arxiv: 2604.06719 · v1 · submitted 2026-04-08 · 🌌 astro-ph.HE · astro-ph.GA

Recognition: no theorem link

Complex Nuclear Structure in Seyfert 2 Galaxy NGC 4388 Revealed by XRISM Observation

Kanta Fujiwara , Yoshihiro Ueda , Shoji Ogawa , Yuya Nakatani , Jon M. Miller , Takashi Okajima , Taiki Kawamuro , Peter G. Boorman

show 8 more authors

Luigi Gallo Misaki Mizumoto Richard Mushotzky Hirofumi Noda Yuichi Terashima Francesco Tombesi Bert Vander Meulen Satoshi Yamada

Authors on Pith no claims yet

Pith reviewed 2026-05-10 18:09 UTC · model grok-4.3

classification 🌌 astro-ph.HE astro-ph.GA

keywords NGC 4388Seyfert 2Fe K alphaXRISMX-ray reflectionbroad line regiondusty torusAGN absorber

0 comments

The pith

The neutral Fe K fluorescent line in NGC 4388 decomposes into three components tracing emission from the dusty torus, its inner edge, and the broad line region at distinct radii.

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

The paper presents simultaneous XRISM and NuSTAR spectra of the Seyfert 2 galaxy NGC 4388, whose bright neutral iron K-alpha line is modeled with an updated XCLUMPY reflection code plus a disk-like broad line region geometry. The line profile is separated into three Gaussian-broadened components whose widths translate, under a Keplerian assumption, into emission radii of 1.5 pc, 0.06 pc, and 0.001 pc. These scales are interpreted as the torus, its inner edge, and the BLR respectively, while the data also show ionized iron absorption lines from a low-velocity, bound absorber. A reader would care because the result supplies spatially resolved kinematic information on the multi-scale gas structures that surround the central black hole in an obscured active nucleus.

Core claim

The profile of the neutral Fe-K fluorescent line is well described as the sum of three components convolved with Gaussians with FWHM values of ~290 km s^{-1}, ~1470 km s^{-1}, and ~11100 km s^{-1}. These line widths correspond to radii of 1.5 pc, 0.060 pc, and 1.0×10^{-3} pc by assuming Keplerian motion, which we interpret as the dusty torus, its inner edge region, and the BLR, respectively. The data suggest that the Fe Kα BLR component is larger than that of Hα in the polarized optical spectrum, implying that the velocity field of the BLR is dominated by that parallel to the equatorial plane. In addition, Fe XXVI Lyα and Fe XXV absorption lines are detected, characterized by log ξ ~3.50 erg

What carries the argument

Three-component Gaussian decomposition of the neutral Fe Kα line profile within the XCLUMPY reflection model and disk-like BLR geometry, with widths converted to radii via the Keplerian relation.

If this is right

The BLR velocity field traced by Fe Kα is dominated by equatorial motion rather than polar motion.
The detected absorber is gravitationally bound and consistent with a failed wind in a radiation-driven fountain flow.
The inner edge of the dusty torus produces a distinct intermediate-width fluorescent component separate from the main torus and BLR emission.
The nuclear gas structure in this Compton-thin Seyfert 2 is stratified across three orders of magnitude in radius.

Where Pith is reading between the lines

These are editorial extensions of the paper, not claims the author makes directly.

The same three-component decomposition could be tested on other bright obscured AGN with XRISM or future microcalorimeter data to check whether torus-BLR layering is common.
If the Keplerian radii hold, they offer a direct geometric constraint on black-hole mass that can be compared with optical reverberation masses.
The equatorial dominance in the Fe K BLR may help explain why some polarized optical lines appear narrower than their X-ray counterparts in type-2 objects.
Time-resolved XRISM observations could search for variability in the intermediate-width component to test whether the inner torus edge is static or dynamic.

Load-bearing premise

The observed line widths are produced by gas in purely Keplerian orbits around the central black hole.

What would settle it

An independent radius measurement for any of the three Fe K components, for example via reverberation mapping or infrared interferometry, that lies well outside the predicted values of 1.5 pc, 0.06 pc, or 0.001 pc.

Figures

Figures reproduced from arXiv: 2604.06719 by Bert Vander Meulen, Francesco Tombesi, Hirofumi Noda, Jon M. Miller, Kanta Fujiwara, Luigi Gallo, Misaki Mizumoto, Peter G. Boorman, Richard Mushotzky, Satoshi Yamada, Shoji Ogawa, Taiki Kawamuro, Takashi Okajima, Yoshihiro Ueda, Yuichi Terashima, Yuya Nakatani.

**Figure 1.** Figure 1: The light curves obtained with XRISM/Resolve and NuSTAR/FPMs. The NuSTAR light curve (top) is extracted in the 8–70 keV band, while the XRISM/Resolve light curve (bottom) is extracted in the 3–10 keV band. 2.1. XRISM XRISM carries two focal-plane instruments: the Xray microcalorimeter Resolve (Y. Ishisaki et al. 2025; R. L. Kelley et al. 2025)and the X-ray CCD camera Xtend (H. Noda et al. 2025), which ar… view at source ↗

**Figure 2.** Figure 2: Geometry assumed in our reflection modeling. The BLR (left) is treated as a uniform-density wedge with a fixed opening angle, while the torus (right) follows a clumpy structure consistent with the XCLUMPY model. Miller et al. 2025; E. Kammoun et al. 2025) indicate that the Fe Kα emission line likely comprises multiple components, including a narrow line from the torus and a broader component that may arise… view at source ↗

**Figure 3.** Figure 3: XRISM/Resolve spectrum of the Fe K region (black points) with the model (red) and its components. (a) model 1; XCLUMPY only, (b) model 2; XCLUMPY + BLR, (c) model 3; XCLUMPY + XCLUMPY + BLR [PITH_FULL_IMAGE:figures/full_fig_p010_3.png] view at source ↗

**Figure 4.** Figure 4: (continued) (d) model 4; XCLUMPY + XCLUMPY + BLR + pion, (e) model 5; XCLUMPY + XCLUMPY + BLR + pion + pion (final). (rg ≡ GM/c 2 is a gravitational radius where G is the gravitational constant, M is the black hole mass, and c is the speed of light), 1.5 +1.0 −0.7 × 105 rg, and 2.6 +2.3 −1.1 × 103 rg, respectively, for an inclination of 70 degree ( [PITH_FULL_IMAGE:figures/full_fig_p011_4.png] view at source ↗

**Figure 5.** Figure 5: Broad-band (top) and Fe K-band (bottom) spectral fits to the XRISM/Resolve (black) and NuSTAR/FPMA+FPMB (red) data. The total best-fit model is shown in red, and the individual spectral components are plotted separately: the torus-reflection components (blue and purple), the BLR-reflection component (magenta), the absorbed power-law continuum (orange), and the scattered power-law component (green). Promine… view at source ↗

**Figure 6.** Figure 6: Schematic illustration of the circumnuclear environment of NGC 4388 inferred from the joint XRISM/Resolve and NuSTAR/FPMs observations. The central black hole is surrounded by the broad-line region and an obscuring torus, whose geometry and composition are constrained by the spectral decomposition. An ionized absorber detected in the Resolve data exhibits low outflow velocity indicating that the gas is gra… view at source ↗

read the original abstract

We report results from the simultaneous XRISM (183 ks) and NuSTAR (62 ks) observations of the Seyfert-2 galaxy NGC 4388. This AGN has the brightest Fe K$\alpha$ line among Compton-thin, obscured sources. To model the reflection continuum and fluorescent lines, we employ an updated version of XCLUMPY and a broad line region model with a disk-like geometry. The profile of the neutral Fe-K fluorescent line is well described as the sum of three components convolved with Gaussians with FWHM values of $\sim 290\ \mathrm{km\ s^{-1}}$, $\sim 1470\ \mathrm{km\ s^{-1}}$, and $\sim 11100\ \mathrm{km\ s^{-1}}$. These line widths correspond to radii of 1.5 pc, 0.060 pc, and $1.0\times10^{-3}$ pc by assuming Keplerian motion, which we interpret as the dusty torus, its inner edge region, and the BLR, respectively. The data suggest that the Fe K$\alpha$ BLR component is larger than that of H$\alpha$ (FWHM of 4500 $\mathrm{km\ s^{-1}}$) in the polarized optical spectrum, implying that the velocity field of the BLR is dominated by that parallel to the equatorial plane. In addition, Fe XXVI Ly$\alpha$ and Fe XXV absorption lines are detected, characterized by $\log{\xi} \sim 3.50~\mathrm{erg\ cm\ s^{-1}}$, $\log{N_{\mathrm{H}}} \sim 22.1~\mathrm{cm^{-2}}$, $v_{\mathrm{out}} \sim 40\ \mathrm{km\ s^{-1}}$, and $\sigma_v \sim 160\ \mathrm{km\ s^{-1}}$. We infer that the absorber is gravitationally bound and is possibly associated with a failed wind, consistent with a radiation-driven fountain flow.

Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, simulated authors' rebuttal, and a circularity audit. Tearing a paper down is the easy half of reading it; the pith above is the substance, this is the friction.

Desk Editor's Note private letter to a colleague

XRISM data on NGC 4388 cleanly splits the Fe Kα line into three components and gives absorber parameters, but the physical radii rest on an untested Keplerian assumption.

read the letter

The paper's real contribution is the XRISM plus NuSTAR spectrum of this bright Compton-thin Seyfert 2. They decompose the neutral Fe Kα line into three Gaussian components with FWHMs around 290, 1470, and 11100 km/s, then map those to 1.5 pc, 0.06 pc, and 0.001 pc using the updated XCLUMPY reflection model and a disk-like BLR geometry. The absorber comes out with log ξ ~3.5, log NH ~22.1, outflow velocity ~40 km/s, and velocity dispersion ~160 km/s, which they call gravitationally bound and consistent with a failed wind or fountain flow. That is new concrete geometry for this one source and extends earlier lower-resolution work on the same object. The fits themselves look standard and the parameters are internally consistent with the data they show. The main limitation is the radius conversion. It assumes pure Keplerian orbital motion with no turbulence, inflow, or outflow contribution, and the paper does not test alternative velocity fields or quantify how much the radii would shift if the assumption changes. Black-hole mass uncertainty is also not propagated in the abstract or summary. The BLR size comparison to the polarized Hα line is interesting but inherits the same disk-geometry assumption. This is a solid single-object study for people who model the multi-scale gas in nearby obscured AGN or who need updated constraints on torus and BLR structure in unification schemes. It is not broad enough to reorganize the field, but the data quality is high enough that a serious referee should see it. I would send it to review with the request that the authors add a short section testing the Keplerian assumption or showing the effect of reasonable alternatives.

Referee Report

3 major / 2 minor

Summary. The paper reports simultaneous XRISM (183 ks) and NuSTAR (62 ks) observations of the Seyfert-2 galaxy NGC 4388. It models the reflection continuum and fluorescent lines using an updated XCLUMPY model plus a disk-like BLR geometry, decomposes the neutral Fe Kα line into three Gaussian components with FWHMs of ~290, ~1470, and ~11100 km/s, converts these widths to radii of 1.5 pc, 0.060 pc, and 1.0e-3 pc under the Keplerian assumption, and interprets the components as the dusty torus, its inner edge, and the BLR. Absorption lines from Fe XXVI and Fe XXV are fitted with log ξ ~3.50, log N_H ~22.1, v_out ~40 km/s, and σ_v ~160 km/s, leading to the conclusion that the absorber is gravitationally bound and consistent with a failed wind in a radiation-driven fountain flow.

Significance. If the central interpretations hold after validation of the velocity-field assumptions, the result would provide one of the first spatially resolved views of the multi-scale nuclear structure (torus to BLR) in a Compton-thin Seyfert 2 using high-resolution X-ray spectroscopy, strengthening the connection between X-ray and optical BLR properties and offering a concrete test case for radiation-driven fountain models.

major comments (3)

[Abstract] Abstract: The conversion of the three observed FWHMs to physical radii (1.5 pc, 0.060 pc, 1.0×10^{-3} pc) rests on the Keplerian relation r = G M_BH / v^2 with v derived from FWHM; the manuscript provides no quantitative assessment of how non-Keplerian contributions (turbulence, radial flows, or disk inclination effects) would alter these radii, which is load-bearing for the claimed torus-BLR decomposition.
[Abstract] Abstract: The absorber is stated to be gravitationally bound and possibly a failed wind, yet no radial location is derived or assumed against which to compare the measured v_out ~40 km/s to the local escape velocity; this omission prevents a direct test of the bound vs. unbound status central to the fountain-flow interpretation.
[Abstract] Abstract: The claim that the Fe Kα BLR component is larger than the Hα BLR (FWHM 4500 km/s) and therefore implies an equatorial-plane-dominated velocity field depends on the uniqueness of the three-Gaussian decomposition under the specific updated XCLUMPY plus disk-like BLR model; no alternative model comparisons or covariance information are referenced to establish robustness.

minor comments (2)

The abstract and text should include the best-fit χ²/dof, parameter uncertainties, and any covariance between the three Fe Kα components to allow readers to judge the statistical necessity of the three-component model.
Notation for the absorber parameters (log ξ, log N_H, v_out, σ_v) should be defined explicitly on first use and cross-referenced to the fitting section for clarity.

Simulated Author's Rebuttal

3 responses · 0 unresolved

We thank the referee for the constructive and detailed comments. We address each major point below and have revised the manuscript accordingly to strengthen the analysis and clarify assumptions.

read point-by-point responses

Referee: [Abstract] Abstract: The conversion of the three observed FWHMs to physical radii (1.5 pc, 0.060 pc, 1.0×10^{-3} pc) rests on the Keplerian relation r = G M_BH / v^2 with v derived from FWHM; the manuscript provides no quantitative assessment of how non-Keplerian contributions (turbulence, radial flows, or disk inclination effects) would alter these radii, which is load-bearing for the claimed torus-BLR decomposition.

Authors: We agree that the Keplerian assumption is central and that non-Keplerian contributions could affect the precise radii. The distinct scales remain separated by orders of magnitude even allowing for moderate (factor of ~3) uncertainties from turbulence or inclination. In the revised manuscript we add a dedicated paragraph quantifying these effects using simple analytic estimates (e.g., adding isotropic turbulence in quadrature and varying inclination between 30°–60°), while retaining the physical interpretation as torus, inner edge, and BLR. revision: yes
Referee: [Abstract] Abstract: The absorber is stated to be gravitationally bound and possibly a failed wind, yet no radial location is derived or assumed against which to compare the measured v_out ~40 km/s to the local escape velocity; this omission prevents a direct test of the bound vs. unbound status central to the fountain-flow interpretation.

Authors: We acknowledge that an explicit radial location would enable a direct v_out versus v_esc comparison. Using the measured ionization parameter and column density together with the radiation-driven fountain geometry adopted in the paper, we now derive a characteristic radius of ~0.1–0.5 pc for the absorber. At this distance the local escape velocity exceeds 200 km/s, confirming that the observed 40 km/s outflow is gravitationally bound. This calculation and the resulting bound/unbound assessment are added to the revised text. revision: yes
Referee: [Abstract] Abstract: The claim that the Fe Kα BLR component is larger than the Hα BLR (FWHM 4500 km/s) and therefore implies an equatorial-plane-dominated velocity field depends on the uniqueness of the three-Gaussian decomposition under the specific updated XCLUMPY plus disk-like BLR model; no alternative model comparisons or covariance information are referenced to establish robustness.

Authors: The three-component decomposition is required by the data (Δχ² > 30 for two versus three Gaussians) and is physically motivated by the XCLUMPY geometry. To address robustness we now include (i) explicit comparison of two- versus three-component fits with F-test probabilities, (ii) the full covariance matrix for the Gaussian widths, and (iii) a brief exploration of an alternative two-Gaussian plus relativistic disk-line model. These additions confirm that the ~11 000 km/s component remains distinct and larger than the optical Hα BLR. revision: yes

Circularity Check

0 steps flagged

No significant circularity; results are direct fits to new data with explicit assumptions

full rationale

The paper's central results come from spectral fitting of XRISM/NuSTAR data to an updated XCLUMPY reflection model plus a disk-like BLR geometry. Measured FWHMs (~290, 1470, 11100 km/s) are converted to radii via the standard Keplerian formula r = GM_BH / v^2 under an explicitly stated assumption of Keplerian motion; this is an interpretive mapping, not a self-referential definition or fitted input renamed as prediction. Absorber parameters (log ξ, N_H, v_out, σ_v) are likewise direct outputs of the fit. No load-bearing self-citations, uniqueness theorems imported from the same authors, or ansatzes smuggled via prior work are present in the derivation chain. The analysis is self-contained against the observational dataset.

Axiom & Free-Parameter Ledger

4 free parameters · 2 axioms · 1 invented entities

The central claims rest on spectral modeling with multiple free parameters fitted to the line profile and absorption features, plus the domain assumption of Keplerian motion to derive radii and the interpretation of the absorber as a failed wind.

free parameters (4)

FWHM of three Fe Kα components
Fitted values of ~290, ~1470, ~11100 km/s to match the observed line profile
log ξ of absorber
Fitted value ~3.50 to the Fe XXVI and Fe XXV lines
log N_H of absorber
Fitted value ~22.1 cm^{-2}
v_out and σ_v of absorber
Fitted values ~40 km/s and ~160 km/s

axioms (2)

domain assumption Line widths correspond to Keplerian velocities at the quoted radii
Invoked to convert FWHM values into physical radii of 1.5 pc, 0.060 pc, and 1.0×10^{-3} pc
domain assumption XCLUMPY and disk-like BLR models correctly describe the reflection continuum and fluorescent lines
Used to model the data and isolate the three line components

invented entities (1)

failed wind no independent evidence
purpose: To interpret the low-velocity absorption as gravitationally bound gas in a radiation-driven fountain flow
Postulated based on the fitted low v_out and σ_v without independent falsifiable prediction outside the current data

pith-pipeline@v0.9.0 · 5741 in / 1745 out tokens · 66816 ms · 2026-05-10T18:09:08.340219+00:00 · methodology

discussion (0)

Reference graph

Works this paper leans on

77 extracted references · 73 canonical work pages

[1]

A new look at the statistical model identification.IEEE Transactions on Automatic Control19, 716–723 (1974)

Akaike, H. 1974, IEEE Transactions on Automatic Control, 19, 716, doi: 10.1109/TAC.1974.1100705

work page doi:10.1109/tac.1974.1100705 1974
[2]

F., et al

Alonso-Herrero, A., Garc´ ıa-Burillo, S., H¨ onig, S. F., et al. 2021, A&A, 652, A99, doi: 10.1051/0004-6361/202141219

work page doi:10.1051/0004-6361/202141219 2021
[3]

Antonucci, R. R. J., & Miller, J. S. 1985, ApJ, 297, 621, doi: 10.1086/163559 16

work page doi:10.1086/163559 1985
[4]

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

1996
[5]

2019, MNRAS, 489, 2177, doi: 10.1093/mnras/stz2289

Asmus, D. 2019, MNRAS, 489, 2177, doi: 10.1093/mnras/stz2289

work page doi:10.1093/mnras/stz2289 2019
[6]

F., & Gandhi, P

Asmus, D., H¨ onig, S. F., & Gandhi, P. 2016, ApJ, 822, 109, doi: 10.3847/0004-637X/822/2/109

work page doi:10.3847/0004-637x/822/2/109 2016
[7]

2025, PASJ, 77, S209, doi: 10.1093/pasj/psaf084

Bogensberger, D., Nakatani, Y., Yaqoob, T., et al. 2025, PASJ, 77, S209, doi: 10.1093/pasj/psaf084

work page doi:10.1093/pasj/psaf084 2025
[8]

Astrophys

Brenneman, L. W., & Reynolds, C. S. 2006, ApJ, 652, 1028, doi: 10.1086/508146

work page doi:10.1086/508146 2006
[9]

P., & Anderson, D

Burnham, K. P., & Anderson, D. R. 2002, Model Selection and Multimodel Inference: A Practical Information-Theoretic Approach, 2nd edn. (New York: Springer)

2002
[10]

Astronomy and Computing , keywords =

Camps, P., & Baes, M. 2015, Astronomy and Computing, 9, 20, doi: 10.1016/j.ascom.2014.10.004

work page doi:10.1016/j.ascom.2014.10.004 2015
[11]

Astronomy and Computing , keywords =

Camps, P., & Baes, M. 2020, Astronomy and Computing, 31, 100381, doi: 10.1016/j.ascom.2020.100381

work page doi:10.1016/j.ascom.2020.100381 2020
[12]

Cash, Parameter estimation in astronomy through application of the likelihood ratio.ApJ 228, 939–947 (1979), doi:10.1086/156922

Cash, W. 1979, ApJ, 228, 939, doi: 10.1086/156922

work page doi:10.1086/156922 1979
[13]

M., & Kraemer, S

Crenshaw, D. M., & Kraemer, S. B. 2012, ApJ, 753, 75, doi: 10.1088/0004-637X/753/1/75

work page doi:10.1088/0004-637x/753/1/75 2012
[14]

, keywords =

Czerny, B., & Hryniewicz, K. 2011, A&A, 525, L8, doi: 10.1051/0004-6361/201016025

work page doi:10.1051/0004-6361/201016025 2011
[15]

2010, Monthly Notices of the Royal Astronomical Society, 408, 1181, doi: 10.1111/j.1365-2966.2010.17197.x

Dauser, T., Wilms, J., Reynolds, C. S., & Brenneman, L. W. 2010, MNRAS, 409, 1534, doi: 10.1111/j.1365-2966.2010.17393.x

work page doi:10.1111/j.1365-2966.2010.17393.x 2010
[16]

E., Brown, G

Eckart, M. E., Brown, G. V., Chiao, M. P., et al. 2025, Journal of Astronomical Telescopes, Instruments, and Systems, 11

2025
[17]

C., Nandra, K., Reynolds, C

Fabian, A. C., Nandra, K., Reynolds, C. S., et al. 1995, MNRAS, 277, L11, doi: 10.1093/mnras/277.1.L11

work page doi:10.1093/mnras/277.1.l11 1995
[18]

, keywords =

Fabian, A. C., Rees, M. J., Stella, L., & White, N. E. 1989, MNRAS, 238, 729, doi: 10.1093/mnras/238.3.729

work page doi:10.1093/mnras/238.3.729 1989
[19]

2026, ApJ, 997, 352, doi: 10.3847/1538-4357/ae2f61

Uematsu, R. 2026, ApJ, 997, 352, doi: 10.3847/1538-4357/ae2f61

work page doi:10.3847/1538-4357/ae2f61 2026
[20]

2011, ApJ, 727, 19, doi: 10.1088/0004-637X/727/1/19

Fukazawa, Y., Hiragi, K., Mizuno, M., et al. 2011, ApJ, 727, 19, doi: 10.1088/0004-637X/727/1/19

work page doi:10.1088/0004-637x/727/1/19 2011
[21]

F., & Kishimoto, M

Gandhi, P., H¨ onig, S. F., & Kishimoto, M. 2015, ApJ, 812, 113, doi: 10.1088/0004-637X/812/2/113 Garc´ ıa-Burillo, S., Alonso-Herrero, A., Ramos Almeida, C., et al. 2021, A&A, 652, A98, doi: 10.1051/0004-6361/202141075

work page doi:10.1088/0004-637x/812/2/113 2015
[22]

M., Zoghbi, A., et al

Gediman, B., Miller, J. M., Zoghbi, A., et al. 2024, ApJ, 966, 57, doi: 10.3847/1538-4357/ad2fa3

work page doi:10.3847/1538-4357/ad2fa3 2024
[23]

2015, MNRAS, 446, 663, doi: 10.1093/mnras/stu2095 H¨ olzer, G., Fritsch, M., Deutsch, M., H¨ artwig, J., & F¨ orster, E

Hagino, K., Odaka, H., Done, C., et al. 2015, MNRAS, 446, 663, doi: 10.1093/mnras/stu2095 H¨ olzer, G., Fritsch, M., Deutsch, M., H¨ artwig, J., & F¨ orster, E. 1997, PhRvA, 56, 4554, doi: 10.1103/PhysRevA.56.4554

work page doi:10.1093/mnras/stu2095 2015
[24]

P., Wyatt, W

Huchra, J. P., Wyatt, W. F., & Davis, M. 1982, AJ, 87, 1628, doi: 10.1086/113254

work page doi:10.1086/113254 1982
[25]

2022, ApJ, 939, 88, doi: 10.3847/1538-4357/ac97ec

Inaba, K., Ueda, Y., Yamada, S., et al. 2022, ApJ, 939, 88, doi: 10.3847/1538-4357/ac97ec

work page doi:10.3847/1538-4357/ac97ec 2022
[26]

L., Awaki, H., et al

Ishisaki, Y., Kelley, R. L., Awaki, H., et al. 2025, Journal of Astronomical Telescopes, Instruments, and Systems, 11, 042023, doi: 10.1117/1.JATIS.11.4.042023

work page doi:10.1117/1.jatis.11.4.042023 2025
[27]

C., Ueno, S., et al

Iwasawa, K., Fabian, A. C., Ueno, S., et al. 1997, MNRAS, 285, 683, doi: 10.1093/mnras/285.4.683

work page doi:10.1093/mnras/285.4.683 1997
[28]

2018, ApJ, 867, 48, doi: 10.3847/1538-4357/aae20b

Kohno, K. 2018, ApJ, 867, 48, doi: 10.3847/1538-4357/aae20b

work page doi:10.3847/1538-4357/aae20b 2018
[29]

2023, Science, 382, 554, doi: 10.1126/science.adf0569 Jur´ aˇ nov´ a, A., Kara, E., Behar, E., et al

Izumi, T., Wada, K., Imanishi, M., et al. 2023, Science, 382, 554, doi: 10.1126/science.adf0569 Jur´ aˇ nov´ a, A., Kara, E., Behar, E., et al. 2025, arXiv e-prints, arXiv:2512.07950, doi: 10.48550/arXiv.2512.07950

work page doi:10.1126/science.adf0569 2023
[30]

S., Mewe, R., & Nieuwenhuijzen, H

Kaastra, J. S., Mewe, R., & Nieuwenhuijzen, H. 1996, in UV and X-ray Spectroscopy of Astrophysical and Laboratory Plasmas, ed. K. Yamashita & T. Watanabe, 411–414

1996
[31]

2025, ApJL, 994, L13, doi: 10.3847/2041-8213/ae18c2

Kammoun, E., Kawamuro, T., Murakami, K., et al. 2025, ApJL, 994, L13, doi: 10.3847/2041-8213/ae18c2

work page doi:10.3847/2041-8213/ae18c2 2025
[32]

A., Brightman, M., & Balokovi´ c, M

Kamraj, N., Rivers, E., Harrison, F. A., Brightman, M., & Balokovi´ c, M. 2017, ApJ, 843, 89, doi: 10.3847/1538-4357/aa7563

work page doi:10.3847/1538-4357/aa7563 2017
[33]

2010, ApJL, 724, L183, doi: 10.1088/2041-8205/724/2/L183

Kawaguchi, T., & Mori, M. 2010, ApJL, 724, L183, doi: 10.1088/2041-8205/724/2/L183

work page doi:10.1088/2041-8205/724/2/l183 2010
[34]

2016a, ApJS, 225, 14, doi: 10.3847/0067-0049/225/1/14

Terashima, Y. 2016a, ApJS, 225, 14, doi: 10.3847/0067-0049/225/1/14

work page doi:10.3847/0067-0049/225/1/14
[35]

2016b, ApJ, 831, 37, doi: 10.3847/0004-637X/831/1/37

Mushotzky, R. 2016b, ApJ, 831, 37, doi: 10.3847/0004-637X/831/1/37

work page doi:10.3847/0004-637x/831/1/37
[36]

2025, Journal of Astronomical Telescopes, Instruments, and Systems, 11, 042026, doi: 10.1117/1.JATIS.11.4.042026

Kelley, R. L., Ishisaki, Y., Costantini, E., et al. 2025, Journal of Astronomical Telescopes, Instruments, and Systems, 11, 042026, doi: 10.1117/1.JATIS.11.4.042026

work page doi:10.1117/1.jatis.11.4.042026 2025
[37]

F., Beckert, T., & Weigelt, G

Kishimoto, M., H¨ onig, S. F., Beckert, T., & Weigelt, G. 2007, A&A, 476, 713, doi: 10.1051/0004-6361:20077911

work page doi:10.1051/0004-6361:20077911 2007
[38]

2023, ApJ, 950, 72, doi: 10.3847/1538-4357/accc2b

Kudoh, Y., Wada, K., Kawakatu, N., & Nomura, M. 2023, ApJ, 950, 72, doi: 10.3847/1538-4357/accc2b

work page doi:10.3847/1538-4357/accc2b 2023
[39]

Y., Braatz, J

Kuo, C. Y., Braatz, J. A., Condon, J. J., et al. 2011, ApJ, 727, 20, doi: 10.1088/0004-637X/727/1/20

work page doi:10.1088/0004-637x/727/1/20 2011
[40]

S., Gu, L., et al

Li, C., Kaastra, J. S., Gu, L., et al. 2026, A&A, 706, A255, doi: 10.1051/0004-6361/202557710

work page doi:10.1051/0004-6361/202557710 2026
[41]

F., Ricci, C., & Paltani, S

Liu, J., H¨ onig, S. F., Ricci, C., & Paltani, S. 2019, MNRAS, 490, 4344, doi: 10.1093/mnras/stz2908 17

work page doi:10.1093/mnras/stz2908 2019
[42]

Lodders, K., Palme, H., & Gail, H. P. 2009, Landolt B¨ ornstein, 4B, 712, doi: 10.1007/978-3-540-88055-434

work page doi:10.1007/978-3-540-88055-434 2009
[43]

2010, A&A, 512, A34, doi: 10.1051/0004-6361/200913298

Lusso, E., Comastri, A., Vignali, C., et al. 2010, A&A, 512, A34, doi: 10.1051/0004-6361/200913298

work page doi:10.1051/0004-6361/200913298 2010
[44]

2022, MNRAS, 512, 2961, doi: 10.1093/mnras/stab3178

McKaig, J., Ricci, C., Paltani, S., & Satyapal, S. 2022, MNRAS, 512, 2961, doi: 10.1093/mnras/stab3178

work page doi:10.1093/mnras/stab3178 2022
[45]

McKernan, B., Yaqoob, T., & Reynolds, C. S. 2007, MNRAS, 379, 1359, doi: 10.1111/j.1365-2966.2007.11993.x

work page doi:10.1111/j.1365-2966.2007.11993.x 2007
[46]

S., & Kallman, T

Mehdipour, M., Kaastra, J. S., & Kallman, T. 2016, A&A, 596, A65, doi: 10.1051/0004-6361/201628721

work page doi:10.1051/0004-6361/201628721 2016
[47]

S., Kriss, G

Mehdipour, M., Kaastra, J. S., Kriss, G. A., et al. 2015, A&A, 575, A22, doi: 10.1051/0004-6361/201425373

work page doi:10.1051/0004-6361/201425373 2015
[48]

S., Eckart, M

Mehdipour, M., Kaastra, J. S., Eckart, M. E., et al. 2025, A&A, 699, A228, doi: 10.1051/0004-6361/202555623 Mej´ ıa-Restrepo, J. E., Trakhtenbrot, B., Koss, M. J., et al. 2022, ApJS, 261, 5, doi: 10.3847/1538-4365/ac6602

work page doi:10.1051/0004-6361/202555623 2025
[49]

M., Kammoun, E., Ludlam, R

Miller, J. M., Kammoun, E., Ludlam, R. M., et al. 2019, ApJ, 884, 106, doi: 10.3847/1538-4357/ab3e05

work page doi:10.3847/1538-4357/ab3e05 2019
[50]

M., Kaastra, J

Miller, J. M., Kaastra, J. S., Miller, M. C., et al. 2015, Nature, 526, 542, doi: 10.1038/nature15708

work page doi:10.1038/nature15708 2015
[51]

M., Xiang, X., Byun, D., et al

Miller, J. M., Xiang, X., Byun, D., et al. 2025, ApJL, 994, L10, doi: 10.3847/2041-8213/ae1606

work page doi:10.3847/2041-8213/ae1606 2025
[52]

2015, ApJ, 802, 98, doi: 10.1088/0004-637X/802/2/98

Minezaki, T., & Matsushita, K. 2015, ApJ, 802, 98, doi: 10.1088/0004-637X/802/2/98

work page doi:10.1088/0004-637x/802/2/98 2015
[53]

2024, MNRAS, 532, 666, doi: 10.1093/mnras/stae1482

Mizukoshi, S., Minezaki, T., Sameshima, H., et al. 2024, MNRAS, 532, 666, doi: 10.1093/mnras/stae1482

work page doi:10.1093/mnras/stae1482 2024
[54]

2021, MNRAS, 503, 1442, doi: 10.1093/mnras/staa3282

Odaka, H. 2021, MNRAS, 503, 1442, doi: 10.1093/mnras/staa3282

work page doi:10.1093/mnras/staa3282 2021
[55]

2023, MNRAS, 523, 6239, doi: 10.1093/mnras/stad1836

Nakatani, Y., Ueda, Y., Ricci, C., et al. 2023, MNRAS, 523, 6239, doi: 10.1093/mnras/stad1836

work page doi:10.1093/mnras/stad1836 2023
[56]

M., Ivezi´ c,ˇZ., & Elitzur, M

Nenkova, M., Sirocky, M. M., Ivezi´ c,ˇZ., & Elitzur, M. 2008a, ApJ, 685, 147, doi: 10.1086/590482

work page doi:10.1086/590482
[57]

2008b, ApJ, 685, 160, doi: 10.1086/590483

Elitzur, M. 2008b, ApJ, 685, 160, doi: 10.1086/590483

work page doi:10.1086/590483
[58]

2025, PASJ, 77, S10, doi: 10.1093/pasj/psaf011

Noda, H., Mori, K., Tomida, H., et al. 2025, PASJ, 77, S10, doi: 10.1093/pasj/psaf011

work page doi:10.1093/pasj/psaf011 2025
[59]

2016, MNRAS, 462, 2366, doi: 10.1093/mnras/stw1764

Odaka, H., Yoneda, H., Takahashi, T., & Fabian, A. 2016, MNRAS, 462, 2366, doi: 10.1093/mnras/stw1764

work page doi:10.1093/mnras/stw1764 2016
[60]

2021, ApJ, 906, 84, doi: 10.3847/1538-4357/abccce

Ogawa, S., Ueda, Y., Tanimoto, A., & Yamada, S. 2021, ApJ, 906, 84, doi: 10.3847/1538-4357/abccce

work page doi:10.3847/1538-4357/abccce 2021
[61]

2022, ApJ, 925, 55, doi: 10.3847/1538-4357/ac3cb9 Ramos Almeida, C., Mart´ ınez Gonz´ alez, M

Ogawa, S., Ueda, Y., Wada, K., & Mizumoto, M. 2022, ApJ, 925, 55, doi: 10.3847/1538-4357/ac3cb9 Ramos Almeida, C., Mart´ ınez Gonz´ alez, M. J., Asensio

work page doi:10.3847/1538-4357/ac3cb9 2022
[62]

2016, MNRAS, 461, 1387, doi: 10.1093/mnras/stw1388 Ramos Almeida, C., & Ricci, C

Ramos, A., et al. 2016, MNRAS, 461, 1387, doi: 10.1093/mnras/stw1388 Ramos Almeida, C., & Ricci, C. 2017, Nature Astronomy, 1, 679, doi: 10.1038/s41550-017-0232-z

work page doi:10.1093/mnras/stw1388 2016
[63]

BAT AGN Spectroscopic Survey - V. X-ray properties of the Swift/BAT 70-month AGN catalog

Ricci, C., Trakhtenbrot, B., Koss, M. J., et al. 2017, ApJS, 233, 17, doi: 10.3847/1538-4365/aa96ad

work page Pith review doi:10.3847/1538-4365/aa96ad 2017
[64]

2018, ApJ, 853, 146, doi: 10.3847/1538-4357/aaa47c

Tanimoto, A., Ueda, Y., Kawamuro, T., et al. 2018, ApJ, 853, 146, doi: 10.3847/1538-4357/aaa47c

work page doi:10.3847/1538-4357/aaa47c 2018
[65]

2019, The Astrophysical Journal, 877, 95, doi: 10.3847/1538-4357/ab1b20

Tanimoto, A., Ueda, Y., Odaka, H., et al. 2019, ApJ, 877, 95, doi: 10.3847/1538-4357/ab1b20

work page doi:10.3847/1538-4357/ab1b20 2019
[66]

2020, ApJ, 897, 2, doi: 10.3847/1538-4357/ab96bc

Tanimoto, A., Ueda, Y., Odaka, H., et al. 2020, ApJ, 897, 2, doi: 10.3847/1538-4357/ab96bc

work page doi:10.3847/1538-4357/ab96bc 2020
[67]

2021, in Society of Photo-Optical Instrumentation Engineers (SPIE) Conference Series, Vol

Tashiro, M., Maejima, H., Toda, K., et al. 2021, in Society of Photo-Optical Instrumentation Engineers (SPIE) Conference Series, Vol. 11444, Society of Photo-Optical Instrumentation Engineers (SPIE) Conference Series, ed. J.-W. A. den Herder, S. Nikzad, & K. Nakazawa, 1144422, doi: 10.1117/12.2565812

work page doi:10.1117/12.2565812 2021
[68]

2025, PASJ, 77, S1, doi: 10.1093/pasj/psaf023

Tashiro, M., Kelley, R., Watanabe, S., et al. 2025, PASJ, doi: 10.1093/pasj/psaf023

work page doi:10.1093/pasj/psaf023 2025
[69]

N., et al

Tombesi, F., Cappi, M., Reeves, J. N., et al. 2013, MNRAS, 430, 1102, doi: 10.1093/mnras/sts692

work page doi:10.1093/mnras/sts692 2013
[70]

Watson, M. G. 2014, ApJ, 786, 104, doi: 10.1088/0004-637X/786/2/104

work page doi:10.1088/0004-637x/786/2/104 2014
[71]

2021, ApJ, 913, 17, doi: 10.3847/1538-4357/abf0a2 Vander Meulen, B., Camps, P., Stalevski, M., & Baes, M

Uematsu, R., Ueda, Y., Tanimoto, A., et al. 2021, ApJ, 913, 17, doi: 10.3847/1538-4357/abf0a2 Vander Meulen, B., Camps, P., Stalevski, M., & Baes, M. 2023, A&A, 674, A123, doi: 10.1051/0004-6361/202245783 Vander Meulen, B., Camps, P., Tsujimoto, M., & Wada, K. 2024, A&A, 688, L33, doi: 10.1051/0004-6361/202451370

work page doi:10.3847/1538-4357/abf0a2 2021
[72]

and Wilkinson, M

Vasudevan, R. V., & Fabian, A. C. 2009, MNRAS, 392, 1124, doi: 10.1111/j.1365-2966.2008.14108.x

work page doi:10.1111/j.1365-2966.2008.14108.x 2009
[73]

doi:10.1088/0004-637X/758/1/66

Wada, K. 2012, ApJ, 758, 66, doi: 10.1088/0004-637X/758/1/66

work page doi:10.1088/0004-637x/758/1/66 2012
[74]

doi:10.3847/2041-8205/828/2/L19

Wada, K., Schartmann, M., & Meijerink, R. 2016, ApJL, 828, L19, doi: 10.3847/2041-8205/828/2/L19

work page doi:10.3847/2041-8205/828/2/l19 2016
[75]

Willingale, R., Starling, R. L. C., Beardmore, A. P., Tanvir, N. R., & O’Brien, P. T. 2013, MNRAS, 431, 394, doi: 10.1093/mnras/stt175

work page doi:10.1093/mnras/stt175 2013
[76]

M., Behar, E., et al

Xiang, X., Miller, J. M., Behar, E., et al. 2025, ApJL, 988, L54, doi: 10.3847/2041-8213/adee9b XRISM collaboration. 2026, arXiv e-prints, arXiv:2603.29748, doi: 10.48550/arXiv.2603.29748 XRISM Collaboration, Audard, M., Awaki, H., et al. 2024, ApJL, 973, L25, doi: 10.3847/2041-8213/ad7397

work page doi:10.3847/2041-8213/adee9b 2025
[77]

2023, MNRAS, 522, 394, doi: 10.1093/mnras/stad782

Yaqoob, T., Tzanavaris, P., & LaMassa, S. 2023, MNRAS, 522, 394, doi: 10.1093/mnras/stad782

work page doi:10.1093/mnras/stad782 2023