Middei, R;
Cappi, M;
Petrucci, P-O;
Ursini, F;
Arav, N;
Behar, E;
Branduardi Raymont, G;
... Ponti, G; + view all
(2018)
Multi-wavelength campaign on NGC 7469 IV. The broad-band X-ray spectrum.
Astronomy and Astrophysics
, 615
, Article A163. 10.1051/0004-6361/201832726.
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Abstract
We conducted a multi-wavelength six-month campaign to observe the Seyfert galaxy NGC 7469, using the space-based observatories HST, Swift, XMM-Newton and NuSTAR. Here we report the results of the spectral analysis of the 7 simultaneous XMM-Newton and NuSTAR observations. The sources shows significant flux variability within each observation, but the average flux is less variable among the different pointings of our campaign. Our spectral analysis reveals a prominent narrow neutral Fe kα emission line in all the spectra, with weaker contributions from Fe Kβ, neutral Ni Kα and ionised iron. We find no evidence for variability or relativistic effects acting on the emission lines, which indicates that they originate from distant material. Analysing jointly XMM-Newton and NuSTAR data a constant photon index is found (Γ=1.78 ± 0.02), together with a high energy cut-off Ecut = 170+60 −40 keV. Adopting a self-consistent Comptonization model, these values correspond to an average coronal electron temperature of kT=45+15 −12 keV and, assuming a spherical geometry, an optical depth τ = 2.6 ± 0.9. The reflection component is consistent with being constant, with a reflection fraction in the range R = 0.3−0.6. A prominent soft excess dominates the spectra below 4 keV. This is best fit with a second Comptonization component, arising from a “warm corona” with an average kT = 0.67 ± 0.03 keV and a corresponding optical depth τ = 9.2 ± 0.2.
| Type: | Article |
|---|---|
| Title: | Multi-wavelength campaign on NGC 7469 IV. The broad-band X-ray spectrum |
| Open access status: | An open access version is available from UCL Discovery |
| DOI: | 10.1051/0004-6361/201832726 |
| Publisher version: | https://doi.org/10.1051/0004-6361/201832726 |
| Language: | English |
| Additional information: | This version is the author accepted manuscript. For information on re-use, please refer to the publisher’s terms and conditions. |
| Keywords: | galaxies:active – quasars:general – X-rays:galaxies |
| UCL classification: | UCL UCL > Provost and Vice Provost Offices > UCL BEAMS UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences > Dept of Space and Climate Physics |
| URI: | https://discovery.ucl.ac.uk/id/eprint/10045789 |
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