2004/09/17 by M. Guainazzi, E. Jiménez‐Bailón, Guainazzi, M. +4
Physics and Astronomy · #Astrophysical Phenomena and Observations #Astrophysics (astro-ph) #FOS: Physical sciences #Galaxies: Formation, Evolution, Phenomena #Pulsars and Gravitational Waves Research #astro-ph
paper · pdf · doi:10.48550/arxiv.astro-ph/0409438
4 pages, 4 figures, contribution to the proceedings of the conference: "AGN Variability from X-rays to Radio Waves", C.M.Gaskell, I.M.McHardy, B.M.Peterson, S.G.Sergeev eds., ASP
arxiv created 2004/09/17 · openalex publication_date 2004/09/17 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
This paper presents preliminary results of a systematic study on the X-ray spectral variability of PG quasars with XMM-Newton. We concentrate on those objects, whose X-ray spectra are well fit in the framework of the ``double Comptonization'' model. On short (<1000 seconds) timescales, variability between the soft (E<2 keV) and the hard (E>2 keV) bands is uncorrelated. In the two objects, for which observations at different epochs are available, spectral variability in the soft X-ray regime is unveiled. Its timescale is constrained in the range between ~1 week and ~1 year.