ABSTRACT Context: Recent studies of the X-ray spectrum of the quasar 3C 273, analyzing both BeppoSAX data and XMM-Newton data, have shown that, depending on the state of the source, Seyfert-like spectral features, including a significant soft excess, can be detected superimposed on the generally overwhelming beamed non-thermal emission (“jet” component). Aims: In order to explain the Seyfert-like component and the soft excess suggested by the X-ray spectrum analysis, we apply to 3C 273 a recently developed model for non-thermal emission of X-rays from AGN disk coronae, originally intended for the explanation of Seyfert type X-ray emission. Methods: We perform an analysis of BeppoSAX data at different epochs, fitting the spectrum with a composition of a beamed “jet” component and our coronal model with a reflected component and an iron emission line. Results: We obtained reasonable fits of BeppoSAX spectra at different epochs by changing the relative weight of our emission model and of the jet power-law component. We find that in all these cases the low energy ( ≤ 2 keV) part of the X-ray spectrum is accounted for by our Seyfert-like model; we also verify the existence of a positive correlation between the Seyfert-like component 2-10 keV flux and the 0.2-2 keV flux of the so-called soft excess. Conclusions: The results outlined above confirm the plausibility of our non-thermal flare-like coronal model as a possible interpretation of Seyfert-like emission in AGNs. We can conclude that the interpretation of the Seyfert-like component in terms of our non-thermal corona model is offering, as a natural result, a description of the soft excess origin, which is still the subject of lively debate.

A possible interpretation of the Seyfert-like component in 3C 273 X-ray spectrum / P. PIETRINI; G. Torricelli-Ciamponi. - In: ASTRONOMY & ASTROPHYSICS. - ISSN 0004-6361. - STAMPA. - 479:(2008), pp. 365-376. [10.1051/0004-6361:20077597]

A possible interpretation of the Seyfert-like component in 3C 273 X-ray spectrum

PIETRINI, PAOLA;
2008

Abstract

ABSTRACT Context: Recent studies of the X-ray spectrum of the quasar 3C 273, analyzing both BeppoSAX data and XMM-Newton data, have shown that, depending on the state of the source, Seyfert-like spectral features, including a significant soft excess, can be detected superimposed on the generally overwhelming beamed non-thermal emission (“jet” component). Aims: In order to explain the Seyfert-like component and the soft excess suggested by the X-ray spectrum analysis, we apply to 3C 273 a recently developed model for non-thermal emission of X-rays from AGN disk coronae, originally intended for the explanation of Seyfert type X-ray emission. Methods: We perform an analysis of BeppoSAX data at different epochs, fitting the spectrum with a composition of a beamed “jet” component and our coronal model with a reflected component and an iron emission line. Results: We obtained reasonable fits of BeppoSAX spectra at different epochs by changing the relative weight of our emission model and of the jet power-law component. We find that in all these cases the low energy ( ≤ 2 keV) part of the X-ray spectrum is accounted for by our Seyfert-like model; we also verify the existence of a positive correlation between the Seyfert-like component 2-10 keV flux and the 0.2-2 keV flux of the so-called soft excess. Conclusions: The results outlined above confirm the plausibility of our non-thermal flare-like coronal model as a possible interpretation of Seyfert-like emission in AGNs. We can conclude that the interpretation of the Seyfert-like component in terms of our non-thermal corona model is offering, as a natural result, a description of the soft excess origin, which is still the subject of lively debate.
2008
479
365
376
P. PIETRINI; G. Torricelli-Ciamponi
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Utilizza questo identificatore per citare o creare un link a questa risorsa: https://hdl.handle.net/2158/333414
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