Multi-wavelength campaign on NGC 7469

VI. Photoionisation modelling of the emission line regions and the warm absorber

¹ Mullard Space Science Laboratory, University College London, Holmbury St. Mary Dorking, Surrey RH5 6NT, UK
e-mail: sam.waters.17@ucl.ac.uk
² SRON Netherlands Institute for Space Research, Sorbonnelaan 2, 3584 CA Utrecht, The Netherlands
³ Department of Physics, Technion-Israel Institute of Technology, 32000 Haifa, Israel
⁴ Leiden Observatory, Leiden University, PO Box 9513, 2300 RA Leiden, The Netherlands
⁵ Department of Physics, Virginia Tech, Blacksburg, VA 24061, USA
⁶ Dipartimento di Matematica e Fisica, Università degli Studi Roma Tre, Via della Vasca Navale 84, 00146 Roma, Italy
⁷ European Space Astronomy Centre, PO Box 78, 28691 Villanueva de la Caada, Madrid, Spain
⁸ Italian Space Agency (ASI), Via del Politecnico snc, 00133 Roma, Italy
⁹ School of Physics and Astronomy and Wise Observatory, Tel Aviv University, Tel Aviv 69978, Israel
¹⁰ Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218, USA
¹¹ Nicolaus Copernicus Astronomical Center, Polish Academy of Sciences, Bartycka 18, 00-716 Warsaw, Poland
¹² Department of Physics, University of Strathclyde, Glasgow G4 0NG, UK
¹³ Univ. Grenoble Alpes, IPAG, 38000 Grenoble, France
¹⁴ CNRS, IPAG, 38000 Grenoble, France
¹⁵ Max-Planck-Institut für Extraterrestrische Physik, Giessenbachstrasse, 85748 Garching, Germany

Received: 29 April 2019
Accepted: 3 July 2019

Abstract

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 v_b ∼ 1400 km s⁻¹ and an outflow velocity of v_out ∼ −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, N_H and v_out. 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.