Intensity-dependent quasi-periodic oscillations in the X-ray flux of GX5-1

@article{Klis1985IntensitydependentQO,
  title={Intensity-dependent quasi-periodic oscillations in the X-ray flux of GX5-1},
  author={Marjolijn van der Klis and Fred A. Jansen and J. A. van Paradijs and Walter H. G. Lewin and Edward van den Heuvel and Joachim E. Tr{\"u}mper and M. Sztajno},
  journal={Nature},
  year={1985},
  volume={316},
  pages={225-230}
}
The X-ray flux of the bright galactic bulge source GX5-1 shows intensity-dependent quasi-periodic oscillations between ∼20 and ∼40 Hz, appearing as a broad peak in the power spectrum whose centroid frequency, width and integrated excess power strongly depend on the source intensity. The strength and steepness of low-frequency noise present in the power spectra below 15 Hz also depend on the source intensity. No evidence is found for coherent X-ray pulsations between 0.5 and 2,000 Hz. We discuss… 

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