Pith. sign in

REVIEW 4 major objections 6 minor 70 references

NICER Spectral and Timing Analysis of 4U 1630$-$47 and its Heartbeat State

T0 review · 4 major / 6 minor · reviewed 2026-08-11 · deepseek-v4-flash

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

Pith's one-line read 4U 1630–47's heartbeat is driven by an inner-disk radiation-pressure instability, with phase-resolved flux tracking disk parameters and a one-second hard lag near the heartbeat frequency.

desk verdict Solid empirical paper with a new heartbeat detection and careful wind/reflection analysis; the disk-instability interpretation is plausible but not yet secured by the phase-resolved statistics, and a factor-10 frequency error needs fixing. read the letter →

arxiv 2412.07621 v2 pith:DUADPTPB submitted 2024-12-10 astro-ph.HE

Ningyue Fan , James F. Steiner , Cosimo Bambi , Erin Kara , Yuexin Zhang , Ole König This is my paper · ORCID
classification astro-ph.HE
keywords blackholeX-raybinaries4U1630-47heartbeatstatephase-resolvedspectroscopyradiationpressureinstabilitytimingaccretiondiskcoronarelativisticreflection
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

The paper analyzes six years of NICER observations of the black hole X-ray binary 4U 1630–47, centering on two observations (September 2021 and March 2023) where the source entered its heartbeat state and the light curve oscillated quasi-periodically at about 5 mHz. By folding the heartbeat and fitting the spectrum in each phase bin, the paper claims that flux tracks the inner disk properties — temperature, inner radius, and mass accretion rate — while the coronal parameters show no strong correlation with flux, exactly the pattern expected if the oscillation is driven by the inner-disk radiation-pressure instability. Supporting timing evidence is a ~1 s hard lag between 4–12 keV and 2–3 keV photons near the heartbeat frequency, with high coherence, attributed to viscous propagation of accretion fluctuations through the disk. If these claims hold, the heartbeat is a disk-originated oscillation that the corona later up-scatters, and the disk itself stays stable and untruncated through the intermediate states.

What carries the argument

The load-bearing machinery is phase-resolved spectral fitting under a disk-plus-corona decomposition. Each ~2 s phase bin of the folded ~18–20 s heartbeat is fit with the model tbfeo × thcomp ⊗ diskbb, and in a cross-check with tbfeo × thcomp ⊗ kerrd, after which the Pearson correlation of the folded count rate with each spectral parameter is evaluated; this is what allows the paper to attribute the flux oscillation to the disk rather than the corona. The timing side is carried by Fourier analysis: energy-resolved power spectra modeled with Lorentzians to measure fractional rms, and lag and coherence spectra computed against a 2–3 keV reference band to find the ~1 s hard lag. The interpretive thread is the radiation-pressure-instability S-curve of the accretion disk, which connects the observed fast swings in disk parameters to the viscous timescale associated with the changing inner disk radius.

What would settle it

Take a future heartbeat observation of 4U 1630–47 with more cycles and higher count rate, phase-resolve with twice as many bins, and let both disk and coronal normalizations vary independently: if the disk–flux correlations weaken or the coronal parameters track flux at ≳3σ, the radiation-pressure-instability reading loses its main spectral support, and if the ~1 s hard lag is absent at the heartbeat frequency in a longer observation, the viscous-propagation interpretation is falsified.

Watch

Extended reading notes

Core claim

On the paper's own terms, the central discovery is that the heartbeat of 4U 1630–47 behaves like an inner-disk radiation-pressure instability: in both heartbeat observations, higher flux comes with higher inner-disk temperature, smaller inner radius (lower diskbb normalization, and in the kerrd cross-check a smaller $R_{\rm in}$ and higher $\dot M$), while the coronal photon index and covering fraction show no strong correlation with flux. The paper also finds a hard lag of roughly one second near the heartbeat frequency with coherence above about 0.8, and a fractional rms that grows with photon energy. Its interpretation combines these: the inner disk produces the oscillation, the fluctuation propagates outward on a viscous timescale, and Compton scattering by the corona magnifies it at higher energies, so the rms–energy trend does not require the corona itself to be the origin of the heartbeat. A supporting result from the same dataset is that relativistic reflection fits of nine intermediate-state spectra from the 2021 outburst give a stable inner radius near the innermost stable circular orbit, arguing against a truncated disk in those states.

Load-bearing premise

The heartbeat interpretation assumes the phase-binned spectral fits genuinely separate the disk and the corona, so the swings in disk temperature and radius are physical and the flat coronal parameters are not just a sensitivity limit of nine or ten phase bins.

Editorial extensions

If this is right

  • If the heartbeat is an inner-disk radiation-pressure instability, then the two heartbeats observed in 2021 and 2023 can share one mechanism even though their time-averaged spectra and inner-disk temperatures differ markedly.
  • The positive rms–energy trend in the heartbeat does not require a coronal origin; a disk-seeded oscillation that the corona Compton-scatters can explain it, consistent with the flat phase-resolved coronal parameters.
  • The stable inner radius found in the intermediate states, if correct, weighs against truncated-disk models for 4U 1630–47 during the HIMS-to-SIMS transition.
  • The ~1 s hard lag near the heartbeat frequency with high coherence implies that the seed and scattered photons are causally linked on a viscous timescale, not a light-travel (reverberation) timescale.

Reading between the lines

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

  • The paper does not test this, but a higher-statistics heartbeat observation with more cycles and finer phase bins should either recover the same disk–flux correlation or reveal that the flat coronal parameters were a sensitivity limit; the latter would weaken the central claim.
  • One could measure the hard lag as a function of heartbeat phase across many cycles: if it is viscous propagation, its magnitude should track the changing inner disk radius over the cycle, a measurement the paper does not attempt.
  • The absence of wind absorption during the heartbeats, despite the wind's recurrence in other outbursts, suggests the wind and heartbeat are independent phenomena tied to different disk temperatures; future simultaneous wind-plus-heartbeat detections in this source would complicate that picture.
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

4 major / 6 minor

Summary. This paper presents a spectral and timing analysis of 251 NICER observations of the black hole X-ray binary 4U 1630–47 from 2018 to 2024. The authors fit the 2–10 keV spectra with an absorbed disk-blackbody plus Comptonization model, identify relativistic reflection features in nine spectra and disk wind absorption features in many spectra, and model them with relxillCp and XSTAR, respectively. They report two heartbeat-state observations, in 2021 and 2023, and perform phase-resolved spectral fitting with diskbb and kerrd, finding correlations between count rate and disk parameters but not coronal parameters. They also report a ~1 s hard lag and high coherence near the heartbeat frequency. On this basis they argue that the heartbeat is driven by an inner-disk radiation-pressure instability, with variability propagating through the disk and being Compton-scattered by the corona.

Significance. If the central interpretation is correct, this is a valuable empirical contribution to the debate on heartbeat mechanisms in black hole X-ray binaries. The paper has several strengths: it uses standard, reproducible NICER reduction and spectral-fitting tools; it provides a quantitative criterion for wind detection; it reports two independent heartbeat epochs with concordant behavior; and it cross-checks the phase-resolved result with two different thermal disk models (diskbb and kerrd). The timing analysis (lag and coherence) adds an independent constraint. However, as discussed below, the phase-resolved correlation analysis currently has limited statistical power to separate disk-driven from coronal-driven variability, and a model-degeneracy check is required before the radiation-pressure-instability conclusion is secure. The manuscript is therefore promising but needs revision.

major comments (4)
  1. [§4.1–4.2, Figs. 14–15] The central claim that the heartbeat is a disk-driven oscillation rests on the phase-resolved correlation analysis, but the statistical support is weaker than the narrative suggests. With only 9–10 phase bins, Pearson coefficients such as 0.47±0.25 (2021, Tin) and −0.64±0.15 (2023, diskbb norm) have large uncertainties, and the statement that coronal parameters show "no strong correlation" is a null result whose statistical power is not quantified. Please report the coronal correlation coefficients with uncertainties, a power estimate for detecting a coronal correlation of the same amplitude as the disk correlations, and an error-including correlation test (bootstrap or MCMC) for the disk parameters.
  2. [§4.1–4.2] The phase-resolved fits use tbfeo×thcomp⊗diskbb over 2–10 keV, where the seed disk temperature/normalization and the Comptonizing corona parameters are degenerate. The anti-correlated Tin/diskbb-norm changes and the kerrd Rin/Mdot swings could be produced by the model trading a flux-driven spectral shape change between the disk and corona components. To secure the interpretation, demonstrate that the phase-resolved correlations survive when coronal parameters are fixed at phase-averaged values, when parameter covariances are included in the correlation test, and/or when an alternative continuum model is used.
  3. [§5.2, Fig. 17] The ~1 s hard lag near the heartbeat frequency is reported from a narrow frequency range around 5 mHz, where the number of independent frequency bins is small. Please quantify the uncertainty on the lag estimates and the detection significance, and state how many independent bins fall in the yellow region. Without this, the lag could be a chance fluctuation at one of several frequency bins, and the claim that the lag is physically meaningful is not secured.
  4. [§3.3, Fig. 11] The stable and untruncated disk conclusion from relxillCp depends on fixing a*=0.998, inclination=64°, and kTe=50 keV. The paper mentions the spin/inner-radius degeneracy but does not quantify how Rin changes under plausible variations of the fixed parameters, nor how the phase-resolved Rin swings in Fig. 15 depend on the assumed mass and distance. A robustness test of these fixed assumptions would strengthen this secondary claim, which is highlighted in the abstract.
minor comments (6)
  1. [Conclusions] The text says the light curves oscillate "at a frequency around 0.05 Hz"; this should read "around 0.005 Hz" (or 5 mHz), consistent with the values quoted in §2.
  2. [Fig. 8] The model label in the top panel uses "tbfeo×thcomp×diskbb" with a multiplication sign, whereas the text uses "⊗" for the convolution; make this notation consistent.
  3. [Fig. 1] The x-axis label contains an unexplained "+5.85e4"; this offset should be removed or described in the caption.
  4. [Appendix A] The wind-detection criterion uses the 90% upper bound crossing zero; also report best-fit equivalent widths and uncertainties for the representative spectra so the reader can see how close the detections are to the threshold.
  5. [Figs. 14–15] Please ensure that the 90% parameter uncertainties are shown on each phase bin, since the significance of the phase trends is hard to assess otherwise.
  6. [§3.2] Because the XSTAR grid uses the averaged best-fit continuum as the seed, a brief statement on the sensitivity of the derived wind parameters to this choice would be useful.

Circularity Check

0 steps flagged · score 0.0 of 10

No significant circularity: results are empirical fits with standard external models; interpretations invoke external theory.

full rationale

The paper's central claims are empirical fits to NICER data using standard external spectral models (tbfeo, thcomp, diskbb, relxillCp, XSTAR, kerrd) and standard timing tools (stingray, Pearson correlations, Lorentzian PDS fits). The phase-resolved heartbeat result—count rate correlated with disk temperature, normalization, inner radius, and mass accretion rate but not coronal parameters—is a reported property of the fitted parameters, not a quantity forced by the model definitions. The thcomp and diskbb degeneracies could complicate interpretation, but they do not make the correlation an identity. The statement that the result is 'consistent with the scenario given by the inner disk radiation pressure instability' is an external theoretical comparison, not a derivation from the paper's inputs. The relxillCp untruncated-disk conclusion follows from fitting the inner radius with the spin fixed at 0.998; fixing a parameter is a stated assumption, not a circular reduction, and the fitted inner-radius values are not preset. Self-citations, such as König et al. (2025, in preparation) and Fan et al. (2024), are not load-bearing: removing them would not change the fitted results or the main argument. No fitted parameter is renamed as a prediction, and no invoked theorem is author-specific or uniqueness-based. Therefore no significant circularity is present.

Assumptions & free parameters 5 free parameters · 6 assumptions · 0 invented entities

This is a pure data-analysis paper using established external models and public data; no new entities are introduced. The listed free parameters are the fixed or jointly fitted values on which the conclusions depend. The per-spectrum fitted quantities (Tin, diskbb norm, photon index, wind NH, log xi, and redshift) are treated as measurements from standard models rather than hidden degrees of freedom; they are the outputs the paper reports, not inputs tuned to force a result.

free parameters (5)
  • Black hole spin a* = 0.998 (fixed)
    Fixed at the maximum in relxillCp to break the spin-inner-radius degeneracy (Sec. 3.3); the 'untruncated disk' conclusion is contingent on this value.
  • Disk inclination = 64 degrees (fixed)
    Adopted from King et al. (2014) in the relxillCp fits (Sec. 3.3); affects Rin and normalization.
  • Corona temperature kTe = 50 keV (fixed)
    Fixed because data below 10 keV cannot constrain it (Sec. 3.3); the authors note 100 keV changes only the photon index scale.
  • tbfeo column and abundances = NH = 16.96e22 cm^-2, [O] = 0.21, [Fe] = 0.69
    Jointly fitted to nine selected spectra (Sec. 3.1) and then fixed for all other fits; all subsequent spectral results inherit these values.
  • Black hole mass and distance in kerrd fits = 10 Msun, 10 kpc (assumed)
    Assumed in Sec. 4.2 for kerrd Rin and Mdot; the authors caution that distance and mass are poorly constrained for this source, so absolute values are uncertain, though the correlation trends are unaffected.
assumptions (6)
  • domain assumption The relxillCp reflection model, with spin 0.998 and inclination 64 degrees, correctly describes the disk reflection spectrum and maps Rin to ISCO units.
    Invoked in Sec. 3.3; the stable untruncated disk conclusion follows from this model choice.
  • domain assumption A single XSTAR grid computed from an averaged best-fit continuum describes the wind absorption in all wind spectra.
    Sec. 3.2: 'almost all spectra can be fit well with the XSTAR table model with the same seed spectrum.'
  • domain assumption State boundaries (hard, HIMS, SIMS, soft) calibrated on other sources apply to 4U 1630-47 in the hardness-rms diagram.
    Sec. 2 and Fig. 3; the source's HID does not follow a standard Q-track, so HRD boundaries from Plant et al. (2014) and similar works are used.
  • domain assumption The temperature-dependent color correction fcol proportional to T^1/4 applies, so the constant-Rin contours in Fig. 12 are valid.
    Sec. 6.1, citing Kubota and Makishima (2004) and Davis et al. (2006); the claim that Rin is constant in the soft state relies on this scaling.
  • domain assumption The heartbeat is a stable periodic template for phase folding, with cycle starts at maximum count rate.
    Sec. 4, following Neilsen et al. (2011); each phase bin averages about 10 to 16 cycles under this assumption.
  • domain assumption The 3C50 model correctly estimates the NICER background in the 2-10 keV band.
    Sec. 2; standard NICER practice, affecting all spectra.

how reviews work

0 comments
Cite this review

Pith. "Pith review of NICER Spectral and Timing Analysis of 4U 1630$-$47 and its Heartbeat State." pith.science (2026). https://pith.science/paper/DUADPTPB

@misc{pith2026241207621,
  author       = {Pith},
  title        = {Pith review of: NICER Spectral and Timing Analysis of 4U 1630$-$47 and its Heartbeat State},
  year         = {2026},
  howpublished = {\url{https://pith.science/paper/DUADPTPB}},
  note         = {Machine review of arXiv:2412.07621}
}
read the original abstract

We present a spectral and timing analysis of NICER observations of the black hole X-ray binary 4U 1630-47 from 2018 to 2024. We find relativistic reflection features in the hard and soft intermediate states, and disk wind absorption features in the soft intermediate state and soft state. We fit the reflection features with relxillCP and find a stable and untruncated disk in the intermediate states; we fit the wind features with XSTAR and find a stable, highly ionized wind with high column density across different outbursts. Specifically, the heartbeat state is seen in two observations in 2021 and 2023 respectively. Through the phase-resolved spectral fitting, we find the flux of the source to be correlated with the disk parameters while no strong correlation with the coronal parameters is observed, consistent with the scenario given by the inner disk radiation pressure instability. A hard lag on the time scale of 1 s and high coherence is observed near the characteristic frequency of the heartbeat, which can be explained by the viscous propagation of mass accretion fluctuations in the disk. The positive relationship between the heartbeat fractional rms and energy can possibly be explained by a disk-originated oscillation which is then magnified by the corona scattering.

Figures

Figures reproduced from arXiv: 2412.07621 by the authors.

Figure 1
Figure 1. Light curve of the NICER observations of 4U 1630–47 from 2018 to 2024. Observations are colored by calendar year. The two stars mark the observations where the heartbeat is seen. Triangles mark the observations used to constrain the elemental abundances with tbfeo in Section 3. 0.25 0.50 0.75 1.00 1.25 1.50 1.75 Hardness ratio (5-10 keV/2-5 keV) 10 0 10 1 10 2 10 3 Intensity (cts/s, 2-10 keV) reflection disk wind HB… view at source ↗
Figure 2
Figure 2. The HID of the NICER observations of 4U 1630– 47 from 2018 to 2024. The hardness is defined as the ratio between the count rates in the 5–10 keV band and the 2– 5 keV band. Observations are color-coded as in [PITH_FULL_IMAGE:figures/full_fig_p003_2.png] view at source ↗
Figure 4
Figure 4. The PDS of the two observations when the heart￾beat is observed. Observation ID 4130010115 corresponds to the observation on September 27, 2021 (MJD 59485), while Observation ID 6130010109 corresponds to the observation on March 27, 2023 (MJD 60031). For the 2021 heartbeat, the PDS peaks at 5.6 +0.4 −0.6 mHz. For the 2023 heartbeat, the PDS peaks at 4.7 +0.4 −0.4 mHz. soft state. However, in 2021, we detect a clear … view at source ↗
Figures from the paper (13 more)
Figure 6
Figure 6. Figure 6: Fits and their residuals for the selected spec￾tra shown with green triangles in [PITH_FULL_IMAGE:figures/full_fig_p005_6.png]
Figure 7
Figure 7. Figure 7: The reduced χ 2 of the fits with the model tbfeo × thcomp ⊗ diskbb. The purple crosses mark the spectra with clear disk wind absorption features. The green diamonds mark the spectra with reflection features. 3 × 10 0 4 × 10 0 6 × 10 0 10 4 10 2 10 0 10 2 k e V 2 (p h s…
Figure 8
Figure 8. Figure 8: A typical and representative spectrum with disk wind features, taken from Observation ID 5130010101 ob￾tained on July 30, 2022 (MJD 59786). The top panel shows the fits with (blue) and without (red) having included a wind component. The two magenta dashed vertical line…
Figure 10
Figure 10. Figure 10: Fitting results of the parameters in the model tbfeo × xstar × thcomp ⊗ diskbb. The parameters are (from top to bottom): the red shift, the column density, and the ionization degree of the wind. fixed at 64◦ (King et al. 2014). The reflection frac￾tion is set to −1 so…
Figure 12
Figure 12. Figure 12: The fitting results showing the relationship be￾tween the inner-disk temperature and the disk normalization. The two arrows show the changing trend of hardness. The dashed line show constant Rin contours, calculated from the equation normdiskbb = (Rin/(f 2 colD10))2 c…
Figure 11
Figure 11. Figure 11: Fitting results of the parameters in the model tbfeo × thcomp ⊗ (diskbb + relxillCp). The parame￾ters are (from top to bottom): the photon index Γ, the cov￾ering fraction of the corona over the disk, the inner disk tem￾perature, the normalization factor of the disk co…
Figure 13
Figure 13. Figure 13: The phase-folded light curves for the 2021 heartbeat state (left) and 2023 heartbeat state (right). Gray points show the phase-mapped individual oscillations. The blue line shows the averaged folded light curve. 1.2 1.4 1.6 1.8 Tin (k e V) 2021 heartbeat Correlation: …
Figure 14
Figure 14. Figure 14: The changes of disk parameters with phase in one heartbeat oscillation, fitted using the model tbfeo × thcomp ⊗ diskbb for the 2021 heartbeat state (left) and 2023 heartbeat state (right).The phase-folded lightcurve is overlaid in gray as a reference. The inner disk t…
Figure 15
Figure 15. Figure 15: As in [PITH_FULL_IMAGE:figures/full_fig_p011_15.png]
Figure 16
Figure 16. Figure 16: The energy dependence of the PDS properties of the heartbeat states in 2021 (left) and 2023 (right). Top panel: the energy-resolved PDS for 2–3 keV, 3–4 keV,4–7 keV and 7–12 keV. Lower panel: the energy dependence of the fractional rms in the heartbeat state. (similar…
Figure 17
Figure 17. Figure 17: The energy dependence of lag (upper panels) and coherence (lower panels) of the heartbeat states in 2021 (left) and 2023 (right). The reference energy band is 2–3 keV, and the comparison bands are 3–4 keV, 4–7 keV, and 7–12 keV. The yellow region highlights the freque…
Figure 18
Figure 18. Figure 18: The upper bound of the equivalent width of the the Fe XXV (upper panel) and Fe XXVI (lower panel) absorption line. The purple crosses show the spectra we identify with wind features from a below zero upper bound of either of the two lines [PITH_FULL_IMAGE:figures/ful…
Figure 19
Figure 19. Figure 19: The upper panel shows the the spectra of the heartbeat state in 2021 (left panel) and 2023 (right panel), along with spectra from observations taken before and after the heartbeat state. The lower panels show the residuals of the fits of these spectra with the model t…

Discussion (0). Continue with ORCID to comment.

Reference graph

Works this paper leans on

70 extracted references · 18 canonical work pages

  1. [1]

    2020, MNRAS, 497, 3896, doi: 10.1093/mnras/staa2168

    Alabarta, K., Altamirano, D., M´ endez, M., et al. 2020, MNRAS, 497, 3896, doi: 10.1093/mnras/staa2168

    doi:10.1093/mnras/staa2168 2020

  2. [2]

    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

  3. [3]

    2022, arXiv e-prints, arXiv:2209.07954, doi: 10.48550/arXiv.2209.07954

    Bachetti, M., & Huppenkothen, D. 2022, arXiv e-prints, arXiv:2209.07954, doi: 10.48550/arXiv.2209.07954

    arXiv doi:10.48550/arxiv.2209.07954 2022

  4. [4]

    R., van der Klis, M., & van Paradijs, J

    Belloni, T., M´ endez, M., King, A. R., van der Klis, M., & van Paradijs, J. 1997, ApJL, 488, L109, doi: 10.1086/310944 4U 1630–47 17

    doi:10.1086/310944 1997

  5. [5]

    Belloni, T. M. 2010, in Lecture Notes in Physics, Berlin Springer Verlag, ed. T. Belloni, Vol. 794, 53, doi: 10.1007/978-3-540-76937-8 3

    doi:10.1007/978-3-540-76937-8 2010

  6. [6]

    M., & Motta, S

    Belloni, T. M., & Motta, S. E. 2016, in Astrophysics and Space Science Library, Vol. 440, Astrophysics of Black Holes: From Fundamental Aspects to Latest Developments, ed. C. Bambi, 61, doi: 10.1007/978-3-662-52859-4 2

    doi:10.1007/978-3-662-52859-4 2016

  7. [7]

    M., Motta, S

    Belloni, T. M., Motta, S. E., & Mu˜ noz-Darias, T. 2011, Bulletin of the Astronomical Society of India, 39, 409, doi: 10.48550/arXiv.1109.3388

    arXiv doi:10.48550/arxiv.1109.3388 2011

  8. [8]

    2024, MNRAS, 528, 558, doi: 10.1093/mnras/stad3912

    Bollemeijer, N., Uttley, P., Basak, A., et al. 2024, MNRAS, 528, 558, doi: 10.1093/mnras/stad3912

    doi:10.1093/mnras/stad3912 2024

Show all 70 references
  1. [9]

    Buisson, D. J. K., Fabian, A. C., Barret, D., et al. 2019, MNRAS, 490, 1350, doi: 10.1093/mnras/stz2681

    2019 doi

  2. [10]

    2015, MNRAS, 450, 3840, doi: 10.1093/mnras/stv687

    Capitanio, F., Campana, R., De Cesare, G., & Ferrigno, C. 2015, MNRAS, 450, 3840, doi: 10.1093/mnras/stv687

    2015 doi

  3. [11]

    2005, ApJ, 629, 403, doi: 10.1086/431174

    Casella, P., Belloni, T., & Stella, L. 2005, ApJ, 629, 403, doi: 10.1086/431174

    2005 doi

  4. [12]

    2015, MNRAS, 447, 3960, doi: 10.1093/mnras/stu2742

    Choudhury, M., Bhatt, N., & Bhattacharyya, S. 2015, MNRAS, 447, 3960, doi: 10.1093/mnras/stu2742

    2015 doi

  5. [13]

    W., Done, C., & Blaes, O

    Davis, S. W., Done, C., & Blaes, O. M. 2006, ApJ, 647, 525, doi: 10.1086/505386 De Marco, B., Zdziarski, A. A., Ponti, G., et al. 2021, A&A, 654, A14, doi: 10.1051/0004-6361/202140567 D ´ ıaz Trigo, M., Migliari, S., Miller-Jones, J. C. A., &

    2006 doi

  6. [14]

    2014, A&A, 571, A76, doi: 10.1051/0004-6361/201424554

    Guainazzi, M. 2014, A&A, 571, A76, doi: 10.1051/0004-6361/201424554

    2014 doi

  7. [15]

    2007, A&A Rv, 15, 1, doi: 10.1007/s00159-007-0006-1

    Done, C., Gierli´ nski, M., & Kubota, A. 2007, A&A Rv, 15, 1, doi: 10.1007/s00159-007-0006-1

    2007 doi

  8. [16]

    2003, ApJ, 597, 780, doi: 10.1086/378586

    Ebisawa, K., ˙Zycki, P., Kubota, A., Mizuno, T., & Watarai, K.-y. 2003, ApJ, 597, 780, doi: 10.1086/378586

    2003 doi

  9. [17]

    C., Parker, M

    Fabian, A. C., Parker, M. L., Wilkins, D. R., et al. 2014, MNRAS, 439, 2307, doi: 10.1093/mnras/stu045

    2014 doi

  10. [18]

    2024, ApJ, 969, 61, doi: 10.3847/1538-4357/ad49a1 Garc ´ ıa, J., Dauser, T., Lohfink, A., et al

    Fan, N., Li, S., Zhan, R., et al. 2024, ApJ, 969, 61, doi: 10.3847/1538-4357/ad49a1 Garc ´ ıa, J., Dauser, T., Lohfink, A., et al. 2014, ApJ, 782, 76, doi: 10.1088/0004-637X/782/2/76

    2024 doi

  11. [19]

    2019, MNRAS, 482, 2597, doi: 10.1093/mnras/sty2850

    Migliari, S. 2019, MNRAS, 482, 2597, doi: 10.1093/mnras/sty2850

    2019 doi

  12. [20]

    M., Uttley, P., & Klein-Wolt, M

    Heil, L. M., Uttley, P., & Klein-Wolt, M. 2015, MNRAS, 448, 3339, doi: 10.1093/mnras/stv191

    2015 doi

  13. [21]

    2005, Ap&SS, 300, 107, doi: 10.1007/s10509-005-1197-4

    Homan, J., & Belloni, T. 2005, Ap&SS, 300, 107, doi: 10.1007/s10509-005-1197-4

    2005 doi

  14. [22]

    2018, The Astrophysical Journal, 869, 183, doi: 10.3847/1538-4357/aaea5e

    Hori, T., Ueda, Y., Done, C., Shidatsu, M., & Kubota, A. 2018, The Astrophysical Journal, 869, 183, doi: 10.3847/1538-4357/aaea5e

    2018 doi

  15. [23]

    R., & Motta, S

    Ingram, A. R., & Motta, S. E. 2019, NewAR, 85, 101524, doi: 10.1016/j.newar.2020.101524

    2019

  16. [24]

    Jones, C., Forman, W., Tananbaum, H., & Turner, M. J. L. 1976, ApJL, 210, L9, doi: 10.1086/182291

    1976 doi

  17. [25]

    2001, ApJS, 133, 221, doi: 10.1086/319184

    Kallman, T., & Bautista, M. 2001, ApJS, 133, 221, doi: 10.1086/319184

    2001 doi

  18. [26]

    E., Nandi, A., et al

    Katoch, T., Baby, B. E., Nandi, A., et al. 2021, MNRAS, 501, 6123, doi: 10.1093/mnras/staa3756

    2021 doi

  19. [27]

    L., Walton, D

    King, A. L., Walton, D. J., Miller, J. M., et al. 2014, ApJL, 784, L2, doi: 10.1088/2041-8205/784/1/L2

    2014 doi

  20. [28]

    2004, ApJ, 601, 428, doi: 10.1086/380433

    Kubota, A., & Makishima, K. 2004, ApJ, 601, 428, doi: 10.1086/380433

    2004 doi

  21. [29]

    1998, PASJ, 50, 667, doi: 10.1093/pasj/50.6.667

    Kubota, A., Tanaka, Y., Makishima, K., et al. 1998, PASJ, 50, 667, doi: 10.1093/pasj/50.6.667

    1998 doi

  22. [30]

    2007, in IAU

    Kubota, A., Dotani, T., Cottam, J., et al. 2007, in IAU

    2007

  23. [31]

    238, Black Holes from Stars to Galaxies – Across the Range of Masses, ed

    Symposium, Vol. 238, Black Holes from Stars to Galaxies – Across the Range of Masses, ed. V. Karas & G. Matt, 23–28, doi: 10.1017/S1743921307004620

    doi

  24. [32]

    M., Agrawal, V

    Kushwaha, A., Jayasurya, K. M., Agrawal, V. K., & Nandi, A. 2023, MNRAS, 524, L15, doi: 10.1093/mnrasl/slad070

    2023 doi

  25. [33]

    R., Narayan, R., & McClintock, J

    Li, L.-X., Zimmerman, E. R., Narayan, R., & McClintock, J. E. 2005, ApJS, 157, 335, doi: 10.1086/428089

    2005 doi

  26. [34]

    P., & Eardley, D

    Lightman, A. P., & Eardley, D. M. 1974, ApJL, 187, L1, doi: 10.1086/181377

    1974 doi

  27. [35]

    2022, Astrophys

    Liu, H., Fu, Y., Bambi, C., et al. 2022, Astrophys. J., 933, 122, doi: 10.3847/1538-4357/ac74b1

    2022 doi

  28. [36]

    2023, ApJ, 950, 5, doi: 10.3847/1538-4357/acca17

    Liu, H., Bambi, C., Jiang, J., et al. 2023, ApJ, 950, 5, doi: 10.3847/1538-4357/acca17

    2023 doi

  29. [37]

    2022, MNRAS, 512, 2082, doi: 10.1093/mnras/stac616

    Liu, Q., Liu, H., & Bambi, C. 2022, MNRAS, 512, 2082, doi: 10.1093/mnras/stac616

    2022 doi

  30. [38]

    Lyubarskii, Y. E. 1997, MNRAS, 292, 679, doi: 10.1093/mnras/292.3.679

    1997 doi

  31. [39]

    2021, Nature Astronomy, 5, 94, doi: 10.1038/s41550-020-1192-2

    Ma, X., Tao, L., Zhang, S.-N., et al. 2021, Nature Astronomy, 5, 94, doi: 10.1038/s41550-020-1192-2

    2021 doi

  32. [40]

    M., Fabian, A

    Miller, J. M., Fabian, A. C., Kaastra, J., et al. 2015, ApJ, 814, 87, doi: 10.1088/0004-637X/814/2/87

    2015 doi

  33. [41]

    M., Raymond, J., Fabian, A

    Miller, J. M., Raymond, J., Fabian, A. C., et al. 2016, ApJL, 821, L9, doi: 10.3847/2041-8205/821/1/L9

    2016 doi

  34. [42]

    1984, PASJ, 36, 741

    Mitsuda, K., Inoue, H., Koyama, K., et al. 1984, PASJ, 36, 741

    1984

  35. [43]

    A., & Lee, J

    Neilsen, J., Remillard, R. A., & Lee, J. C. 2011, ApJ, 737, 69, doi: 10.1088/0004-637X/737/2/69 —. 2012, ApJ, 750, 71, doi: 10.1088/0004-637X/750/1/71

    2011 doi

  36. [44]

    R., et al

    Pahari, M., Bhattacharyya, S., Rao, A. R., et al. 2018, ApJ, 867, 86, doi: 10.3847/1538-4357/aae53b

    2018 doi

  37. [45]

    2014, MNRAS, 442, 1767, doi: 10.1093/mnras/stu867

    Coriat, M. 2014, MNRAS, 442, 1767, doi: 10.1093/mnras/stu867

    2014 doi

  38. [46]

    Raj, A., & Nixon, C. J. 2021, ApJ, 909, 82, doi: 10.3847/1538-4357/abdc25

    2021 doi

  39. [47]

    2024, ApJ, 964, 77, doi: 10.3847/1538-4357/ad226e 18 F an et al

    Ratheesh, A., Dovˇ ciak, M., Krawczynski, H., et al. 2024, ApJ, 964, 77, doi: 10.3847/1538-4357/ad226e 18 F an et al

    2024 doi

  40. [48]

    Rawat, D., Misra, R., Jain, P., & Yadav, J. S. 2022, MNRAS, 511, 1841, doi: 10.1093/mnras/stac154

    2022 doi

  41. [49]

    A., Morgan, E

    Remillard, R. A., Morgan, E. H., McClintock, J. E., Bailyn, C. D., & Orosz, J. A. 1999, ApJ, 522, 397, doi: 10.1086/307606

    1999 doi

  42. [50]

    A., Loewenstein, M., Steiner, J

    Remillard, R. A., Loewenstein, M., Steiner, J. F., et al. 2022, AJ, 163, 130, doi: 10.3847/1538-3881/ac4ae6

    2022 doi

  43. [51]

    2014, ApJ, 789, 57, doi: 10.1088/0004-637X/789/1/57

    Seifina, E., Titarchuk, L., & Shaposhnikov, N. 2014, ApJ, 789, 57, doi: 10.1088/0004-637X/789/1/57

    2014 doi

  44. [52]

    1995, ApJ, 445, 780, doi: 10.1086/175740

    Shimura, T., & Takahara, F. 1995, ApJ, 445, 780, doi: 10.1086/175740

    1995 doi

  45. [53]

    R., & Choi, C

    Sriram, K., Rao, A. R., & Choi, C. S. 2016, ApJ, 823, 67, doi: 10.3847/0004-637X/823/1/67

    2016 doi

  46. [54]

    F., McClintock, J

    Steiner, J. F., McClintock, J. E., Remillard, R. A., et al. 2010, ApJL, 718, L117, doi: 10.1088/2041-8205/718/2/L117

    2010 doi

  47. [55]

    Stiele, H., & Kong, A. K. H. 2020, ApJ, 889, 142, doi: 10.3847/1538-4357/ab64ef

    2020 doi

  48. [56]

    2001, Astrophysics and Space Science Supplement, 276, 201, doi: 10.1023/A:1011659800688

    Swank, J. 2001, Astrophysics and Space Science Supplement, 276, 201, doi: 10.1023/A:1011659800688

    2001 doi

  49. [57]

    P., Borozdin, K

    Trudolyubov, S. P., Borozdin, K. N., & Priedhorsky, W. C. 2001, MNRAS, 322, 309, doi: 10.1046/j.1365-8711.2001.04073.x

    2001

  50. [58]

    M., Kaastra, J., et al

    Trueba, N., Miller, J. M., Kaastra, J., et al. 2019, ApJ, 886, 104, doi: 10.3847/1538-4357/ab4f70

    2019 doi

  51. [59]

    2024, MNRAS, doi: 10.1093/mnras/stae2514

    Uttley, P., & Malzac, J. 2024, MNRAS, doi: 10.1093/mnras/stae2514

    2024 doi

  52. [60]

    2011, MNRAS, 414, L60, doi: 10.1111/j.1745-3933.2011.01056.x van der Klis, M

    Uttley, P., Wilkinson, T., Cassatella, P., et al. 2011, MNRAS, 414, L60, doi: 10.1111/j.1745-3933.2011.01056.x van der Klis, M. 1995, in X-ray Binaries, ed. W. H. G

    2011

  53. [61]

    A., Ferland, G

    Verner, D. A., Ferland, G. J., Korista, K. T., & Yakovlev, D. G. 1996, ApJ, 465, 487, doi: 10.1086/177435

    1996 doi

  54. [62]

    2021, ApJL, 910, L3, doi: 10.3847/2041-8213/abec79

    Wang, J., Mastroserio, G., Kara, E., et al. 2021, ApJL, 910, L3, doi: 10.3847/2041-8213/abec79

    2021 doi

  55. [63]

    A., et al

    Wang, J., Kara, E., Garc ´ ıa, J. A., et al. 2024, ApJ, 963, 14, doi: 10.3847/1538-4357/ad1595

    2024 doi

  56. [64]

    A., Steiner, J

    Wang-Ji, J., Garc ´ ıa, J. A., Steiner, J. F., et al. 2018, ApJ, 855, 61, doi: 10.3847/1538-4357/aaa974

    2018 doi

  57. [65]

    2000, The Astrophysical Journal, 542, 914, doi: 10.1086/317016

    Wilms, J., Allen, A., & McCray, R. 2000, The Astrophysical Journal, 542, 914, doi: 10.1086/317016

    2000 doi

  58. [66]

    2018, Monthly Notices of the Royal Astronomical Society, 474, 1214

    Yan, S.-P., Ji, L., Liu, S.-M., et al. 2018, Monthly Notices of the Royal Astronomical Society, 474, 1214

    2018

  59. [67]

    2022, ApJ, 937, 33, doi: 10.3847/1538-4357/ac84d6

    Yang, Z.-x., Zhang, L., Huang, Y., et al. 2022, ApJ, 937, 33, doi: 10.3847/1538-4357/ac84d6

    2022 doi

  60. [68]

    A., Szanecki, M., Poutanen, J., Gierli´ nski, M., & Biernacki, P

    Zdziarski, A. A., Szanecki, M., Poutanen, J., Gierli´ nski, M., & Biernacki, P. 2020, MNRAS, 492, 5234, doi: 10.1093/mnras/staa159

    2020 doi

  61. [69]

    2024, ApJ, 975, 22, doi: 10.3847/1538-4357/ad7b29

    Zhang, Z., Bambi, C., Liu, H., et al. 2024, ApJ, 975, 22, doi: 10.3847/1538-4357/ad7b29

    2024 doi

  62. [70]

    M., King, A

    Zoghbi, A., Miller, J. M., King, A. L., et al. 2016, ApJ, 833, 165, doi: 10.3847/1538-4357/833/2/165 ˙Zycki, P. T., Done, C., & Smith, D. A. 1999, MNRAS, 309, 561, doi: 10.1046/j.1365-8711.1999.02885.x

    2016

Pith tools

Reviewed August 11, 2026 · model on record in the stance chip above.