The X-ray disc/wind degeneracy in AGN

Parker, M. L.; Matzeu, G. A.; Matthews, James H.; Middleton, Matthew; Dauser, Thomas; Jiang, Jiachen; Joyce, Aoife

doi:10.1093/mnras/stac877

Cited by 23 publications

(11 citation statements)

References 77 publications

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“…By assumption, our analysis does not include any line-of-sight absorption by an ionised disc wind. Whilst there is no strong evidence for such a component (Oegerle et al 2000;Fang et al 2002;Mathur et al 2003), these wind signatures could, in principle, imitate several X-ray reflection signatureswe refer to Parker et al (2022) and Sim et al (2010Sim et al ( , 2008. The possible degeneracies on reflection parameters caused by the inclusion of such a disc wind are beyond the scope of this paper.…”

Section: Statistical Framework To Infer Merged Constraintsmentioning

confidence: 89%

Evidence for a moderate spin from X-ray reflection of the high-mass supermassive black hole in the cluster-hosted quasar H1821+643

Sisk-Reynés,

Reynolds,

Matthews

et al. 2022

Preprint

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We present an analysis of deep Chandra Low-Energy and High-Energy Transmission Grating archival observations of the extraordinarily luminous radio-quiet quasar H1821+643, hosted by a rich and massive cool-core cluster at redshift 𝑧 = 0.3. These datasets provide high-resolution spectra of the AGN at two epochs, free from contamination by the intracluster medium and from the effects of photon pile-up, providing a sensitive probe of the iron-𝐾 band. At both epochs, the spectrum is well described by a power-law continuum plus X-ray reflection from both the inner accretion disc and cold, slowly-moving distant matter. Adopting this framework, we proceed to examine the properties of the inner disc and the black hole spin. Using Markov chain Monte Carlo (MCMC) methods, we combine constraints from the two epochs assuming that the black hole spin, inner disc inclination, and inner disc iron abundance are invariant. The black hole spin is found to be modest, with a 90% credible range of 𝑎 * = 0.62 +0.22 −0.37 ; and, with a mass 𝑀 BH in the range log(𝑀 BH /𝑀 ) ∼ 9.2 − 10.5, this is the most massive black hole candidate for which a well-defined spin constraint has yet been obtained. The modest spin of this black hole supports previous suggestions that the most massive black holes may grow via incoherent or chaotic accretion and/or SMBH-SMBH mergers.

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Section: Statistical Framework To Infer Merged Constraintsmentioning

confidence: 89%

Evidence for a moderate spin from X-ray reflection of the high-mass supermassive black hole in the cluster-hosted quasar H1821+643

Sisk-Reynés,

Reynolds,

Matthews

et al. 2022

Preprint

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“…But future high-resolution X-ray observations, e.g. from Athena (Barcons et al 2017) and XRISM (XRISM Science Team 2020), might provide us with a unique opportunity to constrain any of the models for UGC 11763 by resolving multiple spectral components, e.g., from disc reflection (Parker et al 2022a) and warm absorption (Parker et al 2022b).…”

Section: Discussionmentioning

confidence: 99%

Comparing reflection and absorption models for the soft X-ray variability in the NLS1 AGN UGC 11763

Jiang

Gallo

Grupe

et al. 2022

Monthly Notices of the Royal Astronomical Society

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We present a spectral analysis of two XMM-Newton observations of the narrow-line Seyfert 1 galaxy UGC 11763. UGC 11763 shows very different soft X-ray spectral shapes in the two observations separated by 12 years. Three spectral models are considered to explain the multi-epoch X-ray variability of UGC 11763, one based on the relativistic disc reflection model, one based on multiple partially-covering absorbers combined with the warm corona model, and a hybrid model. In the first model, the X-ray variability of UGC 11763 is caused by the emission from a compact coronal region with a variable size. The resulting disc reflection component changes accordingly. A warm absorption model with a modest column density is required in this model too. In the partially-covering absorption scenario, the X-ray variability of UGC 11763 is caused by the variable covering factors of two absorbers located within a region of r < ≈100rg. Moreover, the temperature and strength of the warm corona have to change significantly too to explain the variable underlying soft X-ray emission. Lastly, we investigate the possibility of variable intrinsic power-law emission from the hot corona combined with variable absorption in UGC 11763 without changing the geometry of the corona in the third model. This hybrid model provides a slightly better fit than the partially-covering absorption model with improvements in fitting the iron emission band. Current CCD-resolution data cannot distinguish these spectral models for UGC 11763. Future high-resolution X-ray missions, e.g. Athena and XRISM, will test them by resolving different spectral components.

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“…11 , we show three simulated Athena /X-IFU resolution (i.e. 2 eV at 6.4 keV) spectra using the high-resolution disc-wind grid ( f32hires ; see Parker et al 2022 for details). f32hires was a MCRT generated table to match the microcalorimeter resolution data of XRISM /Resolve and Athena /X-IFU with a total of 10 000 Downloaded from https://academic.oup.com/mnras/article/515/4/6172/6653103 by University of Nottingham user on 13 September 2022 MNRAS 515, 6172-6190 (2022) energy bins (i.e.…”

Section: O B S E Rva T I O Na L Da Ta : F I T T I N G T H E P Ow E R ...mentioning

confidence: 99%

A new emulated Monte Carlo radiative transfer disc-wind model: X-Ray Accretion Disc-wind Emulator – xrade

Matzeu

Lieu

Costa

et al. 2022

Monthly Notices of the Royal Astronomical Society

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We present a new X-Ray Accretion Disk-wind Emulator (xrade) based on the 2.5D Monte Carlo radiative transfer code which provides a physically-motivated, self-consistent treatment of both absorption and emission from a disk-wind by computing the local ionization state and velocity field within the flow. xrade is then implemented through a process that combines X-ray tracing with supervised machine learning. We develop a novel emulation method consisting in training, validating, and testing the simulated disk-wind spectra into a purposely built artificial neural network. The trained emulator can generate a single synthetic spectrum for a particular parameter set in a fraction of a second, in contrast to the few hours required by a standard Monte Carlo radiative transfer pipeline. The emulator does not suffer from interpolation issues with multi-dimensional spaces that are typically faced by traditional X-ray fitting packages such as xspec. xrade will be suitable to a wide number of sources across the black-hole mass, ionizing luminosity, and accretion rate scales. As an example, we demonstrate the applicability of xrade to the physical interpretation of the X-ray spectra of the bright quasar PDS 456, which hosts the best-established accretion-disk wind observed to date. We anticipate that our emulation method will be an indispensable tool for the development of high-resolution theoretical models, with the necessary flexibility to be optimized for the next generation micro-calorimeters on board future missions, like XRISM/Resolve and Athena/X-IFU. This tool can also be implemented across a wide variety of X-ray spectral models and beyond.

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The X-ray disc/wind degeneracy in AGN

Cited by 23 publications

References 77 publications

Evidence for a moderate spin from X-ray reflection of the high-mass supermassive black hole in the cluster-hosted quasar H1821+643

Evidence for a moderate spin from X-ray reflection of the high-mass supermassive black hole in the cluster-hosted quasar H1821+643

Comparing reflection and absorption models for the soft X-ray variability in the NLS1 AGN UGC 11763

A new emulated Monte Carlo radiative transfer disc-wind model: X-Ray Accretion Disc-wind Emulator – xrade

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