152 citations · 2.4k across the 122 of their papers we have counts for
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Ensemble X-ray variability of Active Galactic Nuclei. II. Excess Variance and updated Structure Function
F. Vagnetti, R. Middei, M. Antonucci +2
Most investigations of the X-ray variability of active galactic nuclei (AGN) have been concentrated on the detailed analyses of individual, nearby sources. A relatively small numbe…
A new approach to the variability characterization of active galactic nuclei
Riccardo Middei, Fausto Vagnetti, Marco Antonucci +1
The normalized excess variance is a popular method used by many authors to estimate the variability of active galactic nuclei (AGNs), especially in the X-ray band. We show that thi…
Ensemble spectral variability study of Active Galactic Nuclei from the XMM-Newton serendipitous source catalogue
Roberto Serafinelli, Fausto Vagnetti, Riccardo Middei
The variability of the X-ray spectra of active galactic nuclei (AGN) usually includes a change of the spectral slope. This has been investigated for a small sample of local AGNs by…