A long term study of AGN X-ray variability. Structure function analysis on a ROSAT-XMM quasar sample

  title={A long term study of AGN X-ray variability. Structure function analysis on a ROSAT-XMM quasar sample},
  author={Riccardo Middei and Fausto Vagnetti and Stefano Bianchi and Fabio La Franca and Maurizio Paolillo and Francesco Ursini},
  journal={Astronomy and Astrophysics},
Variability in the X-rays is a key ingredient in understanding and unveiling active galactic nuclei (AGN) properties. In this band flux variations occur on short time scales (hours) as well as on larger times scales. While short time scale variability is often investigated in single source studies, only few works are able to explore flux variation on very long time scales.This work provides a statistical analysis of the AGN long term X-ray variability. We study variability on the largest… Expand

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