Towards precision measurements of accreting black holes using X-ray reflection spectroscopy

C Bambi, LW Brenneman, T Dauser, JA Garcia… - Space Science …, 2021 - Springer
Relativistic reflection features are commonly observed in the X-ray spectra of accreting black
holes. In the presence of high quality data and with the correct astrophysical model, X-ray …

Explaining changing-look AGN with state transition triggered by rapid mass accretion rate drop

H Noda, C Done - Monthly Notices of the Royal Astronomical …, 2018 - academic.oup.com
We model the broad-band (optical/UV and X-ray) continuum spectrum of the 'changing-
look'active galactic nucleus (AGN) Mrk 1018, as it fades from Seyfert 1 to 1.9 in∼ 8 years …

A physical model of the broad-band continuum of AGN and its implications for the UV/X relation and optical variability

A Kubota, C Done - Monthly Notices of the Royal Astronomical …, 2018 - academic.oup.com
We develop a new spectral model for the broad-band spectral energy distribution (SED) of
active galactic nuclei (AGN). This includes an outer standard disc, an inner warm …

Radiation spectra of warm and optically thick coronae in AGNs

PO Petrucci, D Gronkiewicz, A Rozanska… - Astronomy & …, 2020 - aanda.org
A soft X-ray excess above the 2–10 keV power-law extrapolation is generally observed in
the X-ray spectra of active galactic nuclei. The origin of this excess is still not well …

Implications of the warm corona and relativistic reflection models for the soft excess in mrk 509

JA García, E Kara, D Walton, T Beuchert… - The Astrophysical …, 2019 - iopscience.iop.org
We present the analysis of the first Nuclear Spectroscopic Telescope Array observations (∼
220 ks), simultaneous with the last Suzaku observations (∼ 50 ks), of the active galactic …

UV/Optical disk thermal reverberation in active galactic nuclei: an in-depth study with an analytic prescription for time-lag spectra

ES Kammoun, M Dovčiak, IE Papadakis… - The Astrophysical …, 2021 - iopscience.iop.org
Several active galactic nuclei show correlated variations in the UV/optical range, with time
delays increasing at longer wavelengths. Thermal reprocessing of the X-rays illuminating …

A NuSTAR census of coronal parameters in Seyfert galaxies

A Tortosa, S Bianchi, A Marinucci, G Matt… - Astronomy & …, 2018 - aanda.org
Context. We discuss the results of the hot corona parameters of active galactic nuclei (AGN)
that have been recently measured with NuSTAR. The values taken from the literature of a …

Probing the face-on disc-corona system of the bare AGN Mrk 110 from UV to hard X-rays: A moderate changing-state AGN?

D Porquet, S Hagen, N Grosso, A Lobban… - Astronomy & …, 2024 - aanda.org
Context. The X-ray broadband spectra of the bare active galactic nucleus (AGN) Mrk 110,
obtained by simultaneous XMM-Newton and NuSTAR observations performed in November …

Changing-look event in NGC 3516: continuum or obscuration variability?

M Mehdipour, GA Kriss, LW Brenneman… - The Astrophysical …, 2022 - iopscience.iop.org
The Seyfert-1 galaxy NGC 3516 has undergone major spectral changes in recent years. In
2017 we obtained Chandra, NuSTAR, and Swift observations during its new low-flux state …

Estimating black hole spin from AGN SED fitting: the impact of general-relativistic ray tracing

S Hagen, C Done - Monthly Notices of the Royal Astronomical …, 2023 - academic.oup.com
Accretion disc model fitting to optical/UV quasar spectra requires that the highest mass black
holes have the highest spin, with implications on the hierarchical growth of supermassive …