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The article titled "Correction to: Characterizing X-ray, UV, and optical variability in NGC 6814 using high-cadence Swift observations from a 2022 monitoring campaign" published in the Monthly Notices of the Royal Astronomical Society discusses a correction to a previous study on NGC 6814. The authors discovered that an outdated Calibration Database (CALDB) version was used in the original study, leading to significantly larger UV flux densities. The updated results show that the intrinsic AGN variability spectrum aligns with a standard accretion disc, except in the U band. The authors also discuss the inter-band continuum lags and suggest that a significant contribution from diffuse continuum emission in NGC 6814 may explain the observed discrepancies. The corrected data is publicly available through the NASA HEASARC Archive and Swift observatory websites. [Extracted from the article]

We present the first results of a high-cadence Swift monitoring campaign (3–4 visits per day for 75 d) of the type 1.5 Seyfert galaxy NGC 6814 characterizing its variability throughout the X-ray and ultraviolet (UV)/optical wavebands. Structure function analysis reveals an X-ray power law (⁠|$\alpha =0.5^{+0.2}_{-0.1}$|⁠) that is significantly flatter than the one measured in the UV/optical bands (〈α〉 ≈ 1.5), suggesting different physical mechanisms driving the observed variability in each emission region. The structure function break-time is consistent across the UV/optical bands (〈τ〉 ≈ 2.3 d), suggesting a very compact emission region in the disc. Correlated short time-scale variability measured through cross-correlation analysis finds a lag–wavelength spectrum that is inconsistent with a standard disc reprocessing scenario (τ ∝ λ4/3) due to significant flattening in the optical wavebands. Flux–flux analysis finds an extremely blue active galactic nucleus (AGN) spectral component (F ν ∝ λ−0.85) that does not follow a standard accretion disc profile (F ν ∝ λ−1/3). While extreme outer disc truncation (R out = 202 ± 5 rg) at a standard accretion rate (⁠|$\dot{m}_{\mathrm{Edd}}=0.0255\pm 0.0006$|⁠) may explain the shape of the AGN spectral component, the lag–wavelength spectrum requires more modest truncation (⁠|$R_{\mathrm{out}}=1382^{+398}_{-404}\,r_g$|⁠) at an extreme accretion rate (⁠|$\dot{m}_{\mathrm{Edd}}=1.3^{+2.1}_{-0.9}$|⁠). No combination of parameters can simultaneously explain both results in a self-consistent way. Our results point towards the possibility of a non-standard disc geometry in NGC 6814. [ABSTRACT FROM AUTHOR]

Eclipsing of the X-ray emitting region in active galactic nuclei (AGN) is a potentially powerful probe to examine the AGN environment and absorber properties. Here, we study the eclipse data from the 2016 XMM–Newton observation of NGC 6814 using a colour–colour analysis. Colours (i.e. hardness ratios) can provide the advantage of better time resolution over spectral analysis alone. Colour–colour grids are constructed to examine the effects of different parameters on the observed spectral variability during the eclipse. Consistent with previous spectral analysis, the variations are dominated by changes in the column density and covering fraction of the absorber. However, during maximum eclipse the behaviour of the absorber changes. Just after ingress, the eclipse is described by changes in column density and covering fraction, but prior to egress, the variations are dominated by changes in column density alone. Simulations are carried out to consider possible absorber geometries that might produce this behaviour. The behaviour is inconsistent with a single homogeneous cloud, but simulations suggest that multiple clouds, perhaps embedded in a highly ionized halo, could reproduce the results. In addition, we determine the orbital covering factor (fraction of orbital path-length) based on evidence of several eclipses in the 2016; 64-d Swift light curve. We estimate that ∼2–4 per cent of the orbit is covered by obscuring clouds and that the distribution of clouds is not isotropic. [ABSTRACT FROM AUTHOR]

In this work, we examine the application of the wavelet transform to the X-ray timing analyses of active galactic nuclei (AGN) and quasi-periodic eruption sources (QPEs). Several scenarios are simulated to test the effectiveness of the wavelet analysis to stationary and non-stationary data. We find that the power spectral density (PSD) slope and the nature of the periodic signal can influence the ability to identify important features in the wavelet power spectrum. In general, weak and transient features can be discerned, which make the wavelet spectrum an important tool in examining AGN light curves. We carried out a wavelet analysis to four unique objects: Ark 120, IRAS 13224-3809, RE J1034+396, and the QPE GSN 069. The well-known quasi-periodic oscillation (QPO) in RE J1034 + 396 is significantly detected in the wavelet power spectrum. In IRAS 13224-3809, significant transient features appear during a flare at frequencies coincident with previously detected reverberation signals. Finally, the wavelet power spectrum of the QPE GSN 069 significantly reveals four persistent signals that exhibit a 3:2 ratio in oscillation frequencies, consistent with high-frequency QPOs in stellar mass X-ray binaries, but we cannot rule out the possibility this is an artefact of the calculation. [ABSTRACT FROM AUTHOR]

The project MOMO (Multiwavelength Observations and Modelling of OJ 287) was set up to test predictions of binary supermassive black hole (SMBH) scenarios and to understand disc–jet physics of the blazar OJ 287. After a correction, the precessing binary (PB) SMBH model predicted the next main outburst of OJ 287 in 2022 October, making the outburst well observable and the model testable. We have densely covered this period in our ongoing multifrequency radio, optical, ultraviolet (UV), and X-ray monitoring. The predicted outburst was not detected. Instead, OJ 287 was at low optical–UV emission levels, declining further into November. The predicted thermal bremsstrahlung spectrum was not observed either, at any epoch. Further, applying scaling relations, we estimate an SMBH mass of OJ 287 of 108 M⊙. The latest in a sequence of deep low states that recur every 1–2 yr is used to determine an upper limit on the Eddington ratio and on the accretion-disc luminosity. This limit is at least a factor of 10 lower than required by the PB model with its massive primary SMBH of >1010 M⊙. All these results favour alternative binary SMBH models of OJ 287 that require neither strong orbital precession nor a very large mass of the primary SMBH. [ABSTRACT FROM AUTHOR]

The narrow-line Seyfert 1 galaxy |$\rm I\,\,Zwicky\, 1$| shows a unique and complex system of ionized gas in outflow, which consists of an ultra-fast wind and a two-component warm absorber. In the last two decades, XMM–Newton monitored the source multiple times enabling the study of the long-term variability of the various outflows. Plasma in photoionization equilibrium with the ionizing source responds and varies accordingly to any change of the ionizing luminosity. However, detailed modelling of the past Reflection Grating Spectrometer (RGS) data has shown no correlation between the plasma ionization state and the ionizing continuum, revealing a complex long-term variability of the multiphase warm absorber. Here, we present a new observation of |$\rm I\,\,Zwicky\, 1$| by XMM–Newton taken in early 2020 characterized by a lower X-ray flux state. The soft X-ray spectrum from the RGS reveals the two components of the warm absorber with log ξ ∼ −1.0 and log ξ ∼ 1.7. Comparing our results with the previous observations, the ionization state of the two absorbing gas components is continuously changing, following the same unpredictable behaviour. The new results strengthen the scenario in which the ionization state of the warm absorber is driven by the density of the gas rather than the ionizing luminosity. In particular, the presence of a radiation driven, inhomogeneous clumpy outflow may explain both the variability in ionization throughout the years and the line-locked N  v system observed in the ultraviolet band. Finally, the EPIC-pn spectrum reveals an ultra-fast wind with an outflow velocity of ∼0.26 c and ionization parameter of log ξ ∼ 3.8. [ABSTRACT FROM AUTHOR]

Understanding whether and when the accretion disc extends down to the innermost stable circular orbit is important since it is the fundamental assumption behind measuring black hole spin. Here, we examine the 2013 and 2018 NuSTAR and Swift data (⁠|$0.5\!-\!50{\rm \, keV}$|⁠) of the narrow-line Seyfert 1 galaxy, WKK 4438. The X-ray emission can be fitted well with models depicting a corona and blurred reflection originating from a disc around a low-spin (a * ≈ 0) black hole. However, such models result in unconventional values for some of the parameters (e.g. inverted emissivity profile and high coronal height). Alternatively, equally good fits can be achieved if the disc is truncated at |$\sim 10{\, r_{\rm g}}$| and the black hole is spinning at the Thorne limit (a * = 0.998). In these cases, the model parameters are consistent with the interpretation that the corona is centrally located close to the black hole and illuminating the disc at a larger distance. [ABSTRACT FROM AUTHOR]

We report results from our ongoing project MOMO (Multiwavelength Observations and Modelling of OJ 287). In this latest publication of a sequence, we combine our Swift UVOT–XRT and Effelsberg radio data (2.6–44 GHz) between 2019 and 2022.04 with public SMA data and gamma-ray data from the Fermi satellite. The observational epoch covers OJ 287 in a high state of activity from radio to X-rays. The epoch also covers two major events predicted by the binary supermassive black hole (SMBH) model of OJ 287. Spectral and timing analyses clearly establish: a new UV–optical minimum state in 2021 December at an epoch where the secondary SMBH is predicted to cross the disc surrounding the primary SMBH; an overall low level of gamma-ray activity in comparison to pre-2017 epochs; the presence of a remarkable, long-lasting UV–optical flare event of intermediate amplitude in 2020–2021; a high level of activity in the radio band with multiple flares; and particularly a bright, ongoing radio flare peaking in 2021 November that may be associated with a gamma-ray flare, the strongest in 6 yr. Several explanations for the UV–optical minimum state are explored, including the possibility that a secondary SMBH launches a temporary jet, but the observations are best explained by variability associated with the main jet. [ABSTRACT FROM AUTHOR]

We report on X-ray flares that were observed from the active galactic nucleus I Zwicky 1 (I Zw 1) in 2020 January by the NuSTAR and XMM-Newton observatories. The X-ray spectrum is well-described by a model comprised of the continuum emission from the corona and its reflection from the accretion disc around a rapidly spinning (a > 0.94) black hole. In order to model the broadband spectrum, it is necessary to account for the variation in ionization across the disc. Analysis of the X-ray spectrum in time periods before, during and after the flares reveals the underlying changes to the corona associated with the flaring. During the flares, the reflection fraction drops significantly, consistent with the acceleration of the corona away from the accretion disc. We find the first evidence that during the X-ray flares, the temperature drops from |$140_{-20}^{+100}$|  keV before to |$45_{-9}^{+40}$|  keV during the flares. The profile of the iron K line reveals the emissivity profile of the accretion disc, showing it to be illuminated by a compact corona extending no more than |$7_{-2}^{+4}$|   r g over the disc before the flares, but with tentative evidence that the corona expands as it is accelerated during the flares. Once the flares subsided, the corona had collapsed to a radius of |$6_{-2}^{+2}$|   r g. The rapid time-scale of the flares suggests that they arise within the black hole magnetosphere rather than in the accretion disc, and the variation of the corona is consistent with the continuum arising from the Comptonization of seed photons from the disc. [ABSTRACT FROM AUTHOR]

A sample of 22 narrow-line type 1 Seyfert (NLS1) and 47 broad-line type 1 Seyfert (BLS1) galaxies observed with Suzaku is used to examine the Fe K-band properties of each group. Three different models are used to examine the presence of: narrow neutral Fe K α line at |$6.4{\rm \, keV}$| and ionized Fe  xxv and Fe  xxvi emission lines (model A); a broad emission feature at around |$6{-}7{\rm \, keV}$| (model B); and an absorption edge at |${\sim}7.1{\rm \, keV}$| (model C). In all three models, the neutral Fe K α line is weaker (lower luminosity and equivalent width) in NLS1s than in BLS1s. Model (B) also finds a more significant broad component (larger equivalent width) in NLS1s than in BLS1s. The feature does not appear to be an artifact of steeper spectra in NLS1s, but rather an intrinsic property of these sources. From model (C), the optical depth of the absorption edge appears comparable between the two samples. When comparing the absorption with the emission line properties, NLS1s seem to exhibit a lower ratio of emission-to-absorption of iron than BLS1s, and have a lower value than expected based on the fluorescence yield. The observed differences may arise from different torus geometries (e.g. larger opening angle in NLS1s), and/or additional sources of Fe K emission and absorption in NLS1s beyond pure fluorescence (e.g. originating in the disc and broad-line region). [ABSTRACT FROM AUTHOR]

We present the first high signal-to-noise broad-band X-ray spectrum of the radio-quiet type-2 Seyfert ESO 033-G002, combining data from XMM–Newton and NuSTAR. The nuclear X-ray spectrum is complex, showing evidence for both neutral and ionized absorption, as well as reflection from both the accretion disc and more distant material, but our broad-band coverage allows us to disentangle all of these different components. The total neutral column during this epoch is N H ∼ (5−6) × 1022  |$\rm \, cm^{-2}$|⁠ , consistent with the optical classification of ESO 033-G002 as a type-2 Seyfert but not so large as to prevent us from robustly determining the properties of the innermost accretion flow. The ionized absorption – dominated by lines from Fe  xxv and Fe  xxvi – reveals a moderately rapid outflow (v out ∼ 5400  |$\rm \, km~s^{-1}$|⁠) which has a column comparable to the neutral absorption. We find the disc reflection from the innermost regions to be extreme, with a reflection fraction of R frac ∼ 5. This requires strong gravitational lightbending and, in turn, both an extremely compact corona (within ∼2  R G of the black hole) and a rapidly rotating black hole (a * > 0.96). Despite this tight size constraint, with a temperature of kT e = 40–70 keV the X-ray corona in ESO 033-G002 appears similar to other active galactic nucle in terms of its placement in the compactness–temperature plane, consistent with sitting close to the limit determined by runaway pair production. Finally, combining X-ray spectroscopy, timing, and updated optical spectroscopy, we also estimate the mass of the black hole to be log[ M BH/M⊙] ∼ 7.0–7.5. [ABSTRACT FROM AUTHOR]

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 ≲ 0.03 c), implying these are unlikely to drive significant galaxy-scale AGN feedback. [ABSTRACT FROM AUTHOR]

Multiwavelength monitoring of Mrk 335 with Swift between 2007 and 2019 are used to construct annual spectral energy distributions (SEDs) and track year-to-year changes. Non-contemporaneous archival data prior to 2007 are used to build a bright state SED. In this work, the changes are examined and quantified to build the foundation for future SED modelling. The yearly SEDs trace a downward trend on the average, with the X-ray portion varying significantly and acquiring further lower values in the past two years when compared to the optical/UV portion of SED. The bolometric Eddington ratios derived using optical/UV to X-ray SEDs and the calculated X-ray luminosities show a gradual decrease over the monitoring period. Changes in the parameters over time are examined. Principal component analysis suggests that the primary variability is in the X-ray properties of Mrk 335. When looking at the broader picture of Mrk 335 and its behaviour, the X-rays, accounting most of the variability in the 13-yr data, are possibly driven by physical processes related to the corona or absorption whereas the modest optical–UV variations suggest their origin within the accretion disc. These results are consistent with the previous interpretation of Mrk 335 using the timing analyses on the monitoring data and spectral modelling of deep observations. [ABSTRACT FROM AUTHOR]

A sample of narrow-line Seyfert 1 (NLS1) and broad-line Seyfert 1 (BLS1) galaxies observed with Suzaku is presented. The final sample consists of 22 NLS1s and 47 BLS1s, for a total of 69 active galactic nuclei (AGNs) that are all at low redshift (z < 0.5) and exhibit low host-galaxy column densities (<1022 |${\rm cm}^{-2}\,$|⁠). The average spectrum for each object is fit with a toy model to characterize important parameters, including the photon index, soft excess, Compton hump (or hard excess), narrow iron line strength, luminosity, and X-ray Eddington ratio (L x/ L Edd). We confirm previous findings that NLS1s have steeper power laws and higher X-ray Eddington ratios, but also find that NLS1 galaxies have stronger soft and hard excesses than their BLS1 counterparts. Studying the correlations between parameters shows that the soft and hard excesses are correlated for NLS1 galaxies, while no such correlation is observed for BLS1s. Performing a principal component analysis (PCA) on the measured X-ray parameters shows that while the X-ray Eddington ratio is the main source of variations within our sample (PC1), variations in the soft and hard excesses form the second principal component (PC2) and it is dominated by the NLS1s. The correlation between the soft and hard excesses in NLS1 galaxies may suggest a common origin for the two components, such as a blurred reflection model. The presented Suzaku sample of Seyfert 1 galaxies is a useful tool for the analysis of the X-ray properties of AGNs, and for the study of the soft and hard excesses observed in AGNs. [ABSTRACT FROM AUTHOR]

We present results of temporal and spectral analyses on four XMM–Newton  EPIC pn observations of IRAS 17020+4544, a narrow-line Seyfert 1 galaxy with evidence of a radio jet. Analysis of the light curves reveals that this radio-loud source does not behave like the bulk population of its radio-quiet counterparts. A trend of spectral hardening with increased flux is found. Variability is found to increase with energy, though it decreases as the spectrum hardens. The first 40 ks of the most recent observation behave uniquely among the epochs, exhibiting a softer spectral state than at any other time. Possible non-stationarity at low energies is found, with no such effect present at higher energies, suggesting at least two distinct spectral components. A reverberation signature is confirmed, with the lag-frequency, lag-energy, and covariance spectra changing significantly during the soft-state epoch. The temporal analysis suggests a variable power law in the presence of a reflection component, thus motivating such a fit for the 0.3−10 keV EPIC pn spectra from all epochs. We find an acceptable spectral fit using the timing-motivated parameters and report the detection of a broad Fe K emission line, requiring an additional model component beyond the reflection spectrum. We discuss links between this source and other narrow-line Seyfert 1 sources that show evidence of jet activity, finding similarities among this currently very limited sample of interesting objects. [ABSTRACT FROM AUTHOR]

We explore a disc origin for the highly blueshifted, variable absorption lines seen in the X-ray spectrum of the narrow-line Seyfert 1 galaxy IRAS 13224−3809. The blueshift corresponds to a velocity of ∼0.25 c. Such features in other active galactic nuclei are often interpreted as ultrafast outflows. The velocity is of course present in the orbital motions of the inner disc. The absorption lines in IRAS 13224−3809 are best seen when the flux is low and the reflection component of the disc is strong relative to the power-law continuum. The spectra are consistent with a model in which the reflection component passes through a thin, highly ionized absorbing layer at the surface of the inner disc, the blueshifted side of which dominates the flux due to relativistic aberration (the disc inclination is about 70°). No fast outflow need occurs beyond the disc. [ABSTRACT FROM AUTHOR]

We present XMM–Newton, NuSTAR, Swift , and Hubble Space Telescope observations of the Narrow-line Seyfert 1 galaxy Mrk 335 in a protracted low state in 2018 and 2019. The X-ray flux is at the lowest level so far observed, and the extremely low continuum flux reveals a host of soft X-ray emission lines from photoionized gas. The simultaneous UV flux drop suggests that the variability is intrinsic to the source, and we confirm this with broad-band X-ray spectroscopy. The dominance of the soft X-ray lines at low energies and distant reflection at high energies, is therefore due to the respective emission regions being located far enough from the X-ray source that they have not yet seen the flux drop. Between the two XMM–Newton spectra, taken 6 months apart, the emission line ratio in the O  vii triplet changes drastically. We attribute this change to a drop in the ionization of intervening warm absorption, which means that the absorber must cover a large fraction of the line emitting region, and extend much further from the black hole than previously assumed. The HST spectrum, taken in 2018, shows that new absorption features have appeared on the blue wings of C  iii *, Ly α, N  v , Si  iv , and C  iv , likely due to absorbing gas cooling in response to the low flux state. [ABSTRACT FROM AUTHOR]

A multi-epoch X-ray spectral and variability analysis is conducted for the narrow-line Seyfert 1 (NLS1) active galactic nucleus (AGN) Mrk 478. All available X-ray data from XMM–Newton and Suzaku satellites, spanning from 2001 to 2017, are modelled with a variety of physical models, including partial covering, soft Comptonization, and blurred reflection, to explain the observed spectral shape and variability over the 16 yr. All models are a similar statistical fit to the data sets, though the analysis of the variability between data sets favours the blurred reflection model. In particular, the variability can be attributed to changes in flux of the primary coronal emission. Different reflection models fit the data equally well, but differ in interpretation. The use of reflionx predicts a low disc ionization and power law dominated spectrum, while relxill predicts a highly ionized and blurred reflection dominated spectrum. A power law dominated spectrum might be more consistent with the normal X-ray-to-UV spectral shape (αox). Both blurred reflection models suggest a rapidly spinning black hole seen at a low inclination angle, and both require a sub-solar (∼0.5) abundance of iron. All physical models require a narrow emission feature at |$6.7{\rm \, keV}$| likely attributable to Fe  xxv emission, while no evidence for a narrow |$6.4{\rm \, keV}$| line from neutral iron is detected. [ABSTRACT FROM AUTHOR]

We have carried out a systematic analysis of the nearby (z = 0.0279) active galaxy Zw 229.015 using multi-epoch, multi-instrument, and deep pointed observations with XMM–Newton, Suzaku, Swift ,and NuSTAR. Spectral and temporal variability are examined in detail on both the long (weeks-to-years) and short (hours) time-scales. A deep Suzaku  observation of the source shows two distinct spectral states; a bright-soft state and a dim-hard state in which changes in the power-law component account for the differences. Partial covering, blurred reflection, and soft Comptonization models describe the X-ray spectra comparably well, but the smooth, rather featureless, spectrum may be favouring the soft Comptonization scenario. Moreover, independent of the spectral model, the observed spectral variability is ascribed to the changes in the power-law continuum only and do not require changes in the properties of the absorber or blurred reflector incorporated in the other scenarios. The multi-epoch observations between 2009 and 2018 can be described in similar fashion. This could be understood if the primary emission is originating at a large distance from a standard accretion disc or if the disc is optically thin and geometrically thick as recently proposed for Zw 229.015. Our investigation shows that Zw 229.015 behaves similar to sources like Akn 120 and Mrk 530 that exhibit a strong soft excess, but weak Compton hump and Fe Kα emission. [ABSTRACT FROM AUTHOR]

A number of works point to the presence of narrow emission features at unusual energies in the X-ray spectra of active galactic nuclei or to potentially low iron abundances as possible evidence for the spallation of iron. With the imminence of high-resolution calorimeter spectroscopy, the potential to test spallation models in astrophysical sources will soon be possible. Previously determined nuclear spallation reactions of Fe are recalculated making use of improved total inelastic and partial reaction cross-sections that result in different absolute and relative abundances of the main spallation elements Mn, Cr, V, and Ti. The effects of ionization and dynamics near the black hole are examined in simulated spectra with CCD and calorimeter (i.e. Hitomi) resolution. With high resolution, differences in relative abundances and ionization should be detectable if spallation is originating at large distances from the black hole (e.g. torus or disc wind), where blurring is not significant. If spallation were occurring in the inner accretion disc, it would likely be undetected as blurring effects would cause significant blending of spectral features. [ABSTRACT FROM AUTHOR]

A triggered |$140{\rm \, ks}$| XMM–Newton observation of the narrow-line Seyfert 1 (NLS1) Mrk 335 in 2015 December caught the active galaxy at its lowest X-ray flux since 2007. The NLS1 is relatively quiescent for the first |${\sim }120{\rm \, ks}$| of the observation before it flares in brightness by a factor of about five in the last |$20{\rm \, ks}$|⁠. Although only part of the flare is captured before the observation is terminated, the data reveal significant differences between the flare and quiescent phases. During the low-flux state, Mrk 335 demonstrates a reflection-dominated spectrum that results from a compact corona around a Kerr black hole. In addition to the rapid brightening, the flare is further described by spectral softening and a falling reflection fraction that are consistent with previous observations advocating at least part of the corona in Mrk 335 could be the base of an aborted jet. The spectrum during the flaring interval reveals several residuals between the 2σ and 3σ level that could be attributed to absorption lines from a highly ionized plasma that is moving outwards at |$v$| ∼ 0.12 c. It could be that the increased luminosity during the flare enhances the radiation pressure sufficiently to launch a possible wind. If the wind is indeed responding to the change in corona luminosity then it must be located within |${\sim }80{\, r_{\rm g}}$|⁠. The escape velocity at this distance is comparable to the estimated wind velocity. If confirmed, this is the first example of a radio-quiet active galactic nucleus exhibiting behaviour consistent with both diffuse and collimated outflow. [ABSTRACT FROM AUTHOR]

We present results from a deep, coordinated XMM–Newton  +  NuSTAR observation of the Seyfert 2 galaxy IRAS 00521−7054. The NuSTAR data provide the first detection of this source in high-energy X-rays (E > 10 keV), and the broad-band data show this to be a highly complex source which exhibits relativistic reflection from the inner accretion disc, further reprocessing by more distant material, neutral absorption, and evidence for ionized absorption in an extreme, ultrafast outflow (⁠|$v$| out ∼ 0.4 c). Based on lamppost disc reflection models, we find evidence that the central supermassive black hole is rapidly rotating (a > 0.77), consistent with previous estimates from the profile of the relativistic iron line, and that the accretion disc is viewed at a fairly high inclination (i ∼ 59°). Based on extensive simulations, we find the ultrafast outflow is detected at ∼4σ significance (or greater). We also estimate that the extreme outflow should be sufficient to power galaxy-scale feedback, and may even dominate the energetics of the total output from the system. [ABSTRACT FROM AUTHOR]

Principal component analysis (PCA) is applied to a variety of blazars to examine X-ray spectral variability. Data from nine different objects are analysed in two ways: long-term, which examines variability trends across years or decades, and short-term, which looks at variability within a single observation. The results are then compared to simulated spectra in order to identify the physical components that they correspond to. It is found that long-term variability for all objects is dominated by changes in a single power-law component. The primary component is responsible for more than 84 per cent of the variability in every object, while the second component is responsible for at least 3 per cent. Small differences in the shapes of these components can be used to predict qualities such as the degree to which spectral parameters are varying relative to one another, and correlations between spectral hardness and flux. Short-term variability is less clear-cut, with no obvious physical analogue for some of the PCA results. We discuss the simulation process, and specifically remark on the consequences of the breakdown of the linearity assumption of PCA and how it manifests in the real data. We conclude that PCA is a useful tool for analysing variability, but only if its underlying assumptions and limitations are understood. [ABSTRACT FROM AUTHOR]

We present new XMM–Newton observations of the intriguing warm absorber in I Zwicky 1. This luminous and nearby narrow-line Seyfert 1 galaxy shows ionized absorption by two components of outflowing gas; a low and a high-ionization phase with log ξ ∼ 0 and log ξ ∼ 2, respectively. Detailed modelling of these data reveal a complex and variable multiphase warm absorber. However, we find the changes in the ionization state of the gas not to be straightforwardly correlated with the variability of the intrinsic continuum source, in apparent contrast with photoionization equilibrium. The observed variability hints instead at a close connection between the two gas components, possibly both directly connected to the accretion disc activity. We thus suggest a phenomenological model capable of explaining these observations, consisting of a clumpy outflow where the high and the low-ionization components are closely linked. Changes in ionization over the years are mainly driven by the different densities of the clumps crossing the observer's line-of-sight, in which the 'skin' layer facing the source accounts for the more ionized component. [ABSTRACT FROM AUTHOR]

We collate active galactic nuclei (AGN) with reported detections of both relativistic reflection and ultrafast outflows. By comparing the inclination of the inner disc from reflection with the line-of-sight velocity of the outflow, we show that it is possible to meaningfully constrain the geometry of the absorbing material. We find a clear relation between the velocity and inclination, and demonstrate that it can potentially be explained either by simple wind geometries or by absorption from the disc surface. Due to systematic errors and a shortage of high-quality simultaneous measurements our conclusions are tentative, but this study represents a proof-of-concept that has a great potential. [ABSTRACT FROM AUTHOR]

A 2012 Suzaku observation of the Seyfert 1.5 galaxy Markarian 530 was analysed and found to exhibit two distinct modes of variability, which were found to be independent from one another. First, the spectrum undergoes a smooth transition from a soft to hard spectrum. Secondly, the spectrum displays more rapid variability seemingly confined to a very narrow energy band (∼1−3 keV). Three physical models (blurred reflection, partial covering, and soft Comptonization) were explored to characterize the average spectrum of the observation as well as the spectral state change. All three models were found to fit the average spectrum and the spectral changes equally well. The more rapid variability appears as two cycles of a sinusoidal function, but we cannot attribute this to periodic variability. The Fe Kα band exhibits a narrow 6.4 keV emission line consistent with an origin from the distant torus. In addition, features blueward of the neutral iron line are consistent with emission from He-like and H-like iron that could be originating from the highly ionized layer of the torus, but a broad Gaussian profile at ∼6.7 keV also fits the spectrum well. [ABSTRACT FROM AUTHOR]

We examine a 200 ks XMM–Newton observation of the narrow-line Seyfert 1 galaxy Mrk 493. The active galaxy was half as bright as in a previous 2003 snapshot observation and the current lower flux enables a study of the putative reflection component in detail. We determine the characteristics of the 2015 X-ray continuum by first analysing the short-term variability using model-independent techniques. We then continue with a time-resolved analysis including spectral fitting and modelling the fractional variability. We determine that the variability arises from changes in the amount of primary flux striking the accretion disc, which induces changes in the ionization parameter and flux of the blurred reflection component. The observations seem consistent with the picture that the primary source is of roughly constant brightness and that variations arise from changes in the degree of light bending happening in the vicinity of the supermassive black hole. [ABSTRACT FROM AUTHOR]

We present a detailed spectral analysis of the recent 1.5 Ms XMM–Newton observing campaign on the narrow-line Seyfert 1 galaxy IRAS 13224−3809, taken simultaneously with 500 ks of NuSTAR data. The X-ray light curve shows three flux peaks, registering at about 100 times the minimum flux seen during the campaign, and rapid variability with a time-scale of kiloseconds. The spectra are well fit with a primary power-law continuum, two relativistic-blurred reflection components from the inner accretion disc with very high iron abundance, and a simple blackbody-shaped model for the remaining soft excess. The spectral variability is dominated by the power-law continuum from a corona region within a few gravitational radii from the black hole. Additionally, blueshifted Ne x, Mg xii, Si xiv, and S xvi absorption lines are identified in the stacked low-flux spectrum, confirming the presence of a highly ionized outflow with velocity up to v = 0.267 and 0.225 c. We fit the absorption features with xstar models and find a relatively constant velocity outflow through the whole observation. Finally, we replace the bbody and supersolar abundance reflection models by fitting the soft excess successfully with the extended reflection model relxillD, which allows for higher densities than the standard relxill model. This returns a disc electron density ne > 1018.7 cm−3 and lowers the iron abundance from $Z_{\rm Fe} = 24^{+3}_{-4}\, \mathrm{Z}_{\odot }$ with ne ≡ 1015 cm−3 to $Z_{\rm Fe} = 6.6^{+0.8}_{-2.1}\, \mathrm{Z}_{\odot }$. [ABSTRACT FROM AUTHOR]

Ultrafast outflows (UFOs) are the most extremewinds launched by active galactic nuclei (AGN) due to their mildly relativistic speeds (~0.1-0.3c) and are thought to significantly contribute to galactic evolution via AGN feedback. Their nature and launching mechanism are however not well understood. Recently, we have discovered the presence of a variable UFO in the narrowline Seyfert 1 IRAS 13224-3809. TheUFOvaries in response to the brightness of the source. In this work we perform flux-resolved X-ray spectroscopy to study the variability of the UFO and found that the ionization parameter is correlated with the luminosity. In the brightest states the gas is almost completely ionized by the powerful radiation field and the UFO is hardly detected. This agrees with our recent results obtained with principal component analysis. We might have found the tip of the iceberg: the high ionization of the outflowing gas may explain why it is commonly difficult to detect UFOs in AGN and possibly suggest that we may underestimate their actual feedback. We have also found a tentative correlation between the outflow velocity and the luminosity, which is expected from theoretical predictions of radiation-pressure-driven winds. This trend is rather marginal due to the Fe XXV-XXVI degeneracy. Further work is needed to break such degeneracy through time-resolved spectroscopy. [ABSTRACT FROM AUTHOR]

We present results from the optical, ultraviolet, and X-ray monitoring of the NLS1 galaxy IRAS 13224-3809 taken with Swift and XMM-Newton during 2016. IRAS 13224-3809 is the most variable bright AGN in the X-ray sky and shows strong X-ray reflection, implying that the X-rays strongly illuminate the inner disc. Therefore, it is a good candidate to study the relationship between coronal X-ray and disc UV emission. However, we find no correlation between the X-ray and UV flux over the available ∼40 d monitoring, despite the presence of strong X-ray variability and the variable part of the UV spectrum being consistent with irradiation of a standard thin disc. This means either that the X-ray flux which irradiates the UV emitting outer disc does not correlate with the X-ray flux in our line of sight and/or that another process drives the majority of the UV variability. The former case may be due to changes in coronal geometry, absorption or scattering between the corona and the disc. [ABSTRACT FROM AUTHOR]

We report on X-ray observations of the radio-intermediate, X-ray bright Seyfert 1 galaxy, III Zw2, obtained withXMM-Newton, Suzaku, and Swift over the past 17 yr. The source brightness varies significantly over yearly time-scales, but more modestly over periods of days. Pointed observations with XMM-Newton in 2000 and Suzaku in 2011 show spectral differences despite comparable X-ray fluxes. The Suzaku spectra are consistent with a power-law continuum and a narrow Gaussian emission feature at ∼6.4 keV, whereas the earlier XMM-Newton spectrum requires a broader Gaussian profile and soft-excess below ∼2 keV. A potential interpretation is that the primary power-law emission, perhaps from a jet base, preferentially illuminates the inner accretion disc in 2000, but the distant torus in 2011. The interpretation could be consistent with the hypothesized precessing radio jet in III Zw 2 that may have originated from disc instabilities due to an ongoing merging event. [ABSTRACT FROM AUTHOR]

To gain a better understanding of the inner disc region that comprises active galactic nuclei, it is necessary to understand the pattern in which the disc is illuminated (the emissivity profile) by X-rays emitted from the continuum source above the black hole (corona). The differences in the emissivity profiles produced by various corona geometries are explored via general relativistic ray tracing simulations. Through the analysis of various parameters of the geometries simulated it is found that emissivity profiles produced by point source and extended geometries such as cylindrical slabs and spheroidal coronae placed on the accretion disc are distinguishable. Profiles produced by point source and conical geometries are not significantly different, requiring an analysis of reflection fraction to differentiate the two geometries. Beamed point and beamed conical sources are also simulated in an effort to model jet-like coronae, though the differences here are most evident in the reflection fraction. For a point source we determine an approximation for the measured reflection fraction with the source height and velocity. Simulating spectra from the emissivity profiles produced by the various geometries produce distinguishable differences. Overall spectral differences between the geometries do not exceed 15 per cent in the most extreme cases. It is found that emissivity profiles can be useful in distinguishing point source and extended geometries given highquality spectral data of extreme, bright sources over long exposure times. In combination with reflection fraction, timing and spectral analysis we may use emissivity profiles to discern the geometry of the X-ray source. [ABSTRACT FROM AUTHOR]

X-ray spectral timing analysis is presented of XMM-Newton observations of the narrow-line Seyfert 1 galaxy I Zwicky 1 taken in 2015 January. After exploring the effect of background flaring on timing analyses, X-ray time lags between the reflection-dominated 0.3-1.0 keV energy and continuum-dominated 1.0-4.0 keV band are measured, indicative of reverberation off the inner accretion disc. The reverberation lag time is seen to vary as a step function in frequency; across lower frequency components of the variability, 3 × 10-4-1.2 × 10-3 Hz a lag of 160 s is measured, but the lag shortens to (59±4) s above 1.2×10-3 Hz. The lag-energy spectrum reveals differing profiles between these ranges with a change in the dip showing the earliest arriving photons. The low-frequency signal indicates reverberation of X-rays emitted from a corona extended at low height over the disc, while at high frequencies, variability is generated in a collimated core of the corona through which luminosity fluctuations propagate upwards. Principal component analysis of the variability supports this interpretation, showing uncorrelated variation in the spectral slope of two power-law continuum components. The distinct evolution of the two components of the corona is seen as a flare passes inwards from the extended to the collimated portion. An increase in variability in the extended corona was found preceding the initial increase in X-ray flux. Variability from the extended corona was seen to die away as the flare passed into the collimated core leading to a second sharper increase in the X-ray count rate. [ABSTRACT FROM AUTHOR]

Being one of only two fundamental properties black holes possess, the spin of supermassive black holes (SMBHs) is of great interest for understanding accretion processes and galaxy evolution. However, in these early days of spin measurements, consistency and reproducibility of spin constraints have been a challenge. Here, we focus on X-ray spectral modelling of active galactic nuclei (AGN), examining how well we can truly return known reflection parameters such as spin under standard conditions.We have created and fit over 4000 simulated Seyfert 1 spectra each with 375±1k counts. We assess the fits with reflection fraction of R = 1 as well as reflection-dominated AGN with R = 5.We also examine the consequence of permitting fits to search for retrograde spin. In general, we discover that most parameters are overestimated when spectroscopy is restricted to the 2.5-10.0 keV regime and that models are insensitive to inner emissivity index and ionization. When the bandpass is extended out to 70 keV, parameters are more accurately estimated. Repeating the process for R = 5 reduces our ability to measure photon index (~3 to 8 per cent error and overestimated), but increases precision in all other parameters - most notably ionization, which becomes better constrained (±45 erg cm s-1) for low-ionization parameters (ξ < 200 erg cm s-1). In all cases, we find the spin parameter is only well measured for the most rapidly rotating SMBHs (i.e. a > 0.8 to about ±0.10) and that inner emissivity index is never well constrained. Allowing our model to search for retrograde spin did not improve the results. [ABSTRACT FROM AUTHOR]

The cosmic X-ray background (CXB) is the total emission from past accretion activity on to supermassive black holes in active galactic nuclei (AGN) and peaks in the hard X-ray band (30 keV). In this paper, we identify a significant selection effect operating on the CXB and flux-limited AGN surveys, and outline how they must depend heavily on the spin distribution of black holes. We show that, due to the higher radiative efficiency of rapidly spinning black holes, they will be over-represented in the X-ray background, and therefore could be a dominant contributor to the CXB. Using a simple bimodal spin distribution, we demonstrate that only 15 per cent maximally spinning AGN can produce 50 per cent of the CXB. We also illustrate that invoking a small population of maximally spinning black holes in CXB synthesis models can reproduce the CXB peak without requiring large numbers of Comptonthick AGN. The spin bias is even more pronounced for flux-limited surveys: 7 per cent of sources with maximally spinning black holes can produce half of the source counts. The detectability for maximum spin black holes can be further boosted in hard (>10 keV) Xrays by up to ~60 per cent due to pronounced ionized reflection, reducing the percentage of maximally spinning black holes required to produce half of the CXB or survey number counts further. A host of observations are consistent with an over-representation of high-spin black holes. Future NuSTAR and ASTRO-H hard X-ray surveys will provide the best constraints on the role of spin within the AGN population. [ABSTRACT FROM AUTHOR]

Monitoring of the narrow line Seyfert 1 galaxy Markarian 335 (Mrk 335) with the Swift satellite discovered an X-ray flare beginning 2014 August 29. At the peak, the 0.5-5 keV count rate had increased from that in the low-flux state by a factor of 10. A target of opportunity observation was triggered with NuSTAR, catching the decline of the flare on 2014 September 20. We present a joint analysis of Swift and NuSTAR observations to understand the cause of this flare. The X-ray spectrum shows an increase in directly observed continuum flux and the softening of the continuum spectrum to a photon index of 2.49-0.07+0.08 compared to the previous low-flux observations. The X-ray spectrum remains well described by the relativistically blurred reflection of the continuum from the accretion disc whose emissivity profile suggests that it is illuminated by a compact X-ray source, extending at most 5.2 rg over the disc. A very low reflection fraction of 0.41-0.15+0.15 is measured, unexpected for such a compact corona. The X-ray flare is, hence, interpreted as arising from the vertical collimation and ejection of the X-ray emitting corona at a mildly relativistic velocity, causing the continuum emission to be beamed away from the disc. As the flare subsides, the base of this jet-like structure collapses into a compact X-ray source that provides the majority of the radiation that illuminates the disc while continuum emission is still detected from energetic particles further out, maintaining the low reflection fraction. [ABSTRACT FROM AUTHOR]

We examine simultaneous X-ray and UV light curves from multi-epoch 8 d XMM-Newton observations of the narrow line Seyfert 1 galaxy 1H 0707-495. The simultaneous observations reveal that both X-ray and UV emission are variable and that the amplitude of the X-ray variations is significantly greater than that of the UV variations in both epochs. Using a discrete correlation function the X-ray and UV light curves were examined for correlation on time-scales up to 7 d. Low-significance (~95 per cent confidence) correlations with the UV leading the X-ray variations are observed. The lack of a significant correlation between the UV and X-ray bands seems consistent with the X-ray source being centrally compact and dominated by light bending close to the black hole. In addition, multiband X-ray light curves were examined for correlations on similar time-scales. Highly significant (>99.9 per cent confidence) correlations were observed at zero lag consistent with previous studies of this active galactic nucleus. [ABSTRACT FROM AUTHOR]

A multi-epoch, multi-instrument analysis of the Seyfert 1 galaxy HE 0436-4717 is conducted using optical to X-ray data from XMM-Newton and Swift (including the Burst Alert Telescope). Fitting of the UV-to-X-ray spectral energy distribution shows little evidence of extinction and the X-ray spectral analysis does not confirm previous reports of deep absorption edges from OVIII.HE 0436-4717 is a 'bare' Seyfertwith negligible line-of-sight absorptionmaking it ideal to study the central X-ray emitting region. Three scenarios were considered to describe the X-ray data: partial covering absorption, blurred reflection, and soft Comptonization. All three interpretations describe the 0.5-10.0 keV spectra well. Extrapolating the models to 100 keV results in poorer fits for the partial covering model.When also considering the rapid variability during one of the XMM-Newton observations, the blurred reflection model appears to describe all the observations in the most self-consistent manner. If adopted, the blurred reflection model requires a very low iron abundance in HE 0436-4717. We consider the possibilities that this is an artefact of the fitting process, but it appears possible that it is intrinsic to the object. [ABSTRACT FROM AUTHOR]

Variations in the X-ray emission from the narrow-line Seyfert 1 galaxy, Markarian 335, are studied on both long and short time-scales through observations made between 2006 and 2013 with XMM-Newton, Suzaku and NuSTAR. Changes in the geometry and energetics of the corona that give rise to this variability are inferred through measurements of the relativistically blurred reflection seen from the accretion disc. On long time-scales, we find that during the high-flux epochs the corona has expanded, covering the inner regions of the accretion disc out to a radius of 26-7+10 rg. The corona contracts to within 12rg and 5rg in the intermediate and low-flux epochs, respectively. While the earlier high-flux observation made in 2006 is consistent with a corona extending over the inner part of the accretion disc, a later high-flux observation that year revealed that the X-ray source had become collimated into a vertically extended jet-like corona and suggested relativistic motion of material upwards. On short time-scales, we find that an X-ray flare during a low-flux epoch in 2013 corresponded to a reconfiguration from a slightly extended corona to one much more compact, within just 2 ~ 3rg of the black hole. There is evidence that during the flare itself, the spectrum softened and the corona became collimated and slightly extended vertically as if a jet-launching event was aborted. Understanding the evolution of the X-ray emitting corona may reveal the underlying mechanism by which the luminous X-ray sources in AGN are powered. [ABSTRACT FROM AUTHOR]

We consider the Comptonization of the photons that make up the relativistically blurred reflection that is commonly detected from the accretion discs of active galactic nuclei by the coronae of energetic particles believed to give rise to the powerful X-ray continua by the inverse-Compton scattering of thermal seed photons from the disc. Recent measurements of the emissivity profiles of accretion discs as well as reverberation time lags between the primary X-ray continuum and the reflection suggest that this corona is situated at a low height above the disc and extends radially, tens of gravitational radii over the disc surface, hence should also Compton scatter the reflected X-rays. We find that the detection of blurred reflection from as close in as the innermost stable circular orbits (ISCOs) of maximally rotating black holes is consistent with such coronae, but requires that the corona be patchy, consisting perhaps of a number of isolated flares throughout the region. Considering only the requirement that it be possible to detect reflection from the ISCO, we find that at any given moment, the covering fraction of the inner part of the accretion disc by the corona needs to be less than 85 per cent, although the detection of ‘reflection-dominated’ spectra in which the total reflected flux exceeds that seen in the continuum requires covering fractions as low as 50 or 25 per cent. [ABSTRACT FROM AUTHOR]

We report on the deepest X-ray observation of the narrow-line Seyfert 1 galaxy Mrk 335 in the low-flux state obtained with Suzaku. The data are compared to a 2006 high-flux Suzaku observation when the source was ∼10 times brighter. Describing the two flux levels self-consistently with partial covering models would require extreme circumstances, as the source would be subject to negligible absorption during the bright state and 95 per cent covering with near Compton-thick material when dim. Blurred reflection from an accretion disc around a nearly maximum spinning black hole (a > 0.91, with preference for a spin parameter as high as ∼0.995) appears more likely and is consistent with the long-term and rapid variability. Measurements of the emissivity profile and spectral modelling indicate the high-flux Suzaku observation of Mrk 335 is consistent with continuum-dominated, jet-like emission (i.e. beamed away from the disc). It can be argued that the ejecta must be confined to within ∼ 25rg if it does not escape the system. During the low-flux state, the corona becomes compact and only extends to about 5rg from the black hole, and the spectrum becomes reflection dominated. The low-frequency lags measured at both epochs are comparable indicating that the accretion mechanism is not changing between the two flux levels. Various techniques to study the spectral variability (e.g. principal component analysis, fractional variability, difference spectra, and hardness ratio analysis) indicate that the low-state variability is dominated by changes in the power-law flux and photon index, but that changes in the ionization state of the reflector are also required. Most notably, the ionization parameter becomes inversely correlated with the reflected flux after a long-duration flare-like event during the observation. [ABSTRACT FROM AUTHOR]

The extreme narrow-line Seyfert 1 galaxy IRAS 13224−3809 shows significant variability, frequency-dependent time lags, and strong Fe K line and Fe L features in the long 2011 XMM–Newton observation. In this work, we study the spectral properties of IRAS 13224−3809 in detail, and carry out a series of analyses to probe the nature of the source, focusing in particular on the spectral variability exhibited. The reflection grating spectrometer spectrum shows no obvious signatures of absorption by partially ionized material (‘warm’ absorbers). We fit the 0.3–10.0 keV spectra with a model that includes relativistic reflection from the inner accretion disc, a standard power-law active galactic nucleus continuum, and a low-temperature (∼0.1 keV) blackbody, which may originate in the accretion disc, either as direct or reprocessed thermal emission. We find that the reflection model explains the time-averaged spectrum well, and we also undertake flux-resolved and time-resolved spectral analyses, which provide evidence of gravitational light-bending effects. Additionally, the temperature and flux of the blackbody component are found to follow the L ∝ T4 relation expected for simple thermal blackbody emission from a constant emitting area, indicating a physical origin for this component. [ABSTRACT FROM AUTHOR]

The X-ray spectra of the narrow-line Seyfert 1 galaxy, 1H 0707−495, obtained with XMM–Newton, from time periods of varying X-ray luminosity are analysed in the context of understanding the changes to the X-ray emitting corona that lead to the extreme variability seen in the X-ray emission from active galactic nuclei (AGN). The emissivity profile of the accretion disc, illuminated by the X-ray emitting corona, along with previous measurements of reverberation time lags, is used to infer the spatial extent of the X-ray source. By fitting a twice-broken power-law emissivity profile to the relativistically broadened iron Kα fluorescence line, it is inferred that the X-ray emitting corona expands radially, over the plane of the accretion disc, by 25 to 30 per cent as the luminosity increases, contracting again as the luminosity decreases, while increases in the measured reverberation lag as the luminosity increases would require also variation in the vertical extent of the source above the disc. The spectrum of the X-ray continuum is found to soften as the total X-ray luminosity increases and we explore the variation in reflected flux as a function of directly observed continuum flux. These three observations combined with simple, first-principles models constructed from ray-tracing simulations of extended coronæ self-consistently portray an expanding corona whose average energy density decreases, but with a greater number of scattering particles as the luminosity of this extreme object increases. [ABSTRACT FROM PUBLISHER]

We present 3–50 keV NuSTAR observations of the active galactic nuclei Mrk 335 in a very low flux state. The spectrum is dominated by very strong features at the energies of the iron line at 5–7 keV and Compton hump from 10–30 keV. The source is variable during the observation, with the variability concentrated at low energies, which suggesting either a relativistic reflection or a variable absorption scenario. In this work, we focus on the reflection interpretation, making use of new relativistic reflection models that self consistently calculate the reflection fraction, relativistic blurring and angle-dependent reflection spectrum for different coronal heights to model the spectra. We find that the spectra can be well fitted with relativistic reflection, and that the lowest flux state spectrum is described by reflection alone, suggesting the effects of extreme light-bending occurring within ∼2 gravitational radii (RG) of the event horizon. The reflection fraction decreases sharply with increasing flux, consistent with a point source moving up to above 10 RG as the source brightens. We constrain the spin parameter to greater than 0.9 at the 3σ confidence level. By adding a spin-dependent upper limit on the reflection fraction to our models, we demonstrate that this can be a powerful way of constraining the spin parameter, particularly in reflection dominated states. We also calculate a detailed emissivity profile for the iron line, and find that it closely matches theoretical predictions for a compact source within a few RG of the black hole. [ABSTRACT FROM PUBLISHER]

The narrow-line Seyfert 1 galaxy IRAS 13224−3809 has been observed with XMM–Newton for 500 ks. The source is rapidly variable on time-scales down to a few 100 s. The spectrum shows strong broad Fe − Kand L emission features which are interpreted as arising from reflection from the inner parts of an accretion disc around a rapidly spinning black hole. Assuming a power law emissivity for the reflected flux and that the innermost radius corresponds to the innermost stable circular orbit, the black hole spin is measured to be 0.989 with a statistical precision better than 1 per cent. Systematic uncertainties are discussed. A soft X-ray lag of 100 s confirms this scenario. The bulk of the power-law continuum source is located at a radius of 2–3 gravitational radii. [ABSTRACT FROM AUTHOR]

We present an X-ray spectral analysis of a large sample of 25 ‘bare’ active galactic nuclei (AGN), sources with little or no complicating intrinsic absorption, observed with Suzaku. Our work focuses on studying the potential contribution from relativistic disc reflection and examining the implications of this interpretation for the intrinsic spectral complexities frequently displayed by AGN in the X-ray bandpass. During the analysis, we take the unique approach of attempting to simultaneously undertake a systematic analysis of the whole sample, as well as a detailed treatment of each individual source, and find that disc reflection has the required flexibility to successfully reproduce the broad-band spectrum observed for all of the sources considered. Where possible, we use the reflected emission to place constraints on the black hole spin for this sample of sources. Our analysis suggests a general preference for rapidly rotating black holes, which if taken at face value is most consistent with the scenario in which supermassive black hole growth is dominated by prolonged, ordered accretion. However, there may be observational biases towards AGN with high spin in the compiled sample, limiting our ability to draw strong conclusions for the general population at this stage. Finally, contrary to popular belief, our analysis also implies that the dichotomy between radio-loud/radio-quiet AGN is not solely related to black hole spin. [ABSTRACT FROM AUTHOR]

As part of a long-term monitoring campaign of Mrk 335, deep XMM–Newton observations catch the narrow-line Seyfert 1 galaxy (NLS1) in a complex, intermediate flux interval as the active galaxy is transiting from low to high flux. Other works on these same data examined the general behaviour of the NLS1 and the conditions of its warm absorber. The analysis presented here demonstrates the X-ray continuum and timing properties can be described in a self-consistent manner adopting a blurred reflection model without any need to invoke partial covering. The rapid spectral variability appears to be driven by changes in the shape of the primary emitter that is illuminating the inner accretion disc around a rapidly spinning black hole (a > 0.7). While light bending is certainly prominent, the rather constant emissivity profile and break radius obtained in our spectral fitting suggest that the blurring parameters do not change as would be expected if the primary source varies its distance from the disc. Instead changes could be intrinsic to the power-law component. One possibility is that material in an unresolved jet above the disc falls to combine with material at the base of the jet producing the changes in the primary emitter (spectral slope and flux) without changing its distance from the disc. [ABSTRACT FROM PUBLISHER]

ABSTRACT PHL 1092 is a z ∼ 0.4 high-luminosity counterpart of the class of Narrow-Line Seyfert 1 galaxies. In 2008, PHL 1092 was found to be in a remarkably low X-ray flux state during an XMM-Newton observation. Its 2 keV flux density had dropped by a factor of ∼260 with respect to a previous observation performed 4.5 yr earlier. The ultraviolet (UV) flux remained almost constant, resulting in a significant steepening of the optical-to-X-ray slope αox from −1.57 to −2.51, making PHL 1092 one of the most extreme X-ray weak quasars with no observed broad absorption lines (BALs) in the UV. We have monitored the source since 2008 with three further XMM-Newton observations, producing a simultaneous UV and X-ray data base spanning almost 10 yr in total in the activity of the source. Our monitoring programme demonstrates that the αox variability in PHL 1092 is entirely driven by long-term X-ray flux changes. We apply a series of physically motivated models with the goal of explaining the UV-to-X-ray spectral energy distribution and the extreme X-ray and αox variability. We consider three possible models. (i) A breathing corona scenario in which the size of the X-ray-emitting corona is correlated with the X-ray flux. In this case, the lowest X-ray flux states of PHL 1092 are associated with an almost complete collapse of the X-ray corona down to the marginal stable orbit. (ii) An absorption scenario in which the X-ray flux variability is entirely due to intervening absorption. If so, PHL 1092 is a quasar with standard X-ray output for its optical luminosity, appearing as X-ray weak at times due to absorption. (iii) A disc-reflection-dominated scenario in which the X-ray-emitting corona is confined within a few gravitational radii from the black hole at all times. In this case, the intrinsic variability of PHL 1092 only needs to be a factor of ∼10 rather than the observed factor of ∼260. We discuss these scenarios in the context of non-BAL X-ray weak quasars. [ABSTRACT FROM AUTHOR]

The aims of this study were to investigate the role and relative importance of auscultation and echocardiography traits as risk factors for the diagnosis of subaortic (SubAS) and pulmonic (PS) stenosis and to estimate the heritability (h2) of cardiac measurements taken through echocardiography for a random sample of Italian Boxer dogs. The data were cardiovascular examination results of 1,283 Italian Boxer dogs (686 females and 597 males) enrolled in the national screening program for heart defects arranged by the Italian Boxer Club. Examinations were performed during a 6-yr period by a group of 7 veterinary cardiologists following a standard protocol. Occurrence and severity of SubAS and PS were diagnosed, taking into account clinical and echocardiography findings such as the grade of cardiac murmur, direct ultrasound imaging of the anatomic obstructive lesions, and values of aortic or pulmonary blood flow velocities. A Bayesian logistic regression analysis was performed to identify clinical and echocardiography variables related to SubAS and PS diagnosis. Estimation of variance components for clinical and echocardiography traits was performed using a mixed linear animal model, Bayesian procedures, and the Gibbs sampler. Prevalence of SubAS (PS) was 8.4% (2.2) and 10.7% (6.4) for female and male dogs, respectively. Cardiac murmur, peak velocities, and annulus areas behaved as risk factors for SubAS and PS. The risk of a positive diagnosis for SubAS was 3 times greater for dogs with aortic annulus area <2.1 cm2 relative to dogs with areas >2.37 cm2, 84 times greater for dogs showing aortic peak velocities >2.1.9 m/s relative to dogs with peak velocities <1.97 m/s, and 41 times greater for dogs with moderate to severe murmur grades relative to dogs with absent murmur. Similar results were obtained for PS. The estimated h2 for the occurrence of cardiac defects was 23.3% for SubAS and 8.6% for PS. Echocardiography and cardiac murmur grades exhibited moderate h2 estimates and exploitable additive genetic variation. The estimated h2 was 36, 24, and 20% for aortic annulus area, aortic peak velocity, and cardiac murmur score, respectively. For the area of the pulmonary annulus and peak pulmonary velocity, the estimated h2 were smaller, ranging from 9.5 to 12.8%. These measures are candidate indicator traits that might be effectively used in dog breeding to reduce the prevalence and severity of cardiac defects. [ABSTRACT FROM AUTHOR]

ABSTRACT The narrow-line Seyfert 1 Galaxy 1H 0707−495 went into a low state from 2010 December to 2011 February, discovered by a monitoring campaign using the X-Ray Telescope on the Swift satellite. We triggered a 100 ks XMM-Newton observation of the source in 2011 January, revealing the source to have dropped by a factor of 10 in the soft band, below 1 keV, and a factor of 2 at 5 keV, compared with a long observation in 2008. The sharp spectral drop in the source usually seen around 7 keV now extends to lower energies, below 6 keV in our frame. The 2011 spectrum is well fitted by a relativistically blurred reflection spectrum similar to that which fits the 2008 data, except that the emission is now concentrated solely to the central part of the accretion disc. The irradiating source must lie within 1 gravitational radius of the event horizon of the black hole, which spins rapidly. Alternative models are briefly considered, but none has any simple physical interpretation. [ABSTRACT FROM AUTHOR]