Multi-wavelength Campaign on NGC 7469 VI. Photoionisation Modelling of the Emission Line Regions and the Warm Absorber
Résumé
Aims. We aim to investigate and characterise the photoionised X-ray emission line regions within the Seyfert 1 galaxy NGC 7469.Methods. We applied the photoionisation model, PION, within the spectral fitting code SPEX to analyse the 640 ks reflection grating spectrometer spectrum of NGC 7469 gathered during an XMM-Newton observing campaign in 2015.Results. We find the emission line region in NGC 7469 to be multiphased, consisting of two narrow components with ionisation parameters of log ξ = 0.4 and 1.6. A third, broad emission component, with a broadening velocity of vb ∼ 1400 km s−1 and an outflow velocity of vout ∼ −4500 km s−1 is required to fit the residuals in the O VII triplet at around 22 Å. Assuming a volume filling factor of 0.1, the lower distance limits of the narrow emission line region components are estimated for the first time at 2.6 and 2.5 pc from the central black hole, whereas the broad component has an estimated lower bound distance between 0.004 and 0.03 pc, depending on the assumed plasma parameters. The collisionally ionised plasma from the star burst region in NGC 7469 has a plasma temperature of 0.32 keV and an outflow velocity of −280 km s−1, which is consistent with previous results in this campaign. In addition, we model the photoionised plasma of the warm absorber (WA) in NGC 7469 and find that it consists of three photoionised phases with different values of ξ, NH and vout. The upper bound distances of these WA components are 1.9, 0.3, and 0.6 pc, respectively, consistent with archival results.Conclusion. The environment of NGC 7469 is a complex mix of plasma winds absorbing and emitting X-rays. We find the picture painted by our results can be attributed to line emitting plasma located at distances ranging from near the black hole to the torus and beyond the ionised outflows.Key words: X-rays: galaxies / galaxies: active / galaxies: Seyfert / galaxies: individual: NGC 7469 / techniques: spectroscopic
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