuclei

In this work we have investigated short time-scale variability of NGC 4051 and NGC 4388. The quasi-steady QPO’s time scale of 3920$\pm$17 sec was detected for NGC 4051. For the case of NGC 4388 we investigated rapid variability of the parameters of spectral models. To obtain these results, a new “Moving Fit” method for processing of the trailed X-ray spectrograms was developed.