Pith. sign in

REVIEW 3 major objections 5 minor 1 cited by

XRISM analysis of the complex Fe K$\alpha$ line in Centaurus A

T0 review · 3 major / 5 minor · reviewed 2026-08-06 · deepseek-v4-flash

Pith's one-line read The Fe Kα line in Centaurus A demands an emission region spanning roughly 0.001 to 10 parsecs.

desk verdict Resolved Fe Kα doublet and a broad component in Cen A are real and worth knowing; the q≈2 extended-emission interpretation rests on a model combination the authors themselves admit is inconsistent. read the letter →

arxiv 2507.02195 v1 pith:Z5D7PM52 submitted 2025-07-02 astro-ph.HE astro-ph.GA

classification astro-ph.HEastro-ph.GA
keywords activegalacticnucleiX-rayspectroscopyFeKalphaCentaurusAXRISM/Resolveemissivityindexreverberationmappingbroad-lineregion
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

Using the high-resolution XRISM/Resolve spectrum of the nearest active galactic nucleus, the paper shows that the Fe Kα line is not a single narrow feature but a resolved doublet with FWHM of about 480 km/s sitting on a broad component with FWHM of about 4300 km/s and comparable flux. The authors argue that this line shape can only be produced by an emission region extending from about $10^{-3}$ pc to about $10^{1}$ pc, with emissivity falling as $r^{-q}$ and $q\approx 1.99$. If correct, this is one of the first direct measurements of an AGN line-emitting region spanning four orders of magnitude in radius, from the broad-line-region scale to the torus or molecular-disk scale. The fits also favor a low inclination of about $24^{\circ}$, consistent with the jet orientation, rather than the high inclination implied by the Seyfert-2 classification.

What carries the argument

The load-bearing ingredients are the laboratory Fe Kα1/Kα2 line shape (energies, widths, and 2:1 intensity ratio), the roughly 5 eV resolution of the XRISM/Resolve microcalorimeter at 7 keV that separates the doublet and the broad wings, and the composite spectral model rdblur * MYTorusL. In that model, MYTorusL supplies a pre-broadened toroidal line profile including the Compton shoulder, while rdblur applies Doppler and relativistic blurring for a disk surface between an inner and outer radius with radial emissivity $\epsilon(r)\propto r^{-q}$. Model comparisons use the C-statistic for fitting and the Bayesian information criterion for penalizing extra components, and a multiplicative constant $k$ absorbs delays, abundances, and geometry differences between the assumed and true reprocessor.

What would settle it

A decisive test would be a fully self-consistent model that applies relativistic kinematics and ray tracing in situ to an extended toroidal reprocessor: if such a model fits the same XRISM/Resolve spectrum with $q=3$ or with a different radial extent, the paper's core claims would fail. A simpler check is whether the broad 4300 km/s component survives a re-fit with an independently recalibrated Resolve line-spread function; removing that component would collapse the argument for emission out to tens of parsecs.

Watch

Extended reading notes

Core claim

The paper's central claim is that the Fe Kα complex of Centaurus A contains a narrow doublet and a broad base whose combined profile requires a radially extended, roughly uniform reprocessor. Two narrow peaks at the laboratory energies of Fe Kα1 and Fe Kα2 are resolved with FWHM $(4.8\pm0.2)\times10^2$ km/s each, while a broad component with FWHM $(4.3\pm0.3)\times10^3$ km/s carries a similar flux. Modelling the line with a blurred toroidal-reprocessor profile (rdblur applied to MYTorusL), the authors find a best fit with inner radius $5.4^{+7.8}_{-4.0}\times10^2\,r_g$ ($1.4^{+2.1}_{-1.1}\times10^{-3}$ pc) and outer radius $6.6^{+13.8}_{-3.2}\times10^6\,r_g$ ($17^{+36}_{-9}$ pc), emissivity index $q=1.99\pm0.03$, and inclination $24^{+13}_{-7}$ degrees. If $q$ is fixed to the commonly assumed value of 3, the same line profile can only be reproduced with three separate emitting components, which the authors take as evidence that the fitted $q\approx2$ is intrinsic rather than an artifact of one parameterization.

Load-bearing premise

The inferred radial extent, $q\approx2$, and inclination assume that stacking rdblur (which treats the pre-blurred line as emitted at a single radius) on top of MYTorusL (which computes the line from an extended torus) does not seriously bias the fit, an inconsistency the authors themselves flag as potentially offsetting some best-fit parameters.

Editorial extensions

If this is right

  • If $q\approx2$ is real, the ionizing corona must be extended, or the reprocessor must bend so that the illuminating flux does not decay as fast as $r^{-2}$, changing standard assumptions about AGN disk-corona geometry.
  • The fitted outer radius of roughly 10 pc puts the outer line-emitting region within reach of ALMA or JWST, offering an independent, spatially resolved test of the spectral fit.
  • The absence of a comparably broad component in optical and infrared lines implies that the broad Fe Kα emission traces gas that is hidden, dust-free, or otherwise invisible at longer wavelengths.
  • The low inclination of about $24^{\circ}$ agrees with jet and inner-disk measurements and implies that Cen A's Seyfert-2 appearance comes from line-of-sight obscuration rather than an edge-on disk.
  • The result extends to a second object the pattern seen in NGC 4151, where the Fe Kα line also required emission from multiple radii, suggesting such complex line profiles may be common in nearby AGNs.

Reading between the lines

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

  • A direct testable extension is that other nearby AGNs observed with XRISM/Resolve should show similar narrow-doublet-plus-broad profiles with $q\approx2$ if an extended corona is the norm rather than a lamppost.
  • The large normalization factor $k\approx4$ could be a delayed response of the line to a brighter past continuum; a monitoring campaign tracking line flux and continuum simultaneously would test whether variability alone explains it.
  • The apparent ring-like inner component described in the appendix, if confirmed, could be a tidally disrupted structure; searching for similar narrow radial annuli in other high-resolution AGN spectra would provide a test.
  • Fitting the Fe Kβ line and the broad-band continuum, as the authors indicate they plan to do with NuSTAR and XRISM/Xtend, could break the degeneracy among $q$, inclination, and $k$ that limits the present fits.
Share X Bluesky LinkedIn Reddit HN

Editorial analysis

A structured set of objections, weighed in public.

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

Referee Report

3 major / 5 minor

Summary. The paper analyzes the Fe Kα complex in Cen A using the first XRISM/Resolve spectrum, with a Chandra-based estimate of contaminating emission within the XRISM beam. The authors report that the line consists of narrow Fe Kα1/α2 cores with FWHM ≈ 480 km/s plus a broad component with FWHM ≈ 4300 km/s of comparable flux. They then fit the 6.0–6.8 keV band with phenomenological Gaussians and with several combinations of the MYTorusL reprocessor table model blurred by the rdblur disk-blurring kernel. The preferred single-component model (model A) yields an emissivity index q = 1.99 ± 0.03, inner radius ≈ 5.4×10^2 r_g, outer radius ≈ 6.6×10^6 r_g, and inclination 24+13−7 deg, but requires a relative normalization k = 4.1. Alternative models with two or three components, with reverberation-mapping radius priors, and with fixed q = 3 are also explored. The paper concludes that the line shape requires an extended emission region from ~10^−3 pc to ~10 pc and that q ≈ 2.

Significance. If the q ≈ 2 result and the derived radial extent are robust, the paper would provide a rare, high-resolution X-ray constraint on the location of Fe Kα-emitting gas in a nearby AGN, with implications for coronal geometry and the relationship between the X-ray and optical/IR line-emitting structures. The observational work is careful in several respects: the broad-line detection is supported by clear residuals in the two-Gaussian fit (Fig. 3) and by BIC comparisons; the contamination subtraction using simultaneous Chandra data is a strength; and the authors explicitly enumerate the model caveats in Sections 3.2 and 4. However, the central astrophysical inference — that a single emission region with q ≈ 2 extending over four decades in radius is required — rests on the rdblur*MYTorusL convolution, a model combination the paper itself describes as internally inconsistent. In its current form the paper does not establish the q ≈ 2 claim beyond the model's assumptions, so the significance of the headline result is not yet realized.

major comments (3)
  1. [Section 3.2, model A and Table 2] The central claim that the Fe Kα line requires an emission region extending from ~10^−3 pc to ~10 pc with emissivity index q = 1.99 ± 0.03 is derived from convolving the MYTorusL line profile with rdblur. As the authors themselves note in Section 3.2 and again in Section 4, rdblur assumes the pre-blurred line is emitted at a single radius, whereas MYTorusL produces a line from an extended toroidal reprocessor so that 'the information about the location from which the Fe Kα photons were emitted in the MYTorusL model is lost'. In the Compton-thin regime relevant here, the unblurred MYTorusL line is close to the narrow 2:1 laboratory doublet, so the broad-to-narrow flux ratio and the line wings are essentially set by the assumed r^−q emissivity law in rdblur. The quoted ±0.03 uncertainty is therefore purely statistical and does not include the dominant model systematic. The q ≈ 2 conclusion is not established until it is recovered from a model that computes the Fe Kα line emissivity and Doppler/relativistic kinematics self-consistently (e.g., a Monte Carlo reprocessor with an explicit radial emissivity), or until the authors quantify the bias in q, Rin, and Rout caused by the single-radius assumption, for example by fitting simulated spectra generated with a known emissivity law.
  2. [Section 3.2, relative normalization k = 4.1] Model A requires a relative normalization k = 4.1+6.0−1.3, and the authors' own variability estimate based on the Swift/BAT light curve (Section 3.2 and Fig. 5) accounts for only a factor 2.3 ± 0.8 of this offset. This means that at k = 1 the MYTorusL line flux is significantly underpredicted, and the model is not a self-consistent physical description of both the line shape and the line normalization. Because the radial emissivity inference is drawn from the same model, the large k signals a mismatch between the assumed reprocessor and the actual emitting region, further weakening the q ≈ 2 claim. The paper lists possible explanations (past variability, non-solar abundances, geometry differences), but these are not tested; the revision should either remove the k-unity physical interpretation, add an explicit caveat that q is derived from a model whose normalization is ad hoc, or demonstrate with a concrete test that the normalization deficit does not bias q.
  3. [Section 5, first paragraph] The statement that 'the Fe Kα line in Cen A has a complex shape, which can only be explained by contribution from emission regions distributed over a wide range of radii, from ∼10^2−3 r_g ∼ 10^−3 pc to >∼10^6 r_g, which corresponds to >∼10 pc' is too strong given the acknowledged model inconsistencies of model A and the fact that the paper itself shows an alternative model (model D, with q = 3) that reproduces the profile with three components, not a single continuous radial distribution. The data robustly require a broad line, but the specific radial extent and especially the continuous extended region are model-dependent. The conclusions should be rephrased to say that the line shape is consistent with, but does not uniquely require, a single extended region with q ≈ 2, and the systematic uncertainty from the rdblur*MYTorusL combination should be reflected in the abstract and conclusions.
minor comments (5)
  1. [Section 3.1] The statement that 'Additional Gaussian profiles only provided minimal improvements in the fit statistic and were ruled out as necessary components of the line profile by the BIC' is not quantified; please report the C-statistic and BIC values for the models with one, two, three, and four Gaussian components, or state that they are available as supplementary material.
  2. [Table 2] Several entries in Table 2 are ambiguous because a missing lower or upper error is not explicitly flagged; for example, model C lists Rin = 5.7+4.5 × 10^4 r_g with no lower error, and model D lists Rout = 8.3 × 10^8 r_g with no errors at all. Please add a systematic notation, such as a footnote stating that a missing bound means the parameter is unconstrained in that direction.
  3. [Section 2.3 and Section 3.2] The paper states in Section 2.3 that all parameters are presented with 1σ uncertainties, but in Section 3.2 the black hole mass error is quoted as a 3σ error and then rescaled; please clarify the convention at the first use of uncertainties (including asymmetric errors) so the reader knows which quantities are 1σ and which are not.
  4. [Section 3.2] The notation 'rdblur * atable{mytl_V000HLZnEp000_v01.fits}' is difficult to parse in prose; after the first use, please define a shorthand name (e.g., 'the MYTorusL table model') and then use that shorthand consistently throughout the text.
  5. [Fig. 5 caption] The caption sentence 'The 4.1+6.0−1.3 multiple of that is depicted as a dashed line' is grammatically incomplete and unclear; please specify that the dashed line is the average BAT count rate multiplied by the best-fit relative normalization k, and that the pink region is the corresponding 1σ range.

Circularity Check

0 steps flagged · score 1.0 of 10

No significant circularity: q≈2, the 10^-3–10 pc radial extent, and the ~24° inclination are free parameters fitted to the XRISM/Resolve spectrum and reported as fit results; the paper's own caveats disclose model-mismatch risks that are correctness concerns, and the author-overlapping inputs (MYTorusL, reverberation lags) are independently falsifiable.

full rationale

Finding: no significant circularity, at the low end (score 1). This is an observational spectral-fitting paper: every headline quantity is a free parameter fitted to the XRISM/Resolve data and presented as a fit result, not as an independent prediction. The broad Fe Kα component is first required by a phenomenological three-Gaussian fit, with the residuals of a two-Gaussian fit shown to demonstrate the need for a broad line (Section 3.1); this is a data requirement independent of any reprocessor model. The values q = 1.99 ± 0.03, Rin ≈ 5.4 × 10^2 rg, Rout ≈ 6.6 × 10^6 rg, and i = 24+13/−7 deg are parameters of rdblur*MYTorusL that were allowed to vary freely ('We allowed the inner radius, outer radius, inclination, and emissivity index to vary freely'), so the 'extended emission region' claim is a restatement of the fitted radii driven by the data, not a value imposed by the model. The q = 3 fixed case is shown to require three components (model D), which is a genuine model comparison, not a foregone conclusion. The main modeling weakness is disclosed by the authors themselves: the rdblur model 'assumes that the pre-convolved line shape is emitted at a single radius,' while the MYTorusL line is generated by an extended torus, and the authors warn that 'these inconsistencies may bias some results and offset some of the best-fit spectral parameters from their true values' (Section 3.2). This acknowledged model-mismatch is a correctness/bias risk, not a circular step. The many author-overlapping citations do not create circularity: MYTorusL (Murphy & Yaqoob 2009; Yaqoob 2024) is an externally published Monte Carlo reprocessor whose line shapes are falsifiable, and indeed the fit forces a normalization k = 4.1+6.0/−1.3 that exceeds the variability ratio of 2.3 ± 0.8, showing the model's prediction was tested and found deficient rather than being self-fulfilling. The reverberation radii of Iwata et al. (2024) come from independent Swift/BAT lag measurements and are found insufficient to reproduce the line profile without an added inner component (model C), an independent cross-check rather than a conclusion forced by its inputs. Bogensberger et al. (2024a,b) and XRISM Collaboration et al. (2024) are cited for context and comparison, not as premises of the Cen A conclusion.

Assumptions & free parameters 6 free parameters · 5 assumptions · 1 invented entities

The physical interpretation rests on the fitted parameters q, Rin, Rout, i, k, and NH in the rdblur * MYTorusL framework, plus the assumption that this framework is valid. The conversion to parsecs depends on externally measured black hole mass and distance. The inner ring-like structure in Appendix 1 is an ad hoc model component without independent evidence. No new fundamental entities are introduced.

free parameters (6)
  • Emissivity index q = 1.99 +/- 0.03 (model A); 2.08+0.06-0.07 (model B); 2.2 +/- 0.2 (model C)
    The central physical result. It is fitted freely, not predicted, and it drives the interpretation of an extended corona or non-uniform density.
  • Inner radius Rin = 5.4e2 rg, or 1.4e-3 pc (model A)
    Fitted; sets the inner edge of the claimed extended line-emitting region.
  • Outer radius Rout = 6.6e6 rg, or 17 pc (model A)
    Fitted; sets the outer edge of the claimed extended line-emitting region.
  • Inclination i = 24+13-7 degrees (model A)
    Fitted; used to compare with jet and molecular disk inclinations.
  • Relative normalization k = 4.1+6.0-1.3 (model A)
    Fitted; a large value that is not independently explained and may indicate model deficiency or long-term variability.
  • MYTorusL equatorial NH = 0.10e24 cm^-2 (model A)
    Fitted; degenerate with the relative normalization k and affects the line flux.
assumptions (5)
  • domain assumption Fe Kalpha emissivity follows a single power law in radius, epsilon(r) proportional to r^-q, over the whole emitting region.
    Used by rdblur in all models A through D. The conclusion q about 2 is this parameter, so the power-law shape is assumed, not derived.
  • domain assumption MYTorusL's assumed geometry (torus with a 60 degree opening angle), Hölzer intrinsic line profiles, and solar abundances represent the true reprocessor.
    The paper uses MYTorusL 'for lack of a more realistic model' and notes that opening angle differences could affect normalizations.
  • ad hoc to paper The rdblur single-radius kinematic blurring can be applied after the fact to the MYTorusL extended-torus line profile.
    Admitted inconsistency in Section 3.2: rdblur assumes emission at a single radius while MYTorusL's line carries no radius information. This is load-bearing for all physical parameter inferences.
  • domain assumption The black hole mass of 5.5e7 Msun (Cappellari et al. 2009; Koss et al. 2022) and distance of 3.8 Mpc are correct for converting rg to pc.
    All radial extents in parsecs and comparisons to reverberation-mapping radii depend on this conversion.
  • domain assumption The local continuum (absorbed power law plus Fe XXV lines) and the Chandra-derived contaminating source model are accurate in the 6.0 to 6.8 keV band.
    The paper fits a narrow band and notes the fitted NH and Gamma are 'not consistent with the broad-band X-ray spectrum,' so the continuum under the line is an approximation.
invented entities (1)
  • Inner narrow ring-like Fe Kalpha emitting structure at about 8.2e2 rg
    purpose: Fits residual deviations at both ends of the Fe Kalpha broad wings in the Appendix 1 model.
    The paper states 'It is unclear if this inner narrow-ring-like structure exists, and its required physical parameters are questionable.' It is introduced ad hoc to improve the C-statistic and is not statistically preferred over model A.

how reviews work

0 comments
Cite this review

Pith. "Pith review of XRISM analysis of the complex Fe K$\alpha$ line in Centaurus A." pith.science (2026). https://pith.science/paper/Z5D7PM52

@misc{pith2026250702195,
  author       = {Pith},
  title        = {Pith review of: XRISM analysis of the complex Fe K$\alpha$ line in Centaurus A},
  year         = {2026},
  howpublished = {\url{https://pith.science/paper/Z5D7PM52}},
  note         = {Machine review of arXiv:2507.02195}
}
abstract

We analyze the high-resolution XRISM/Resolve spectrum of the Fe K$\alpha$ emission line of the nearest active galactic nucleus, in Centaurus A. The line features two narrow and resolved peaks of Fe K$\alpha_1$, and Fe K$\alpha_2$ with a FWHM of $(4.8\pm0.2)\times10^2$ km/s each. A broad line with a FWHM of $(4.3\pm0.3)\times10^3$ km/s, and with a flux similar to the two narrow line cores, is also required. This broad component is not observed in the optical or IR spectra of Cen A. The line shape requires the existence of an emission region that extends from $\sim10^{-3}$ pc to $\sim10^1$ pc. Assuming that the emissivity follows a radial power-law profile of $r^{-q}$, we find $q\approx2$. This may indicate an extended corona, an emitting region that bends towards the corona, or a non-uniform density. When assuming $q=3$, the line shape can only be reproduced by including three emitting components in the model. The measured best-fit inclination is $24^{+13}_{-7}$ degrees, but higher inclinations are only slightly disfavored. A single blurred MYTorusL line profile can describe the line shape, but requires a large relative normalization. This could be due to past variability, modified abundances, or differing geometries. The line shape can be reproduced from the radii measured by reverberation mapping, but only if an additional extended emitting region at small radii is included.

Figures

Figures reproduced from arXiv: 2507.02195 by the authors.

Figure 1
Figure 1. Chandra image of Cen A in observation 29490. The green annulus has inner and outer radii of 5 ′′ and 76′′, and depicts the source extrac￾tion region to determine the spectrum of the contaminating sources in the XRISM/Resolve spectrum. The background extraction region is indicated as a rectangle. Individual pixels are colored according to the number of counts in them, with the color bar covering the interval of 0 to … view at source ↗
Figure 2
Figure 2. Chandra spectrum of the contaminating X-ray sources which can￾not be resolved from the nuclear spectrum observed by XRISM/Resolve. The spectrum is best fitted with a power-law model. Alt text: Plot depicting the background-subtracted source spectrum, as well as the background spectrum of the contaminating X-ray sources. The best-fitting power-law model used to fit the source spectrum is shown as well. a 2−10 keV flu… view at source ↗
Figure 3
Figure 3. [PITH_FULL_IMAGE:figures/full_fig_p005_3.png] view at source ↗
Figures from the paper (4 more)
Figure 4
Figure 4. Figure 4: XRISM/Resolve spectrum of the Fe Kα line, fitted with model A, featuring one MYTorusL line model, an emissivity index that is free to vary, and a constant normalization scaling factor. This figure depicts the best fit in the 6.24 − 6.52 keV energy range. The spectrum w…
Figure 6
Figure 6. Figure 6: XRISM/Resolve spectrum of the Fe Kα line, fitted with model B; two MYTorusL line models and an emissivity index that is free to vary. Alt text: Figure of the fitted spectrum, and the ratio of the difference between data and model, and the error of each data point. The …
Figure 7
Figure 7. Figure 7: XRISM/Resolve spectrum of the Fe Kα line, fitted with model C; three MYTorusL components and an emissivity index that is free to vary, but the radii set equal to those found from reverberation mapping by Iwata et al. (2024). Alt text: Figure of the fitted spectrum, and…
Figure 9
Figure 9. Figure 9: displays the best fit found with this model. The addi￾tional MYTorusL component can simultaneously fit some of the largest deviations between the best fit of model A and the line pro￾file, at both the high and low energy ends of the line shape. The resulting C-statisti…

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. Full citation record

  1. Physically motivated AGN emissivity profiles and their effects on quasar microlensing signatures. 1. Multi-epoch accretion disc size inference

    astro-ph.GA 2026-07 accept novelty 6.0 of 10

    Interpreting composite disc-plus-BLR emission as a single compact disc systematically overestimates microlensing half-light radii, with the bias set mainly by the BLR flux fraction and the compact-disc emissivity shape.

Reference graph

Works this paper leans on

56 extracted references · 51 canonical work pages · cited by 1 Pith paper

  1. [1]

    Arnaud, K. A. 1996, in Astronomical Society of the Pacific Conference

  2. [2]

    101, Astronomical Data Analysis Software and Systems V , ed

    Series, V ol. 101, Astronomical Data Analysis Software and Systems V , ed. G. H. Jacoby & J. Barnes, 17 Astropy Collaboration, Robitaille, T. P., Tollerud, E. J., et al. 2013, A&A, 558, A33, Astropy Collaboration, Price-Whelan, A. M., Sip ˝ocz, B. M., et al. 2018, AJ, 156, 123, Astropy Collaboration, Price-Whelan, A. M., Lim, P. L., et al. 2022, ApJ, 935, 167,

  3. [3]

    2009, A&A, 505, 417,

    Beckmann, V ., Soldi, S., Ricci, C., et al. 2009, A&A, 505, 417,

  4. [4]

    2002, A&A, 387, 76,

    Bianchi, S., & Matt, G. 2002, A&A, 387, 76,

  5. [5]

    2005, MNRAS, 357, 599,

    Bianchi, S., Matt, G., Nicastro, F., Porquet, D., & Dubau, J. 2005, MNRAS, 357, 599,

  6. [6]

    2009, MNRAS, 394, 660,

    Cappellari, M., Neumayer, N., Reunanen, J., et al. 2009, MNRAS, 394, 660,

  7. [7]

    J., van den Bergh, S., Harvel, C

    Dufour, R. J., van den Bergh, S., Harvel, C. A., et al. 1979, AJ, 84, 284,

  8. [8]

    2009, ApJ, 695, 116,

    Espada, D., Matsushita, S., Peck, A., et al. 2009, ApJ, 695, 116,

Show all 56 references
  1. [9]

    E., et al

    Espada, D., Matsushita, S., Miura, R. E., et al. 2017, ApJ, 843, 136,

  2. [10]

    2016, ApJ, 821, 15,

    Fukazawa, Y ., Furui, S., Hayashi, K., et al. 2016, ApJ, 821, 15,

  3. [11]

    2011, ApJ, 727, 19,

    Fukazawa, Y ., Hiragi, K., Mizuno, M., et al. 2011, ApJ, 727, 19,

  4. [12]

    C., Miller, J

    Gallo, L. C., Miller, J. M., & Costantini, E. 2023, arXiv e-prints, arXiv:2302.10930,

  5. [13]

    G., Wilkins, D

    Gonzalez, A. G., Wilkins, D. R., & Gallo, L. C. 2017, MNRAS, 472, 1932,

  6. [14]

    L., Hardcastle, M

    Goodger, J. L., Hardcastle, M. J., Croston, J. H., et al. 2010, ApJ, 708, 675,

  7. [15]

    Graham, J. A. 1978, PASP, 90, 237,

  8. [16]

    G., et al

    Grandi, P., Fiocchi, M., Perola, C. G., et al. 2003, ApJ, 593, 160,

  9. [17]

    J., Worrall, D

    Hardcastle, M. J., Worrall, D. M., Kraft, R. P., et al. 2003, ApJ, 593, 169,

  10. [18]

    R., Millman, K

    Harris, C. R., Millman, K. J., van der Walt, S. J., et al. 2020, Nature, 585, 357,

  11. [19]

    Harris, G. L. H., Rejkuba, M., & Harris, W. E. 2010, PASA, 27, 457,

  12. [20]

    2011, PASJ, 63, S677, Hölzer, G., Fritsch, M., Deutsch, M., Härtwig, J., & Förster, E

    Hiroi, K., Ueda, Y ., Isobe, N., et al. 2011, PASJ, 63, S677, Hölzer, G., Fritsch, M., Deutsch, M., Härtwig, J., & Förster, E. 1997, Phys. Rev. A, 56, 4554,

  13. [21]

    C., Freeman, K

    Hui, X., Ford, H. C., Freeman, K. C., & Dopita, M. A. 1995, ApJ, 449, 592,

  14. [22]

    Hunter, J. D. 2007, Computing in Science & Engineering, 9, 90,

  15. [23]

    2024, PASJ, 76, 923,

    Iwata, T., Tanimoto, A., Odaka, H., et al. 2024, PASJ, 76, 923,

  16. [24]

    2021, Nature Astronomy, 5, 1017,

    Janssen, M., Falcke, H., Kadler, M., et al. 2021, Nature Astronomy, 5, 1017,

  17. [25]

    L., Tingay, S

    Jones, D. L., Tingay, S. J., Murphy, D. W., et al. 1996, ApJL, 466, L63,

  18. [26]

    E., Schnittman, J

    Kinch, B. E., Schnittman, J. D., Kallman, T. R., & Krolik, J. H. 2016, ApJ, 826, 52,

  19. [27]

    J., Ricci, C., Trakhtenbrot, B., et al

    Koss, M. J., Ricci, C., Trakhtenbrot, B., et al. 2022, ApJS, 261, 2, Krajnovi´c, D., Sharp, R., & Thatte, N. 2007, MNRAS, 374, 385,

  20. [28]

    J., et al

    Marconi, A., Capetti, A., Axon, D. J., et al. 2001, ApJ, 549, 915,

  21. [29]

    Z., et al

    Marin, F., Hutsemékers, D., Jiang, C. Z., et al. 2025, arXiv e-prints, arXiv:2502.05002,

  22. [30]

    S., et al

    McCoy, M., Ott, J., Meier, D. S., et al. 2017, ApJ, 851, 76,

  23. [31]

    2024, arXiv e-prints, arXiv:2406.19911, Müller, C., Kadler, M., Ojha, R., et al

    Mori, K., Tomida, H., Nakajima, H., et al. 2024, arXiv e-prints, arXiv:2406.19911, Müller, C., Kadler, M., Ojha, R., et al. 2014, A&A, 569, A115,

  24. [32]

    D., & Yaqoob, T

    Murphy, K. D., & Yaqoob, T. 2009, MNRAS, 397, 1549,

  25. [33]

    2007, ApJ, 671, 1329,

    Neumayer, N., Cappellari, M., Reunanen, J., et al. 2007, ApJ, 671, 1329,

  26. [34]

    Ogilvie, G. I. 1999, MNRAS, 304, 557,

  27. [35]

    S., Kilbourne, C

    Porter, F. S., Kilbourne, C. A., Chiao, M., et al. 2024, in Society of Photo- Optical Instrumentation Engineers (SPIE) Conference Series, V ol. 13093, Space Telescopes and Instrumentation 2024: Ultraviolet to Gamma Ray, ed. J.-W. A. den Herder, S. Nikzad, & K. Nakazawa, 130931K,

  28. [36]

    J., Bahramian, A., et al

    Prabu, S., Tingay, S. J., Bahramian, A., et al. 2025, AJ, 169, 37,

  29. [37]

    C., Neumayer, N., Oosterloo, T., & Espada, D

    Quillen, A. C., Neumayer, N., Oosterloo, T., & Espada, D. 2010, PASA, 27, 396, Ramos Almeida, C., Levenson, N. A., Rodríguez Espinosa, J. M., et al. 2009, ApJ, 702, 1127,

  30. [38]

    E., Markowitz, A., Rivers, E., et al

    Rothschild, R. E., Markowitz, A., Rivers, E., et al. 2011, ApJ, 733, 23,

  31. [39]

    1978, Annals of Statistics, 6, 461

    Schwarz, G. 1978, Annals of Statistics, 6, 461

  32. [40]

    B., Dermer, C

    Skibo, J. B., Dermer, C. D., & Kinzer, R. L. 1994, ApJL, 426, L23,

  33. [41]

    F., Cutri, R

    Skrutskie, M. F., Cutri, R. M., Stiening, R., et al. 2006, AJ, 131, 1163,

  34. [42]

    W., et al

    Svoboda, J., Dovˇciak, M., Goosmann, R. W., et al. 2012, A&A, 545, A106,

  35. [43]

    2020, in Society of Photo-Optical Instrumentation Engineers (SPIE) Conference Series, V ol

    Tashiro, M., Maejima, H., Toda, K., et al. 2020, in Society of Photo-Optical Instrumentation Engineers (SPIE) Conference Series, V ol. 11444, Space Telescopes and Instrumentation 2020: Ultraviolet to Gamma Ray, ed. J.- W. A. den Herder, S. Nikzad, & K. Nakazawa, 1144422,

  36. [44]

    2024, in Society of Photo- Optical Instrumentation Engineers (SPIE) Conference Series, V ol

    Tashiro, M., Watanabe, S., Maejima, H., et al. 2024, in Society of Photo- Optical Instrumentation Engineers (SPIE) Conference Series, V ol. 13093, Space Telescopes and Instrumentation 2024: Ultraviolet to Gamma Ray, ed. J.-W. A. den Herder, S. Nikzad, & K. Nakazawa, 130931G,

  37. [45]

    J., Jauncey, D

    Tingay, S. J., Jauncey, D. L., Reynolds, J. E., et al. 1998, AJ, 115, 960,

  38. [46]

    Tremaine, S., & Davis, S. W. 2014, MNRAS, 441, 1408,

  39. [47]

    A., Ferland, G

    Verner, D. A., Ferland, G. J., Korista, K. T., & Yakovlev, D. G. 1996, ApJ, 465, 487,

  40. [48]

    E., et al

    Virtanen, P., Gommers, R., Oliphant, T. E., et al. 2020, Nature Methods, 17, 261,

  41. [49]

    R., Rejkuba, M., & Walton, N

    Walsh, J. R., Rejkuba, M., & Walton, N. A. 2015, A&A, 574, A109, Publications of the Astronomical Society of Japan (2025), Vol. 00, No. 0 13

  42. [50]

    R., & Fabian, A

    Wilkins, D. R., & Fabian, A. C. 2012, MNRAS, 424, 1284,

  43. [51]

    Wilkinson, A., Fosbury, R. A. E., Wallace, P. T., & Sharples, R. 1983, in Bulletin of the American Astronomical Society, V ol. 15, 921

  44. [52]

    2000, ApJ, 542, 914,

    Wilms, J., Allen, A., & McCray, R. 2000, ApJ, 542, 914,

  45. [53]

    A., Harris, W

    Woodley, K. A., Harris, W. E., Beasley, M. A., et al. 2007, AJ, 134, 494, XRISM Collaboration, Audard, M., Awaki, H., et al. 2024, ApJL, 973, L25,

  46. [54]

    2012, MNRAS, 423, 3360, —

    Yaqoob, T. 2012, MNRAS, 423, 3360, —. 2024, MNRAS, 527, 1093,

  47. [55]

    2024, MNRAS, 532, 3786,

    Zhang, W., Dovˇciak, M., Bursa, M., Svoboda, J., & Karas, V . 2024, MNRAS, 532, 3786,

  48. [56]

    T., & Czerny, B

    Zycki, P. T., & Czerny, B. 1994, MNRAS, 266, 653, Appendix 1 Investigating a possible additional line component As Figs. 6, 7, and 8 show, there are some further discrepancies between the data and the model at the lowest and highest energies of the broad tails of the Fe K α li...

Pith tools

Reviewed August 6, 2026 · model on record in the stance chip above.