Pith. sign in

REVIEW 3 major objections 4 minor 1 cited by

Multi-epoch X-ray spectral analysis of the narrow-line Seyfert 1 galaxy Mrk 478

T0 review · 3 major / 4 minor · reviewed 2026-08-14 · deepseek-v4-flash

Challenge this review Re-run · record.json Download PDF Read on arXiv ↗ Review JSON

Pith's one-line read All XMM-Newton and Suzaku spectra of Mrk 478 from 2001 to 2017, modelled four ways, point to blurred reflection off the inner disc as the origin of its X-rays.

desk verdict A careful, transparent multi-epoch study that adds new data and a sensible PCA-model comparison, but the central preference for blurred reflection rests on a diagnostic the authors themselves concede is non-unique. read the letter →

arxiv 1909.01897 v1 pith:5ROCBTGP submitted 2019-09-04 astro-ph.HE

S. G. H. Waddell (1) , L. C. Gallo (1) , A. G. Gonzalez (1) , S. Tripathi (1) , A. Zoghbi (2) ((1) Saint Mary's Univ. , (2) Univ. of Michigan) This is my paper · ORCID
classification astro-ph.HE
keywords Mrk478narrow-lineSeyfert1galaxiesX-rayspectroscopyblurredreflectionblackholespinironabundanceprincipalcomponentanalysisactivegalacticnuclei
verification ladder T0 review T1 audit T2 compute T3 formal

The pith

A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.

The reading

This paper assembles every XMM-Newton and Suzaku observation of the narrow-line Seyfert 1 galaxy Mrk 478 from 2001 to 2017 and asks which physical picture best explains its soft X-ray excess and long-term variability. Partial covering, soft-Comptonisation, and blurred reflection all fit the time-averaged spectra about equally well. The deciding evidence is variability: hardness ratios stay nearly constant, and the first principal component of the combined spectra is flat, which the paper interprets as flux normalisation changes of a single spectral component. Only the blurred reflection models reproduce the flat principal component (reduced chi-squared of 4 and 6 versus 17 and 39 for the alternatives), so the paper concludes that blurred reflection is the most likely origin of the X-ray emission. Both reflection codes then imply a near-maximally spinning black hole seen at low inclination and an iron abundance around half the solar value.

What carries the argument

The discriminative tool is the principal component analysis (PCA) of the combined XMM-Newton epoch spectra. PC1 accounts for about 90 per cent of the variability and is nearly flat in energy, the signature seen when a single model component changes only in normalisation. The paper computes PCAs for 100 simulated data sets per model: partial covering and the soft-Comptonisation model produce strongly curved first components, while the blurred reflection models (relxill and reflionx, the latter convolved with the kerrconv relativistic blurring kernel) keep PC1 flat. This flatness, together with nearly constant hardness ratios, is the load-bearing bridge from statistically similar spectral fits to the preference for blurred reflection.

What would settle it

Take a long, high signal-to-noise NuSTAR observation of Mrk 478 covering $3$–$79$ keV. If the $15$–$100$ keV flux is detected at about $2\times10^{-12}$ erg cm$^{-2}$ s$^{-1}$, the level the soft-Comptonisation model predicts and that sits just at the Swift BAT threshold, the reflection preference would be falsified; the partial-covering and blurred-reflection models predict fluxes below that threshold. A second check: a narrow 6.4 keV neutral-iron line with equivalent width above about 90 eV would contradict the models' lack of a neutral distant reflector.

Watch

Extended reading notes

Core claim

The central claim is that the X-ray spectrum and variability of Mrk 478 are best explained by blurred reflection from the inner accretion disc, not by partial covering or a warm Comptonising corona. Over sixteen years the source changes by about a factor of two in 0.3–10 keV flux while its spectral shape stays nearly constant; this pattern is reproduced when the flux of a single dominant component varies, as in the reflection model. Within the reflection interpretation, the two codes disagree on whether the spectrum is reflection-dominated or power-law-dominated: relxill requires high ionisation ($\log\xi\approx3$) and $R\approx2$–$3.5$, while reflionx favours $\xi\approx50$ and $R\approx0.7$–$1.3$. They agree on the fundamental parameters, a spin of $a\approx0.94$–$0.98$, a low inclination below roughly $31^\circ$, and an iron abundance near $0.5$ times solar. Every model also requires a narrow $\approx6.7$ keV emission line attributable to Fe XXV, while no narrow 6.4 keV neutral-iron line is detected.

Load-bearing premise

The load-bearing premise is that a flat first principal component uniquely indicates that a single spectral component is changing only in normalisation; the paper itself notes that multiple variable absorption zones can also produce an overall flat PCA (Miller et al. 2008), so the data may not discriminate a single variable reflection component from more complex absorption variability.

Editorial extensions

If this is right

  • If blurred reflection is the right picture, the observed variability of Mrk 478 is largely normalisation changes in the coronal power law, with the disc response set by the illumination pattern.
  • The black hole in Mrk 478 is spinning near the maximum allowed value ($a\approx0.94$–$0.98$) and is viewed at low inclination ($i\lesssim31^\circ$), so the inner disc is seen close to face-on.
  • The iron abundance in the reflecting material is sub-solar, roughly 0.4–0.8 times the solar value depending on the code, making Mrk 478 one of the few AGN requiring under-abundant iron.
  • The lack of a narrow 6.4 keV line and the persistent 6.7 keV Fe XXV feature imply that there is no significant neutral reflecting torus along the line of sight, and that ionised iron emission arises further out, possibly in the torus inner layers or the broad-line region.
  • Hard X-ray observations, for example with NuSTAR, should distinguish the models, because the soft-Comptonisation model predicts a 15–100 keV flux near the Swift BAT survey threshold while the reflection models predict fluxes below it.

Reading between the lines

Editorial extensions of the paper, not claims the author makes directly.

  • A NuSTAR detection of Mrk 478 at the 15–100 keV flux predicted by the soft-Comptonisation model, just at the Swift BAT threshold, would not only falsify the reflection preference but would also make the warm-corona picture the leading explanation.
  • If the sub-solar iron abundance is real, it would make Mrk 478 a test case for chemical-enrichment histories in AGN discs: low star-formation efficiency, a deficit of Type Ia supernovae, or cosmic-ray spallation are the mechanisms the paper lists, and each makes a different prediction for other element abundances that future high-resolution spectra could check.
  • The flatness of PC1 could be probed with a dedicated monitoring campaign that splits the light curve into many short segments; if the flat shape persists while soft and hard bands remain correlated, the single-component reflection interpretation would be strengthened against multi-zone absorption alternatives like the one Miller et al. (2008) describe.
Share X Bluesky LinkedIn Reddit HN

Signed reviews

No signed human review yet.

Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, and a circularity audit.

Referee Report

3 major / 4 minor

Summary. The paper presents a multi-epoch X-ray spectral and variability analysis of the narrow-line Seyfert 1 galaxy Mrk 478, using all available XMM-Newton and Suzaku observations from 2001 to 2017. Four physical scenarios are fitted to the EPIC-pn and Suzaku FI spectra: a two-absorber partial-covering model, the OPTXAGNF soft-Comptonisation model, and blurred reflection models using RELXILL and REFLIONX. The spectra are statistically comparable across models, and the variability is characterized through light curves, hardness ratios, and principal component analysis (PCA). The authors argue that the flat shape of the first principal component, together with low hardness-ratio variability, favors the blurred reflection interpretation, and they report a rapidly spinning black hole, low inclination, and sub-solar iron abundance. A narrow 6.7 keV Fe XXV line is required by all models, while no narrow 6.4 keV line is detected.

Significance. If the central claim were fully established, the paper would provide a valuable addition to the debate on the origin of the soft excess in NLS1 galaxies and would support a blurred-reflection interpretation for Mrk 478 over its 16-year baseline. The analysis has notable strengths: it assembles the complete archival X-ray coverage of the source, uses MCMC to propagate parameter uncertainties, and carries out a PCA-based posterior predictive check of the competing models. The authors are also transparent about limitations, explicitly noting that multiple variable absorption zones can produce a flat PCA shape. However, the quantitative evidence for the central claim is currently incomplete: the favored reflection models produce PCA chi-squared values that are formally poor, and the flat-PCA diagnostic is conceded to be non-unique. The paper's conclusions are therefore conditional on additional model-comparison work.

major comments (3)
  1. [Section 4.5 and Section 5.2] The PCA comparison is the primary quantitative support for the central claim, but the reported statistics do not support the strength of the conclusion. The paper states that the simulated PCA for RELXILL and REFLIONX yield chi-squared per degree of freedom of 4 and 6, respectively, for 50 degrees of freedom. These values are formally unacceptable at any conventional significance level, and the statement in Section 4.5 that 'the overall shape is very close' is qualitative rather than statistical. To make the claim that the reflection model best reproduces the observed PCA, the authors need to calibrate the PCA chi-squared statistic, for example by computing posterior predictive p-values or the distribution of the statistic under simulated datasets from each model. Without such calibration, the conclusion in Section 5.2 that 'the reflection model is the most likely physical explanation' is not established.
  2. [Section 4.5 and Section 4.2] The flatness of the first principal component is not a unique diagnostic of a single variable component. The paper itself concedes in Section 4.5 that 'more complex physical scenarios, such as multiple variable absorption zones, can in some cases produce an overall flat PCA shape,' citing Miller et al. (2008). This concession is directly relevant to the partial-covering model, whose best fit in Section 4.2 already requires two absorbers and, as the authors note, requires non-spherically symmetric absorption to avoid detectable Fe K alpha lines. The authors state that the available data are insufficient to model more complex scenarios, but this means the preference for reflection over partial covering is an assumption rather than a tested result. The paper should either simulate a two-zone absorption model with varying column densities and covering fractions to show whether it can reproduce the observed PCA and hardness ratios, or soften the central claim accordingly.
  3. [Section 4 and Abstract] The abstract states that all models are a similar statistical fit, but the reported C-statistics and degrees of freedom are C/dof = 667/544 for partial covering, 609/546 for OPTXAGNF, 593/539 for RELXILL, and 606/539 for REFLIONX. The difference of roughly 74 in C-statistic between partial covering and RELXILL, even accounting for the non-Gaussian nature of the C-statistic, does not seem negligible, and the paper does not provide a calibrated model-comparison statistic such as AIC, BIC, or a posterior predictive check of the spectra themselves. Since the paper relies on the similarity of the spectral fits to motivate the variability-based comparison, this claim should be quantified or reworded.
minor comments (4)
  1. [Section 4.5] The text twice refers to 'first principle components'; the correct spelling is 'principal components'.
  2. [Section 4.5 and Figure 9] The upturn in PC1 above about 8.5 keV is attributed to background variations. It would strengthen the analysis to show that the PCA conclusions are unchanged if the band above 8.5 keV is excluded, given that several spectra are background-dominated at these energies.
  3. [Section 3] In the paragraph describing the long-term light curve, the phrase 'deviations from the mean are on the order of 80 per cent at the extremes' should specify whether this refers to count rate, flux, or fractional variability amplitude, to avoid ambiguity.
  4. [Section 4.2] In the discussion of the predicted Fe K alpha equivalent widths, the sentence beginning 'It is also, however, interesting to consider the ionisation on the other absorber' is awkwardly worded and should be revised for clarity.

Circularity Check

0 steps flagged · score 0.0 of 10

No significant circularity: the PCA-based model comparison and external consistency checks are independent of the model fitting; self-citations are not load-bearing.

full rationale

The paper's derivation chain is: (i) fit partial-covering, soft-Comptonisation, and blurred-reflection models to the multi-epoch X-ray spectra; (ii) compute a model-independent principal component analysis of the observed spectral variability; (iii) simulate PCA shapes from each best-fit model using the same allowed parameter variations; and (iv) compare the simulated PC1 shapes to the observed PC1. The observed PCA is not used as an input to any spectral fit, and the simulated PCA shapes are forward-modeled outputs of the fitted models, so no fitted quantity is being renamed as a prediction. The spin, inclination, and iron abundance are reported as best-fit parameters, not as predictions. The hardness-ratio flatness and alpha_ox values are independent diagnostics. The only self-citations, notably Zoghbi et al. (2008), are prior analyses of the same data used for context and comparison; the present paper recomputes its own hardness ratios and light curves, and the PCA model-selection argument does not rest on the previous paper's conclusions. Section 4.5 explicitly concedes that 'more complex physical scenarios, such as multiple variable absorption zones, can in some cases produce an overall flat PCA shape (see Miller et al. 2008), however, the available data are insufficient to model with more complex scenarios.' That is a stated limitation on discriminating power, not a circular reduction of the conclusion to its inputs. No equation or fitted parameter is defined in terms of the target claim, and no load-bearing uniqueness theorem is imported from the authors' prior work. Therefore the paper is self-contained against external benchmarks and shows no significant circularity.

Assumptions & free parameters 6 free parameters · 4 assumptions · 0 invented entities

The physical conclusions (spin, inclination, iron abundance) are fitted quantities inside two competing reflection codes. The model-selection argument assumes that the flat PCA shape is uniquely caused by single-component normalization variability, a point the paper itself qualifies. No new entities are introduced; no derivation is performed, so there are no standard-math axioms beyond the numerical tools used.

free parameters (6)
  • Black hole spin a = 0.94+/-0.02 (REFLIONX), 0.98+/-0.01 (RELXILL)
    Fitted to the blurred reflection line shapes; central to the claim of a rapidly spinning black hole.
  • Inclination i = <22 deg (REFLIONX), 31+/-8 deg (RELXILL)
    Fitted; used to claim a low viewing angle.
  • Iron abundance A_Fe = 0.44+/-0.28 (REFLIONX), 0.84+/-0.14 (RELXILL)
    Fitted; authors interpret both as roughly 0.5 solar, a key result.
  • Reflection fraction R = 0.7-1.3 (REFLIONX), 2.0-3.5 (RELXILL)
    Fitted; differs strongly between the two reflection models.
  • Ionisation parameter xi = 63+/-35 (REFLIONX), ~1000 (RELXILL)
    Fitted; the two reflection models disagree by an order of magnitude.
  • Narrow line energy E = 6.6-6.7 keV
    Fitted; identified as Fe XXV emission, required by all models.
assumptions (4)
  • domain assumption Relativistic reflection models RELXILL and REFLIONX accurately describe the disc reflection spectrum and atomic physics.
    The spin, inclination, and iron abundance constraints are only as reliable as these models; their disagreement on ionisation and reflection fraction shows model dependence.
  • domain assumption A flat first principal component of spectral variability indicates a single variable component's normalization.
    Used to favor blurred reflection; the paper notes multiple absorption zones can also produce a flat PCA (Section 4.5).
  • domain assumption Black hole spin, inclination, and iron abundance do not vary between 2001 and 2017.
    These parameters are tied across epochs in Section 4.4; if they vary, the constraints are smeared.
  • domain assumption The Galactic hydrogen column toward Mrk 478 is fixed at 1.08e20 cm^-2 from Willingale et al. (2013).
    Adopted as an external input for all fits; a wrong value would shift the continuum.

how reviews work

0 comments
Cite this review

Pith. "Pith review of Multi-epoch X-ray spectral analysis of the narrow-line Seyfert 1 galaxy Mrk 478." pith.science (2026). https://pith.science/paper/5ROCBTGP

@misc{pith2026190901897,
  author       = {Pith},
  title        = {Pith review of: Multi-epoch X-ray spectral analysis of the narrow-line Seyfert 1 galaxy Mrk 478},
  year         = {2026},
  howpublished = {\url{https://pith.science/paper/5ROCBTGP}},
  note         = {Machine review of arXiv:1909.01897}
}
read the original abstract

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-Comptonisation, and blurred reflection, to explain the observed spectral shape and variability over the 16 years. 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 ionisation and power law dominated spectrum, while relxill predicts a highly ionised and blurred reflection dominated spectrum. A power law dominated spectrum might be more consistent with the normal X-ray-to-UV spectral shape (aox). 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 keV likely attributable to Fe xxv emission, while no evidence for a narrow 6.4 keV line from neutral iron is detected.

Figures

Figures reproduced from arXiv: 1909.01897 by the authors.

Figure 1
Figure 1. Long term light curve between 1997 − 2017 for Mrk 478 with data from RXTE (black diamonds), Swift (green triangles), XMM-Newton (red circles) and Suzaku (blue squares). The 2−10 keV flux is shown on the y-axis, and the average flux is shown as a dashed black line. absorbed. However, the distribution on the expected αox is large (Vagnetti et al. 2013), so all values measured for Mrk 478 agree with one another and wit… view at source ↗
Figure 2
Figure 2. Top panel: Data from each epoch unfolded against a power law with Γ = 0. The shape of all spectra are comparable, with XMM4 and XMM5 being dimmer than other epochs. Bottom panel: Residuals from a power law fit from 2 − 4 and 7 − 10 keV, extrapolated over the 0.3 − 10 keV band. All data sets are fit with the average power law, and scaled by a constant to account for flux variations between observations. A strong soft… view at source ↗
Figure 3
Figure 3. Best-fit model and residuals for physical models in this work. Models are only shown for XMM5 for clarity. Top left: Model components and residuals for the partial covering scenario. Contributions from the intrinsic power law, ionised absorber, neutral absorber and total model are shown. Residuals (data/model) are shown in the panel below, displaying significant curvature at high and low energies. Top right: Model c… view at source ↗
Figures from the paper (6 more)
Figure 4
Figure 4. Figure 4: Correlations between best fit parameters using the partial covering model. While no linear trends are observable between data sets, the column density and covering fraction are higher for the dimmer flux XMM4 and XMM5 than for other data sets. free to vary, but kept li…
Figure 5
Figure 5. Figure 5: Correlations between best fit parameters using the Comptoni￾sation model. Clear correlations are present between all parameters, and changes between brighter and dimmer flux epochs are evident in all param￾eters [PITH_FULL_IMAGE:figures/full_fig_p009_5.png]
Figure 6
Figure 6. Figure 6: All available UVW1 and UVW2 data for all epochs compared to the a = 0 (dashed) and a = 0.998 (solid) best fit Comptonisation models. Colours and shapes match those of the corresponding X-ray data sets. Y￾axis error bars on the UV data are shown, but are smaller than th…
Figure 7
Figure 7. Figure 7: Correlations between best fit parameters using RELXILL (left) and REFLIONX (right). Although the error bars are large, REFLIONX shows more evidence for correlation between Fpl and Γ with ξ, and ξ and qin with R. Very little evidence for any correlations can be seen usi…
Figure 8
Figure 8. Figure 8: Comparison between the best fit spin, inclination and iron abun￾dance using RELXILL (blue) and REFLIONX (pink). Contours are shaded using 68, 90 and 99 percent of MCMC fits. The measured statistics, as well as the overall flatter shapes pro￾duced by the blurred reflect…
Figure 9
Figure 9. Figure 9: PCA using 20ks segments for all XMM-Newton observations (black). Only PC1 is significant, and accounts for 90 per cent of the vari￾ability. The shape is relatively flat, with some curvature around 4 − 7 keV. The PCA results from simulated data sets are also shown, with…

Discussion (0). Continue with ORCID to comment.

Forward citations

Cited by 1 Pith paper

Reviewed papers in the Pith corpus that reference this work. Sorted by Pith novelty score. OpenAlex reports about 19 citations worldwide. Full citation record

  1. The emergence of X-ray emission lines during relativistic radio-jet formation in the changing-look active galactic nucleus 1ES 1927+654

    astro-ph.HE 2026-07 conditional novelty 6.0 of 10

    X-ray emission lines and a broad iron feature emerged in changing-look AGN 1ES 1927+654 concurrently with radio-jet formation and declining ionized outflows from 2022 to 2025.

Reference graph

Works this paper leans on

77 extracted references · 15 canonical work pages · cited by 1 Pith paper

  1. [1]

    N., et al., 2019, @doi [ ] 10.1093/mnras/sty2527 , https://ui.adsabs.harvard.edu/abs/2019MNRAS.482.2088A 482, 2088

    Alston W. N., et al., 2019, @doi [ ] 10.1093/mnras/sty2527 , https://ui.adsabs.harvard.edu/abs/2019MNRAS.482.2088A 482, 2088

    doi:10.1093/mnras/sty2527 2019

  2. [2]

    Antonucci R., 1993, @doi [ ] 10.1146/annurev.aa.31.090193.002353 , https://ui.adsabs.harvard.edu/abs/1993ARA&A..31..473A 31, 473

    arXiv 1993

  3. [3]

    A., 1996, in Jacoby G

    Arnaud K. A., 1996, in Jacoby G. H., Barnes J., eds, Astronomical Society of the Pacific Conference Series Vol. 101, Astronomical Data Analysis Software and Systems V. p. 17

    1996

  4. [4]

    Bianchi S., Matt G., 2002, @doi [ ] 10.1051/0004-6361:20020372 , https://ui.adsabs.harvard.edu/abs/2002A&A...387...76B 387, 76

    work page doi:10.1051/0004-6361:20020372 2002

  5. [5]

    Boella G., et al., 1997, @doi [ ] 10.1051/aas:1997138 , https://ui.adsabs.harvard.edu/abs/1997A&AS..122..327B 122, 327

    work page doi:10.1051/aas:1997138 1997

  6. [6]

    N., Fink H., 1996, , https://ui.adsabs.harvard.edu/abs/1996A&A...305...53B 305, 53

    Boller T., Brandt W. N., Fink H., 1996, , https://ui.adsabs.harvard.edu/abs/1996A&A...305...53B 305, 53

    work page 1996

  7. [7]

    C., 2016, @doi [ ] 10.1093/mnras/stw466 , https://ui.adsabs.harvard.edu/abs/2016MNRAS.458.1927B 458, 1927

    Bonson K., Gallo L. C., 2016, @doi [ ] 10.1093/mnras/stw466 , https://ui.adsabs.harvard.edu/abs/2016MNRAS.458.1927B 458, 1927

    doi:10.1093/mnras/stw466 2016

  8. [8]

    C., Vasudevan R., 2015, @doi [ ] 10.1093/mnras/stv444 , https://ui.adsabs.harvard.edu/abs/2015MNRAS.450..857B 450, 857

    Bonson K., Gallo L. C., Vasudevan R., 2015, @doi [ ] 10.1093/mnras/stv444 , https://ui.adsabs.harvard.edu/abs/2015MNRAS.450..857B 450, 857

    work page doi:10.1093/mnras/stv444 2015

Show all 77 references
  1. [9]

    A., Green R

    Boroson T. A., Green R. F., 1992, @doi [ ] 10.1086/191661 , https://ui.adsabs.harvard.edu/abs/1992ApJS...80..109B 80, 109

    1992 doi

  2. [10]

    N., Fabian A

    Brandt W. N., Fabian A. C., Dotani T., Nagase F., Inoue H., Kotani T., Segawa Y., 1996, @doi [ ] 10.1093/mnras/283.3.1071 , https://ui.adsabs.harvard.edu/abs/1996MNRAS.283.1071B 283, 1071

    1996 doi

  3. [11]

    N., Mathur S., Elvis M., 1997, @doi [ ] 10.1093/mnras/285.3.L25 , https://ui.adsabs.harvard.edu/abs/1997MNRAS.285L..25B 285, L25

    Brandt W. N., Mathur S., Elvis M., 1997, @doi [ ] 10.1093/mnras/285.3.L25 , https://ui.adsabs.harvard.edu/abs/1997MNRAS.285L..25B 285, L25

    1997 doi

  4. [13]

    W., Reynolds C

    Brenneman L. W., Reynolds C. S., 2006, @doi [ ] 10.1086/508146 , https://ui.adsabs.harvard.edu/abs/2006ApJ...652.1028B 652, 1028

    2006 doi

  5. [14]

    N., et al., 2005, @doi [ ] 10.1007/s11214-005-5097-2 , https://ui.adsabs.harvard.edu/abs/2005SSRv..120..165B 120, 165

    Burrows D. N., et al., 2005, @doi [ ] 10.1007/s11214-005-5097-2 , https://ui.adsabs.harvard.edu/abs/2005SSRv..120..165B 120, 165

    2005 doi

  6. [15]

    Cash W., 1979, @doi [ ] 10.1086/156922 , https://ui.adsabs.harvard.edu/abs/1979ApJ...228..939C 228, 939

    1979 doi

  7. [16]

    S., Korista K., Ebrero J., Arav N., Kriss G., Steenbrugge K

    Costantini E., Kaastra J. S., Korista K., Ebrero J., Arav N., Kriss G., Steenbrugge K. C., 2010, @doi [ ] 10.1051/0004-6361/200912555 , https://ui.adsabs.harvard.edu/abs/2010A&A...512A..25C 512, A25

    2010 doi

  8. [17]

    W., Jin C., Blaes O., Ward M., 2012, @doi [ ] 10.1111/j.1365-2966.2011.19779.x , https://ui.adsabs.harvard.edu/abs/2012MNRAS.420.1848D 420, 1848

    Done C., Davis S. W., Jin C., Blaes O., Ward M., 2012, @doi [ ] 10.1111/j.1365-2966.2011.19779.x , https://ui.adsabs.harvard.edu/abs/2012MNRAS.420.1848D 420, 1848

    2012

  9. [18]

    Ehler H. J. S., Gonzalez A. G., Gallo L. C., 2018, @doi [ ] 10.1093/mnras/sty1306 , https://ui.adsabs.harvard.edu/abs/2018MNRAS.478.4214E 478, 4214

    2018 doi

  10. [19]

    A., et al., 2009, @doi [ ] 10.1111/j.1365-2966.2009.14913.x , https://ui.adsabs.harvard.edu/abs/2009MNRAS.397.1177E 397, 1177

    Evans P. A., et al., 2009, @doi [ ] 10.1111/j.1365-2966.2009.14913.x , https://ui.adsabs.harvard.edu/abs/2009MNRAS.397.1177E 397, 1177

    2009

  11. [20]

    C., Rees M

    Fabian A. C., Rees M. J., Stella L., White N. E., 1989, @doi [ ] 10.1093/mnras/238.3.729 , https://ui.adsabs.harvard.edu/abs/1989MNRAS.238..729F 238, 729

    1989 doi

  12. [23]

    C., Parker M

    Gallant D., Gallo L. C., Parker M. L., 2018, @doi [ ] 10.1093/mnras/sty1987 , https://ui.adsabs.harvard.edu/abs/2018MNRAS.480.1999G 480, 1999

    2018 doi

  13. [25]

    9-13 April 2018

    Gallo L., 2018, in Revisiting narrow-line Seyfert 1 galaxies and their place in the Universe. 9-13 April 2018. Padova Botanical Garden. p. 34 ( @eprint arXiv 1807.09838 )

    2018 arXiv

  14. [26]

    C., et al., 2015, @doi [ ] 10.1093/mnras/stu2108 , https://ui.adsabs.harvard.edu/abs/2015MNRAS.446..633G 446, 633

    Gallo L. C., et al., 2015, @doi [ ] 10.1093/mnras/stu2108 , https://ui.adsabs.harvard.edu/abs/2015MNRAS.446..633G 446, 633

    2015 doi

  15. [27]

    C., Randhawa J

    Gallo L. C., Randhawa J. S., Waddell S. G. H., Hani M. H., Garc \' a J. A., Reynolds C. S., 2019a, @doi [ ] 10.1093/mnras/stz260 , https://ui.adsabs.harvard.edu/abs/2019MNRAS.484.3036G 484, 3036

    doi

  16. [28]

    C., et al., 2019b, @doi [ ] 10.1093/mnras/stz274 , https://ui.adsabs.harvard.edu/abs/2019MNRAS.484.4287G 484, 4287

    Gallo L. C., et al., 2019b, @doi [ ] 10.1093/mnras/stz274 , https://ui.adsabs.harvard.edu/abs/2019MNRAS.484.4287G 484, 4287

    doi

  17. [29]

    S., Kallman T

    Garc \' a J., Dauser T., Reynolds C. S., Kallman T. R., McClintock J. E., Wilms J., Eikmann W., 2013, @doi [ ] 10.1088/0004-637X/768/2/146 , https://ui.adsabs.harvard.edu/abs/2013ApJ...768..146G 768, 146

    2013 doi

  18. [30]

    Garc \' a J., et al., 2014, @doi [ ] 10.1088/0004-637X/782/2/76 , https://ui.adsabs.harvard.edu/abs/2014ApJ...782...76G 782, 76

    2014 doi

  19. [31]

    Gehrels N., et al., 2004, @doi [ ] 10.1086/422091 , https://ui.adsabs.harvard.edu/abs/2004ApJ...611.1005G 611, 1005

    2004 doi

  20. [32]

    Goodman J., Weare J., 2010, @doi [Communications in Applied Mathematics and Computational Science] 10.2140/camcos.2010.5.65 , https://ui.adsabs.harvard.edu/abs/2010CAMCS...5...65G 5, 65

    2010 doi

  21. [33]

    W., 1989, @doi [ ] 10.1086/167586 , https://ui.adsabs.harvard.edu/abs/1989ApJ...342..224G 342, 224

    Goodrich R. W., 1989, @doi [ ] 10.1086/167586 , https://ui.adsabs.harvard.edu/abs/1989ApJ...342..224G 342, 224

    1989 doi

  22. [34]

    A., Heckman T

    Groves B. A., Heckman T. M., Kauffmann G., 2006, @doi [ ] 10.1111/j.1365-2966.2006.10812.x , https://ui.adsabs.harvard.edu/abs/2006MNRAS.371.1559G 371, 1559

    2006

  23. [35]

    C., Beuermann K., 2001, @doi [ ] 10.1051/0004-6361:20000429 , https://ui.adsabs.harvard.edu/abs/2001A&A...367..470G 367, 470

    Grupe D., Thomas H. C., Beuermann K., 2001, @doi [ ] 10.1051/0004-6361:20000429 , https://ui.adsabs.harvard.edu/abs/2001A&A...367..470G 367, 470

    2001 doi

  24. [36]

    M., 2010, in Maraschi L., Ghisellini G., Della Ceca R., Tavecchio F., eds, Astronomical Society of the Pacific Conference Series Vol

    Grupe D., Komossa S., Leighly K. M., 2010, in Maraschi L., Ghisellini G., Della Ceca R., Tavecchio F., eds, Astronomical Society of the Pacific Conference Series Vol. 427, Accretion and Ejection in AGN: a Global View. p. 86

    2010

  25. [37]

    Guainazzi M., Loiseau N., Matt G., Orr A., 2004, @doi [Progress of Theoretical Physics Supplement] 10.1143/PTPS.155.243 , https://ui.adsabs.harvard.edu/abs/2004PThPS.155..243G 155, 243

    2004 doi

  26. [38]

    Jansen F., et al., 2001, @doi [ ] 10.1051/0004-6361:20000036 , https://ui.adsabs.harvard.edu/abs/2001A&A...365L...1J 365, L1

    2001 doi

  27. [39]

    S., Bleeker J

    Kaastra J. S., Bleeker J. A. M., 2016, @doi [ ] 10.1051/0004-6361/201527395 , https://ui.adsabs.harvard.edu/abs/2016A&A...587A.151K 587, A151

    2016 doi

  28. [40]

    M., 1999, @doi [ ] 10.1086/313287 , https://ui.adsabs.harvard.edu/abs/1999ApJS..125..317L 125, 317

    Leighly K. M., 1999, @doi [ ] 10.1086/313287 , https://ui.adsabs.harvard.edu/abs/1999ApJS..125..317L 125, 317

    1999 doi

  29. [41]

    L., Edelson R

    Marshall H. L., Edelson R. A., Vaughan S., Malkan M., O'Brien P., Warwick R., 2003, @doi [ ] 10.1086/345820 , https://ui.adsabs.harvard.edu/abs/2003AJ....125..459M 125, 459

    2003 doi

  30. [42]

    O., et al., 2001, @doi [ ] 10.1051/0004-6361:20000044 , https://ui.adsabs.harvard.edu/abs/2001A&A...365L..36M 365, L36

    Mason K. O., et al., 2001, @doi [ ] 10.1051/0004-6361:20000044 , https://ui.adsabs.harvard.edu/abs/2001A&A...365L..36M 365, L36

    2001 doi

  31. [43]

    Mathur S., 2000, @doi [ ] 10.1046/j.1365-8711.2000.03530.x , https://ui.adsabs.harvard.edu/abs/2000MNRAS.314L..17M 314, L17

    2000

  32. [44]

    C., Ross R

    Matt G., Fabian A. C., Ross R. R., 1996, @doi [ ] 10.1093/mnras/278.4.1111 , https://ui.adsabs.harvard.edu/abs/1996MNRAS.278.1111M 278, 1111

    1996 doi

  33. [45]

    J., Reeves J

    Miller L., Turner T. J., Reeves J. N., 2008, @doi [ ] 10.1051/0004-6361:200809590 , https://ui.adsabs.harvard.edu/abs/2008A&A...483..437M 483, 437

    2008 doi

  34. [47]

    Mitsuda K., et al., 2007, @doi [ ] 10.1093/pasj/59.sp1.S1 , https://ui.adsabs.harvard.edu/abs/2007PASJ...59S...1M 59, S1

    2007 doi

  35. [48]

    Miyakawa T., Ebisawa K., Inoue H., 2012, @doi [ ] 10.1093/pasj/64.6.140 , https://ui.adsabs.harvard.edu/abs/2012PASJ...64..140M 64, 140

    2012 doi

  36. [49]

    arXiv:1306.2307

    Nandra K., et al., 2013, arXiv e-prints, https://ui.adsabs.harvard.edu/abs/2013arXiv1306.2307N p. arXiv:1306.2307

    2013 arXiv

  37. [50]

    A., et al., 2011, @doi [ ] 10.1088/0004-637X/728/1/13 , https://ui.adsabs.harvard.edu/abs/2011ApJ...728...13N 728, 13

    Nowak M. A., et al., 2011, @doi [ ] 10.1088/0004-637X/728/1/13 , https://ui.adsabs.harvard.edu/abs/2011ApJ...728...13N 728, 13

    2011 doi

  38. [51]

    Oh K., et al., 2018, @doi [ ] 10.3847/1538-4365/aaa7fd , https://ui.adsabs.harvard.edu/abs/2018ApJS..235....4O 235, 4

    2018 doi

  39. [52]

    E., Pogge R

    Osterbrock D. E., Pogge R. W., 1985, @doi [ ] 10.1086/163513 , https://ui.adsabs.harvard.edu/abs/1985ApJ...297..166O 297, 166

    1985 doi

  40. [53]

    L., Walton D

    Parker M. L., Walton D. J., Fabian A. C., Risaliti G., 2014, @doi [ ] 10.1093/mnras/stu712 , https://ui.adsabs.harvard.edu/abs/2014MNRAS.441.1817P 441, 1817

    2014 doi

  41. [54]

    L., et al., 2015, @doi [ ] 10.1093/mnras/stu2424 , https://ui.adsabs.harvard.edu/abs/2015MNRAS.447...72P 447, 72

    Parker M. L., et al., 2015, @doi [ ] 10.1093/mnras/stu2424 , https://ui.adsabs.harvard.edu/abs/2015MNRAS.447...72P 447, 72

    2015 doi

  42. [55]

    R., Reeves J

    Patrick A. R., Reeves J. N., Porquet D., Markowitz A. G., Braito V., Lobban A. P., 2012, @doi [ ] 10.1111/j.1365-2966.2012.21868.x , https://ui.adsabs.harvard.edu/abs/2012MNRAS.426.2522P 426, 2522

    2012

  43. [56]

    Ponti G., et al., 2010, @doi [ ] 10.1111/j.1365-2966.2010.16852.x , https://ui.adsabs.harvard.edu/abs/2010MNRAS.406.2591P 406, 2591

    2010

  44. [57]

    N., O'Brien P., Brinkmann W., 2004, @doi [ ] 10.1051/0004-6361:20047108 , https://ui.adsabs.harvard.edu/abs/2004A&A...422...85P 422, 85

    Porquet D., Reeves J. N., O'Brien P., Brinkmann W., 2004, @doi [ ] 10.1051/0004-6361:20047108 , https://ui.adsabs.harvard.edu/abs/2004A&A...422...85P 422, 85

    2004 doi

  45. [58]

    Porquet D., et al., 2018, @doi [ ] 10.1051/0004-6361/201731290 , https://ui.adsabs.harvard.edu/abs/2018A&A...609A..42P 609, A42

    2018 doi

  46. [59]

    S., Fabian A

    Reynolds C. S., Fabian A. C., Brenneman L. W., Miniutti G., Uttley P., Gallo L. C., 2009, @doi [ ] 10.1111/j.1745-3933.2009.00676.x , https://ui.adsabs.harvard.edu/abs/2009MNRAS.397L..21R 397, L21

    2009

  47. [60]

    Rivers E., Markowitz A., Rothschild R., 2013, @doi [ ] 10.1088/0004-637X/772/2/114 , https://ui.adsabs.harvard.edu/abs/2013ApJ...772..114R 772, 114

    2013 doi

  48. [61]

    R., Fabian A

    Ross R. R., Fabian A. C., 2005, @doi [ ] 10.1111/j.1365-2966.2005.08797.x , https://ui.adsabs.harvard.edu/abs/2005MNRAS.358..211R 358, 211

    2005

  49. [62]

    R., Fabian A

    Ross R. R., Fabian A. C., Young A. J., 1999, @doi [ ] 10.1046/j.1365-8711.1999.02528.x , https://ui.adsabs.harvard.edu/abs/1999MNRAS.306..461R 306, 461

    1999

  50. [63]

    G., 1997, @doi [ ] 10.1086/303829 , https://ui.adsabs.harvard.edu/abs/1997ApJ...478..522S 478, 522

    Skibo J. G., 1997, @doi [ ] 10.1086/303829 , https://ui.adsabs.harvard.edu/abs/1997ApJ...478..522S 478, 522

    1997 doi

  51. [64]

    Str \"u der L., et al., 2001, @doi [ ] 10.1051/0004-6361:20000066 , https://ui.adsabs.harvard.edu/abs/2001A&A...365L..18S 365, L18

    2001 doi

  52. [65]

    S., 1994, , https://ui.adsabs.harvard.edu/abs/1994PASJ...46L..37T 46, L37

    Tanaka Y., Inoue H., Holt S. S., 1994, , https://ui.adsabs.harvard.edu/abs/1994PASJ...46L..37T 46, L37

    1994

  53. [66]

    Tanaka Y., Ueda Y., Boller T., 2003, @doi [ ] 10.1046/j.1365-8711.2003.06110.x , https://ui.adsabs.harvard.edu/abs/2003MNRAS.338L...1T 338, L1

    2003

  54. [67]

    Tanaka Y., Boller T., Gallo L., Keil R., Ueda Y., 2004, @doi [ ] 10.1093/pasj/56.3.L9 , https://ui.adsabs.harvard.edu/abs/2004PASJ...56L...9T 56, L9

    2004 doi

  55. [68]

    Tananbaum H., et al., 1979, @doi [ ] 10.1086/183100 , https://ui.adsabs.harvard.edu/abs/1979ApJ...234L...9T 234, L9

    1979 doi

  56. [69]

    Tashiro M., et al., 2018, in . p. 1069922, @doi 10.1117/12.2309455

    2018 doi

  57. [70]

    Tripathi S., Waddell S. G. H., Gallo L. C., Welsh W. F., Chiang C.-Y., 2019, arXiv e-prints, https://ui.adsabs.harvard.edu/abs/2019arXiv190707048T p. arXiv:1907.07048

    2019 arXiv

  58. [71]

    J., Miller L., 2010, @doi [ ] 10.1088/0004-637X/709/2/1230 , https://ui.adsabs.harvard.edu/abs/2010ApJ...709.1230T 709, 1230

    Turner T. J., Miller L., 2010, @doi [ ] 10.1088/0004-637X/709/2/1230 , https://ui.adsabs.harvard.edu/abs/2010ApJ...709.1230T 709, 1230

    2010 doi

  59. [72]

    Turner M. J. L., et al., 2001, @doi [ ] 10.1051/0004-6361:20000087 , https://ui.adsabs.harvard.edu/abs/2001A&A...365L..27T 365, L27

    2001 doi

  60. [73]

    M., Padovani P., 1995, @doi [ ] 10.1086/133630 , https://ui.adsabs.harvard.edu/abs/1995PASP..107..803U 107, 803

    Urry C. M., Padovani P., 1995, @doi [ ] 10.1086/133630 , https://ui.adsabs.harvard.edu/abs/1995PASP..107..803U 107, 803

    1995 doi

  61. [74]

    Vagnetti F., Antonucci M., Trevese D., 2013, @doi [ ] 10.1051/0004-6361/201220443 , https://ui.adsabs.harvard.edu/abs/2013A&A...550A..71V 550, A71

    2013 doi

  62. [75]

    C., Ballantyne D

    Vaughan S., Fabian A. C., Ballantyne D. R., De Rosa A., Piro L., Matt G., 2004, @doi [ ] 10.1111/j.1365-2966.2004.07769.x , https://ui.adsabs.harvard.edu/abs/2004MNRAS.351..193V 351, 193

    2004

  63. [76]

    C., Brinkman B., Canizares C., Garmire G., Murray S., Van Speybroeck L

    Weisskopf M. C., Brinkman B., Canizares C., Garmire G., Murray S., Van Speybroeck L. P., 2002, @doi [ ] 10.1086/338108 , https://ui.adsabs.harvard.edu/abs/2002PASP..114....1W 114, 1

    2002 doi

  64. [77]

    R., Gallo L

    Wilkins D. R., Gallo L. C., Grupe D., Bonson K., Komossa S., Fabian A. C., 2015, @doi [ ] 10.1093/mnras/stv2130 , https://ui.adsabs.harvard.edu/abs/2015MNRAS.454.4440W 454, 4440

    2015 doi

  65. [78]

    R., Gallo L

    Wilkins D. R., Gallo L. C., Silva C. V., Costantini E., Brandt W. N., Kriss G. A., 2017, @doi [ ] 10.1093/mnras/stx1814 , https://ui.adsabs.harvard.edu/abs/2017MNRAS.471.4436W 471, 4436

    2017 doi

  66. [79]

    Willingale R., Starling R. L. C., Beardmore A. P., Tanvir N. R., O'Brien P. T., 2013, @doi [ ] 10.1093/mnras/stt175 , https://ui.adsabs.harvard.edu/abs/2013MNRAS.431..394W 431, 394

    2013 doi

  67. [80]

    Wilms J., Allen A., McCray R., 2000, @doi [ ] 10.1086/317016 , https://ui.adsabs.harvard.edu/abs/2000ApJ...542..914W 542, 914

    2000 doi

  68. [81]

    C., Gallo L

    Zoghbi A., Fabian A. C., Gallo L. C., 2008, @doi [ ] 10.1111/j.1365-2966.2008.14078.x , https://ui.adsabs.harvard.edu/abs/2008MNRAS.391.2003Z 391, 2003

    2008

  69. [82]

    W., et al., 2001, @doi [ ] 10.1051/0004-6361:20000058 , https://ui.adsabs.harvard.edu/abs/2001A&A...365L...7D 365, L7

    den Herder J. W., et al., 2001, @doi [ ] 10.1051/0004-6361:20000058 , https://ui.adsabs.harvard.edu/abs/2001A&A...365L...7D 365, L7

    2001 doi

Pith tools

Reviewed August 14, 2026 · model on record in the stance chip above.