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A full characterization of the supermassive black hole in IRAS 09149–6206

Walton, D. J. and Alston, W. N. and Kosec, P. and Fabian, A. C. and Gallo, L. C. and García, J. A. and Miller, J. M. and Nardini, E. and Reynolds, M. T. and Ricci, C. and Stern, D. and Dauser, T. and Harrison, F. A. and Reynolds, C. S. (2020) A full characterization of the supermassive black hole in IRAS 09149–6206. Monthly Notices of the Royal Astronomical Society, 499 (1). pp. 1480-1498. ISSN 0035-8711.

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We present new broad-band X-ray observations of the type-I Seyfert galaxy IRAS 09149–6206, taken in 2018 with XMM–Newton, NuSTAR, and Swift. The source is highly complex, showing a classic ‘warm’ X-ray absorber, additional absorption from highly ionized iron, strong relativistic reflection from the innermost accretion disc and further reprocessing by more distant material. By combining X-ray timing and spectroscopy, we have been able to fully characterize the supermassive black hole in this system, constraining both its mass and – for the first time – its spin. The mass is primarily determined by X-ray timing constraints on the break frequency seen in the power spectrum, and is found to be log [M_(BH)/M_⊙] = 8.0 ± 0.6 (1σ uncertainties). This is in good agreement with previous estimates based on the H α and H β line widths, and implies that IRAS 09149–6206 is radiating at close to (but still below) its Eddington luminosity. The spin is constrained via detailed modelling of the relativistic reflection, and is found to be a∗ = 0.94^(+0.02)_(−0.07) (90 per cent confidence), adding IRAS 09149–6206 to the growing list of radio-quiet active galactic nuclei (AGNs) that host rapidly rotating black holes. The outflow velocities of the various absorption components are all relatively modest (v_(out) ≲ 0.03c), implying these are unlikely to drive significant galaxy-scale AGN feedback.

Item Type:Article
Related URLs:
URLURL TypeDescription Paper ItemESA XMM–Newton Science Archive ItemNASA HEASARC archive
Walton, D. J.0000-0001-5819-3552
Alston, W. N.0000-0003-2658-6559
Fabian, A. C.0000-0002-9378-4072
García, J. A.0000-0003-3828-2448
Nardini, E.0000-0001-9226-8992
Ricci, C.0000-0001-5231-2645
Stern, D.0000-0003-2686-9241
Dauser, T.0000-0003-4583-9048
Harrison, F. A.0000-0003-2992-8024
Reynolds, C. S.0000-0002-1510-4860
Additional Information:© 2020 The Author(s). Published by Oxford University Press on behalf of the Royal Astronomical Society. This article is published and distributed under the terms of the Oxford University Press, Standard Journals Publication Model ( Accepted 2020 September 17. Received 2020 September 15; in original form 2020 June 7. Published: 01 October 2020. The authors would like to thank the reviewer for the feedback provided, which helped improve the final version of the manuscript. DJW acknowledges support from the Science and Technology Facilities Council (STFC) via an Ernest Rutherford Fellowship, and PK acknowledges support from an STFC studentship. JAG acknowledges support from NASA grants 80NSSC19K1020 and 80NSSC19K0586, and from the Alexander von Humboldt Foundation. EN acknowledges financial contribution from the agreement ASI-INAF n.2017-14-H.0 and partial support from the EU Horizon 2020 Marie Skłodowska-Curie grant agreement no. 664931. CR acknowledges support from the Fondecyt Iniciacion grant 11190831. CSR thanks STFC for support under the New Applicant grant ST/R000867/1, and the European Research Council for support under the European Union’s Horizon 2020 research and innovation programme (grant 834203). This research has made use of data obtained with NuSTAR, a project led by Caltech, funded by NASA and managed by NASA Jet Propulsion Laboratory (JPL), and has utilized the NUSTARDAS software package, jointly developed by the Space Science Data Centre (SSDC; Italy) and Caltech (USA). This research has also made use of data obtained with XMM–Newton, an ESA science mission with instruments and contributions directly funded by ESA Member States, as well as public data from the Swift data archive. This work has made use of the CORNER package (Foreman-Mackey 2016) for data visualization. Data Availability: The data underlying this article are all publicly available from ESA’s XMM–Newton Science Archive ( and NASA’s HEASARC archive (
Group:Astronomy Department
Funding AgencyGrant Number
Science and Technology Facilities Council (STFC)ST/R000867/1
Alexander von Humboldt FoundationUNSPECIFIED
Agenzia Spaziale Italiana (ASI)2017-14-H.0
Marie Curie Fellowship664931
Fondo Nacional de Desarrollo Científico y Tecnológico (FONDECYT)11190831
European Research Council (ERC)834203
Subject Keywords:black hole physics – galaxies: active – X-rays: individual (IRAS 09149–6206)
Issue or Number:1
Record Number:CaltechAUTHORS:20201214-104307005
Persistent URL:
Official Citation:D J Walton, W N Alston, P Kosec, A C Fabian, L C Gallo, J A Garcia, J M Miller, E Nardini, M T Reynolds, C Ricci, D Stern, T Dauser, F A Harrison, C S Reynolds, A full characterization of the supermassive black hole in IRAS 09149–6206, Monthly Notices of the Royal Astronomical Society, Volume 499, Issue 1, November 2020, Pages 1480–1498,
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:107065
Deposited By: Tony Diaz
Deposited On:14 Dec 2020 22:11
Last Modified:14 Dec 2020 22:11

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