Pith. sign in

REVIEW 3 major objections 5 minor 33 references

Spectral Analysis of Cyg X-3 using simultaneous AstroSat and Insight-HXMT Observations

T0 review · 3 major / 5 minor · reviewed 2026-08-16 · deepseek-v4-flash

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

Pith's one-line read The soft-state X-ray spectrum of Cygnus X-3 is consistent with pure reflection of the intrinsic source off a funnel-shaped shroud, and the same funnel geometry can reproduce the polarization degrees observed in both the soft and hard…

desk verdict Competent spectral/funnel analysis of Cyg X-3 with an honest caveat at its core: the pure-reflection premise and the luminosity estimate that rides on it are not tested against a direct-component alternative. read the letter →

arxiv 2505.02982 v1 pith:IDQ5WJYJ submitted 2025-05-05 astro-ph.HE

Suraj K. Chaurasia , Gitika Mall , Ruchika Dhaka , Ranjeev Misra , Amit Pathak This is my paper · ORCID
classification astro-ph.HE
keywords CygnusX-3X-raypolarimetryfunnelgeometryreflectionspectrumsuper-Eddingtonaccretionbinariesdiskpolarizationdegree
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 simultaneous AstroSat and Insight-HXMT spectra of the X-ray binary Cygnus X-3 in its soft state, across 1–20 keV and through one 4.8-hour orbit. It argues that a pure reflection spectrum, with Gaussian lines for iron, silicon, and sulfur, fits the data well, with no orbital phase variation except overall normalization. Motivated by IXPE polarization measurements, the authors model the source as an accretion disk shrouded by a funnel-shaped outflow, and show that a single set of funnel parameters can produce both the ~12% polarization degree observed in the soft state (via scattering in the funnel volume) and the ~23% degree in the hard state (via reflection from the funnel walls). Comparing the funnel models to a plane-disk model raises the inferred intrinsic luminosity to a few times $10^{40}$ erg/s, which is super-Eddington for a stellar-mass compact object and places Cyg X-3 in the ultraluminous X-ray class. This picture ties spectroscopy, polarimetry, and geometry into one funnel-shaped model, at the cost of assuming the observer sees no direct light from the central source.

What carries the argument

The central object is the funnel geometry: a conical, optically thick channel through which the intrinsic source's radiation escapes — either by scattering off gas inside the funnel volume or by reflection from the funnel's inner walls. The argument is carried by an analytic radiative-transfer model that integrates the scattered/reflected intensity over the visible part of the funnel, using Thomson scattering's angle-dependent polarization (PD = (1−cos²ψ)/(1+cos²ψ)) and accounting for absorption along both the incoming and outgoing path. The model's output is a contour map of constant polarization degree as a function of observer inclination and funnel opening angle, plus flux ratios (Rf,s or Rf,r) that, when compared with the plane-parallel disk ratio Rd, determine how much higher the intrinsic luminosity must be than the plane-disk estimate.

What would settle it

A single simultaneous IXPE + broadband spectral observation that measures both the soft-state polarization degree and the iron line equivalent width would settle the picture: if the EW is close to 1 keV (cosmic abundance) or if the PD exceeds the scattering maximum of ~14.3% at 30° inclination, the pure-reflection/scattering funnel model as presented cannot be the whole story. Alternatively, detecting an orbital-phase modulation of the polarization degree or angle in excess of the model's predictions would falsify the fixed single-funnel geometry.

Watch

Extended reading notes

Core claim

On the paper's own terms, the central discovery is that Cygnus X-3's broadband soft-state spectrum can be described as a purely reflected/scattered component — using the XSPEC reflect model with rel_refl=-1, thermal Comptonization (thcomp) of disk blackbody seed photons, an edge near 9 keV, and Gaussian emission lines for S XVI at ~2.6 and ~3.3 keV, Si XIV at ~2.0 keV, and Fe Kα at ~6.8 keV — yielding reduced χ² near 1.1 for the full orbit. The spectral shape does not change across orbital phase except for normalization, which increases by a factor of about three between superior and inferior conjunction. Combining this with IXPE polarization results, the paper finds that reflection from the funnel walls can produce a polarization degree of 23% (hard state) but not 12%, while scattering within the funnel's gas produces 10–12% (soft state) but not 23%, at a fixed observer inclination of 30°; including absorption after scattering makes the polarization degree fall sharply as the funnel opening angle grows. There exist funnel parameters — inclination near 30° and moderate opening angles — that reproduce both observed polarization degrees under the two scenarios. By scaling the plane-disk reflected flux to the funnel-geometry flux, the intrinsic luminosity is estimated at ~7×$10^{40}$ erg/s for the scattering (12% PD) case and ~5×$10^{41}$ erg/s for the reflection (23% PD) case, possibly as low as ~$10^{40}$ erg/s if 23% PD is a lower limit.

Load-bearing premise

The load-bearing premise is that the observer sees no direct light from the intrinsic source in the soft state — the entire observed spectrum is reflected or scattered radiation from the funnel; the paper itself notes the fit may be phenomenological because the iron line is much weaker than pure reflection predicts.

Editorial extensions

If this is right

  • If the funnel interpretation holds, Cygnus X-3's intrinsic luminosity is roughly 10^40–10^41 erg/s, i.e., super-Eddington for a stellar-mass compact object, placing it among ultraluminous X-ray sources.
  • The same geometric model explains both the ~12% soft-state and ~23% hard-state polarization degrees without invoking state-dependent changes in geometry; only the dominant radiative process (scattering vs reflection) changes.
  • The lack of spectral variation across the orbit, combined with a factor ~3 normalization change, implies the orbital flux modulation is driven by the viewing geometry of the reflector/scatterer rather than by varying line-of-sight absorption.
  • The weakness of the iron line (EW ~0.1 keV) relative to pure reflection expectations (~1 keV) suggests iron depletion or that the reflection fit is partly phenomenological; discriminating between these requires tracking the line in other spectral states.
  • A broad-band, simultaneous polarimetric and spectral campaign would test whether the predicted PD–opening-angle relation holds across states, as the paper itself emphasizes.

Reading between the lines

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

  • If the funnel interpretation is right, the polarization angle should track the funnel axis orientation, and combined radio/X-ray polarization angle measurements could measure the jet-funnel alignment — a testable prediction not fully developed in the paper.
  • The rise in intrinsic luminosity by a factor ~25 over the plane-disk estimate implies that similar 'hidden' super-Eddington sources could be systematically under-luminous in apparent flux; population surveys might need to revisit Eddington-bias corrections for shrouded binaries.
  • The model's sensitivity of PD to absorption after scattering suggests that, at higher energies where absorption is weaker, the PD should rise; comparing PD energy dependence across the 2–8 keV band in a single IXPE observation could distinguish the scattering parameters.
  • The approach of matching two observed PDs with one funnel could be extended to the intermediate states of Cyg X-3, where the PD would be expected to interpolate between 12% and 23% if the funnel stays fixed.
Share X Bluesky LinkedIn Reddit HN

Signed reviews

No signed human review yet.

Editorial analysis

A structured set of objections, weighed in public.

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

Referee Report

3 major / 5 minor

Summary. The paper presents a broadband (1–20 keV) spectral analysis of Cygnus X-3 using simultaneous AstroSat (SXT, LAXPC20) and Insight-HXMT (LE, ME) observations covering one 4.8-hour orbital cycle during the soft state. The adopted spectral model is tbabs*(reflect*edge*thcomp*diskbb + four Gaussian lines), with rel_refl fixed to -1, so that the fitted continuum is a pure reflection component with no direct emission. The fit is statistically good (χ²/dof ≈ 1.1), and orbital phase-resolved fitting shows no significant parameter variation except normalization. Motivated by IXPE polarization results, the authors then construct an analytic funnel model with two scenarios: scattering inside the funnel volume (with and without post-scattering absorption) and reflection from the funnel walls. They compute scattered/reflected flux ratios and polarization degrees as functions of funnel parameters and observer inclination, calibrate the model to reproduce the observed soft-state PD of ~12% and hard-state PD of ~23%, and infer intrinsic luminosities of ~7×10^40 erg/s for the scattering scenario and ~5×10^41 erg/s for the reflection scenario, with a possible reduction to ~10^40 erg/s if 23% is a lower limit. The paper explicitly notes that the IXPE data are not simultaneous with the AstroSat/HXMT observations and that the weak Fe line (EW ~0.1 keV) may make the pure-reflection fit phenomenological.

Significance. If the central premise is accepted, the paper would strengthen the case that Cygnus X-3 is viewed through a funnel-like scattering/reflection geometry and that its intrinsic luminosity is super-Eddington. The work has several genuine strengths: it uses simultaneous multi-instrument broadband data, provides a detailed analytic treatment of the funnel geometry with explicit radiative transfer in the appendix, reproduces the earlier Veledina et al. conclusions for the no-absorption scattering case, and is commendably explicit about its limitations in Section 6. However, the significance of the luminosity and geometry claims is conditional on the pure-reflection assumption, which is not tested against a model containing a direct component. The paper's own stated Fe-line equivalent-width discrepancy and the possibility that the fit is phenomenological mean that the central interpretive step is currently an assumption rather than a demonstrated result.

major comments (3)
  1. [§3, Table 2, §6] The load-bearing assumption that the observed spectrum is purely reflected/scattered light with no direct view of the intrinsic source is imposed rather than tested. In the XSPEC model, rel_refl is fixed to -1, which forces the continuum to contain only the reflection component; no alternative model with a free reflection fraction or an added direct component is fitted and compared. The paper's own Section 6 acknowledges that the fitted Fe Kα line equivalent width (~0.1 keV) is far below the ~1 keV expected for pure reflection and that the fit 'may be of a phenomenological nature rather than a physically motivated one.' Since the luminosity estimates in Section 5 and the polarization-to-geometry mapping in Section 4 both scale with the reflected fraction, the central claim is not yet supported unless the pure-reflection hypothesis is tested against a model that allows a direct component.
  2. [§5, Eqs. (1)-(6), Tables 3-4] The intrinsic luminosity estimates are conditional on funnel parameters that are calibrated to reproduce the observed IXPE polarization degrees, so the luminosity is inferred from the very quantity the model is meant to explain. For the scattering model, the six rows of Table 3 show a factor of ~1.8 spread in luminosity (7.15–13.2 × 10^40 erg/s) while remaining within the 10.8–12.4% PD band, and the quoted ~7×10^40 erg/s corresponds to one selected configuration. No uncertainty or degeneracy band is propagated into the luminosity from the range of funnel parameters, inclinations, or PD errors. The paper should present the luminosity as a range over acceptable parameter sets, and should assess how the luminosity changes if a small direct component is admitted.
  3. [§2, §6, §4] The IXPE polarization measurements used for calibrating the funnel geometry were not simultaneous with the AstroSat/Insight-HXMT observations, as the paper itself states in Section 6. Cygnus X-3 is highly variable, and the soft-state PD values from Veledina et al. (2024b) are from a different epoch than the spectra analyzed here. The mapping from observed PD to funnel parameters therefore carries an unquantified systematic uncertainty from source variability, and the resulting luminosity estimates inherit that uncertainty. The paper should either restrict the claimed quantitative results to the epochs covered, or provide a sensitivity estimate showing how the inferred luminosities vary when the input PD is varied within the IXPE measurement errors and between epochs.
minor comments (5)
  1. [Abstract and §3] The abstract describes 'emission lines of iron, silica, and sulfur,' but the text refers to Si XIV and S XVI lines; 'silica' should be 'silicon' to avoid confusion with SiO2.
  2. [Appendix A.3, Eq. (A16)] Equation (A16) contains a typo: the polarization degree for Thomson scattering should be PD = (1 − cos²ψ)/(1 + cos²ψ), but the printed denominator reads '1 − cos²ψ', which would give an undefined or incorrect result.
  3. [Figure 6] The red band in Figure 6 is labeled '10.8◦–12.4◦'; this should be '10.8%–12.4%' since it denotes polarization degree, not an angle.
  4. [Table 2] The table header 'Diskbb Norm (10 3)' and several line-normalization columns use inconsistent scientific notation; these should be unified (e.g., 10^−3) for readability.
  5. [§1 and §6] The statement in Section 1 that the funnel opening angle is 'less than 15°' from Veledina et al. should be cross-checked with the funnel-model parameters used in Tables 3–4, where opening angles of up to 16° appear; a brief comment on this apparent consistency or difference would help the reader.

Circularity Check

0 steps flagged · score 0.0 of 10

No significant circularity: the funnel-model luminosity is conditional on external IXPE polarization constraints, not forced by them, and the spectral fit is independent of the funnel geometry modeling.

full rationale

The paper's derivation chain is self-contained rather than circular. The spectral fit in Section 3 is a standard XSPEC analysis in which the reflection model is externally motivated by IXPE polarization results; the parameter rel_refl is fixed to -1, which means the model is constrained to be reflection-dominated, but the quality of the fit and the resulting parameter values are empirical outputs, not predictions derived from the funnel model. The funnel-model polarization calculations in Section 4 and Appendix A are forward integrations over a prescribed geometry, and the observed polarization degrees (12% in the soft state, 23% in the hard state) are used as external constraints to select or identify funnel parameters, not as outputs fitted to the AstroSat/Insight-HXMT spectra. The luminosity estimates in Section 5 follow from equating the observed scattered flux to the model flux and using the ratio Rd/Rf,s; the resulting luminosity varies across Table 3 rows even for similar polarization degrees, so it is not determined by the polarization constraint alone. The funnel geometry is taken from Veledina et al. (2024a,b), which is independent IXPE work, and the authors do not rely on a self-citation chain for the central result; the only self-citations (e.g., LAXPC calibration references) are instrumental and non-load-bearing. The paper itself flags the main weakness: the Fe line equivalent width of about 0.1 keV is weaker than the roughly 1 keV expected for pure reflection, and it acknowledges that the fit may be phenomenological rather than physically motivated. That is an assumption or correctness risk, not a circular reduction by construction. The paper also explicitly notes that the IXPE observations were not simultaneous with the spectra, which is a limitation but not a circularity. No equation in the paper reduces to its own input by definition, and no fitted parameter is renamed as a prediction, so the appropriate score is 0.

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

The central spectral fit rests on a flexible model with many fitted parameters. The funnel-model luminosity and PD results rest on a cone geometry, a fixed 30-degree inclination, a 9.7 kpc distance, a fixed 0.3 solar iron abundance, and single-scattering Thomson physics, none of which are independently verified in this paper. The funnel parameters are calibrated to the IXPE polarization measurements, so the luminosity numbers inherit that calibration.

free parameters (5)
  • Funnel optical depth at base radius (tau_rho) = 0.01-0.05 (Table 3)
    Chosen by hand to reproduce the IXPE soft-state PD of about 12% in the scattering model; drives the scattered flux ratio Rf,s and hence the inferred luminosity.
  • Lower height boundary optical depth (tau_z,min) = 0.1-0.2 (Table 3)
    Chosen by hand to match observed PD; together with tau_rho and xi sets the scattering geometry.
  • Funnel opening angle (xi or alpha) = 10-16 deg (scattering), 7.8-11.2 deg (reflection) (Tables 3, 4)
    Chosen by hand; controls the polarization degree and the common-parameter overlap claim.
  • Reflector upper-edge distance (R) = 10-30 units of base radius (Table 4)
    Chosen by hand in the reflection model to obtain 23% PD; directly controls reflected flux ratio and luminosity.
  • Broadband spectral fit parameters = NH about 2.2e22 cm^-2, Gamma about 5.5-5.9, kTin about 0.9 keV, diskbb norm about 12-37e3, edge about 9 keV, tau about…
    Fitted to the AstroSat/HXMT spectra in Table 2; the spectral claim rests on this fit, which has many correlated parameters.
assumptions (6)
  • domain assumption Funnel-shaped geometry with an optically thick medium shrouding the central source and half-opening angle less than 15 degrees
    Adopted from Veledina et al. 2024a,b; the entire PD and luminosity inference in Sections 4-5 and the Appendix assumes this geometry.
  • domain assumption Observer inclination i = 30 degrees
    Fixed from prior photoionization and light-curve studies (Vilhu et al. 2009; Antokhin et al. 2022); the scattering luminosity estimates in Table 3 and the main text use i=30 deg, and the PD conclusions are inclination-dependent.
  • domain assumption Distance to Cygnus X-3 of 9.7 kpc
    Taken from Reid and Miller-Jones 2023; enters linearly in the luminosity calculation (Eq 5), so a 5% distance error changes luminosity by about 10%.
  • ad hoc to paper Iron abundance fixed at 0.3 solar and kTe fixed at 50 keV
    Fixed to make the reflection model match the weak observed Fe line and the steep soft-state spectrum; the authors acknowledge the Fe line weakness may indicate the fit is phenomenological (Section 6).
  • domain assumption Thomson single-scattering approximation for polarization and flux in the funnel
    The Appendix computes single-scattering Stokes intensities (Eqs A12-A19, A22-A25); multiple scattering and relativistic effects are ignored, which could alter PD and flux ratios.
  • standard math Plane-parallel reflection formula (Eq 1) as the calibration baseline
    Expression from Magdziarz and Zdziarski 1995 for a semi-infinite slab; used to define Rd and to compare funnel flux ratios for luminosity estimation, though the actual geometry is a funnel.

how reviews work

0 comments
Cite this review

Pith. "Pith review of Spectral Analysis of Cyg X-3 using simultaneous AstroSat and Insight-HXMT Observations." pith.science (2026). https://pith.science/paper/IDQ5WJYJ

@misc{pith2026250502982,
  author       = {Pith},
  title        = {Pith review of: Spectral Analysis of Cyg X-3 using simultaneous AstroSat and Insight-HXMT Observations},
  year         = {2026},
  howpublished = {\url{https://pith.science/paper/IDQ5WJYJ}},
  note         = {Machine review of arXiv:2505.02982}
}
abstract

We present the results from the spectral analysis of Cygnus X-3 using simultaneous data from AstroSat and Insight-HXMT during its soft state. A pure reflection spectrum, including emission lines of iron, silica, and sulfur, provides a good fit to the spectra. Orbital phase-resolved analysis shows no significant spectral parameter variations, except for the normalization. Leveraging IXPE polarization results, we model the funnel-shaped geometry and estimate scattered flux and observed polarization for various funnel parameters and observer inclinations. We consider two scenarios: reflection from the funnel walls and scattering by gas within the funnel. Our results reconfirm previous findings, showing that reflection can produce a high polarization degree (PD) of 23$\%$, but not a low PD of 12$\%$. Conversely, scattering can produce a PD of 10-12$\%$, but not as high as 23$\%$ for a fixed observer inclination of $30^\circ$. Scattering results align with previous findings without absorption, but with absorption, PD drops significantly with increasing funnel opening angle. Thus, we can identify common funnel parameters that can produce the different observed PDs in the soft and hard states. The intrinsic luminosity of the source was estimated by comparing the results from a plane disk and the funnel model, to be $\sim7$ $\times$ 10$^{40}$ erg/s for 12$\%$ PD (scattering) and $\sim5$ $\times$ 10$^{41}$ erg/s for 23$\%$ PD (reflection). However, for the reflection model, the luminosity may decrease to $\sim$ 10$^{40}$ erg/s when the 23$\%$ PD observed is taken as a lower limit.

Figures

Figures reproduced from arXiv: 2505.02982 by the authors.

Figure 1
Figure 1. Simultaneous lightcurve of Cygnus X-3 ob￾served by different instruments onboard AstroSat (SXT and LAXPC) and Insight-HXMT (LE). The lightcurve is plotted in counts per second, with Red, Green, and Blue markers showing LAXPC20, SXT, and LE lightcurves respectively. The grey vertical lines divide the complete orbit into three distinct orbital phases. off rigidity > 8 GeV, pointing offset angle < 0.1 degrees, and at l… view at source ↗
Figure 2
Figure 2. Hardness intensity diagram (HID) of Cygnus X-3 where 3-6 keV count rate is shown as a function of hardness ratio (ratio of count rate between 10-15 keV and 3-6 keV) using LAXPC20 lightcurve. unfolded spectra along with residuals are depicted in [PITH_FULL_IMAGE:figures/full_fig_p004_2.png] view at source ↗
Figure 3
Figure 3. Fitted joint spectra along with model components and residuals for full orbit in 1-20 keV energy band. Spectra were fitted using the model tbabs*reflect*thcomp*diskbb. The black, red, green, and blue markers represent SXT (1.0-7.0 keV), LAXPC20 (5.0-20.0 keV), LE (2.0-10.0 keV), and ME (10.0-20.0 keV) data, respectively [PITH_FULL_IMAGE:figures/full_fig_p005_3.png] view at source ↗
Figures from the paper (3 more)
Figure 4
Figure 4. Figure 4: Top left and right panels show the data to best-fit model ratios for declining and minimum orbital phases respectively. The bottom left and right panels show the data to best-fit model ratios for the rising phase and for the complete orbit respectively using the model …
Figure 5
Figure 5. Figure 5: Above panel shows the funnel geometry with the central source marked with black sphere at the bottom and the observer at an inclination i relative to the disk for the case of scattering taking place from the gas present inside the funnel volume. The gray shaded region …
Figure 6
Figure 6. Figure 6: Contours of constant PD for radiation undergoing single scattering from the funnel volume having half opening angle α and different observer inclinations i, are depicted in red. The top panel shows results where absorption after scattering is neglected, while the botto…

Discussion (0). Continue with ORCID to comment.

Reference graph

Works this paper leans on

33 extracted references · 1 canonical work pages

  1. [1]

    Agrawal, P. C. 2006, Advances in Space Research, 38, 2989, doi: 10.1016/j.asr.2006.03.038 —. 2017, Journal of Astrophysics and Astronomy, 38, 27, doi: 10.1007/s12036-017-9449-6

    doi:10.1016/j.asr.2006.03.038 2006

  2. [2]

    M., Yadav, J

    Antia, H. M., Yadav, J. S., Agrawal, P. C., et al. 2017, The Astrophysical Journal Supplement Series, 231, 10, doi: 10.3847/1538-4365/aa7a0e

    doi:10.3847/1538-4365/aa7a0e 2017

  3. [3]

    Tatarnikov, A. M. 2022, The Astrophysical Journal, 926, 123, doi: 10.3847/1538-4357/ac4047

    doi:10.3847/1538-4357/ac4047 2022

  4. [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. [5]

    2020, Science China

    Chen, Y., Cui, W., Li, W., et al. 2020, Science China

    2020

  6. [6]

    Physics, Mechanics, and Astronomy, 63, 249505, doi: 10.1007/s11433-019-1469-5

    doi:10.1007/s11433-019-1469-5

  7. [7]

    P., Belloni, T

    Fender, R. P., Belloni, T. M., & Gallo, E. 2004, MNRAS, 355, 1105, doi: 10.1111/j.1365-2966.2004.08384.x

    arXiv 2004

  8. [8]

    Giacconi, R., Gorenstein, P., Gursky, H., & Waters, J. R. 1967, ApJL, 148, L119, doi: 10.1086/180028

    doi:10.1086/180028 1967

Show all 33 references
  1. [9]

    2020, Journal of High Energy Astrophysics, 27, 44, doi: 10.1016/j.jheap.2020.02.008

    Guo, C.-C., Liao, J.-Y., Zhang, S., et al. 2020, Journal of High Energy Astrophysics, 27, 44, doi: 10.1016/j.jheap.2020.02.008

    2020 doi

  2. [11]

    S., & Bleeker, J

    Kaastra, J. S., & Bleeker, J. A. M. 2016, A&A, 587, A151, doi: 10.1051/0004-6361/201527395

    2016 doi

  3. [12]

    2019, The Astrophysical Journal, 874, 51, doi: 10.3847/1538-4357/ab09f8

    Kallman, T., McCollough, M., Koljonen, K., et al. 2019, The Astrophysical Journal, 874, 51, doi: 10.3847/1538-4357/ab09f8

    2019 doi

  4. [13]

    G., & Trushkin, S

    Pooley, G. G., & Trushkin, S. A. 2010, Monthly Notices of the Royal Astronomical Society, 406, 307, doi: 10.1111/j.1365-2966.2010.16722.x

    2010

  5. [14]

    2020, Background Model for the Low-Energy Telescope of Insight-HXMT

    Liao, J.-Y., Zhang, S., Chen, Y., et al. 2020, Background Model for the Low-Energy Telescope of Insight-HXMT. https://arxiv.org/abs/2004.01432

    2020 arXiv

  6. [15]

    2020, Science China

    Liu, C., Zhang, Y., Li, X., et al. 2020, Science China

    2020

  7. [16]

    Physics, Mechanics, and Astronomy, 63, 249503, doi: 10.1007/s11433-019-1486-x

    doi

  8. [17]

    Magdziarz, P., & Zdziarski, A. A. 1995, MNRAS, 273, 837, doi: 10.1093/mnras/273.3.837

    1995 doi

  9. [18]

    O., Cordova, F

    Mason, K. O., Cordova, F. A., & White, N. E. 1986, ApJ, 309, 700, doi: 10.1086/164638

    1986 doi

  10. [19]

    G., & Waltman, E

    Pooley, G. G., & Waltman, E. B. 2001, ApJ, 553, 766, doi: 10.1086/320965

    2001 doi

  11. [20]

    1984, PASJ, 36, 741 NASA High Energy Astrophysics Science Archive Research Center (HEASARC)

    Mitsuda, K., Inoue, H., Koyama, K., et al. 1984, PASJ, 36, 741 NASA High Energy Astrophysics Science Archive Research Center (HEASARC). 2014, HEASoft: Unified Release of FTOOLS and XANADU. https://heasarc.gsfc.nasa.gov/lheasoft/

    1984

  12. [21]

    J., & Miller-Jones, J

    Reid, M. J., & Miller-Jones, J. C. A. 2023, The Astrophysical Journal, 959, 85, doi: 10.3847/1538-4357/acfe0c

    2023 doi

  13. [22]

    P., Stewart, G

    Singh, K. P., Stewart, G. C., Chandra, S., et al. 2016, in Society of Photo-Optical Instrumentation Engineers (SPIE) Conference Series, Vol. 9905, Space Telescopes and Instrumentation 2016: Ultraviolet to Gamma Ray, ed. J.-W. A. den Herder, T. Takahashi, & M. Bautz, 99051E, do...

    2016 doi

  14. [23]

    P., Stewart, G

    Singh, K. P., Stewart, G. C., Westergaard, N. J., et al. 2017, Journal of Astrophysics and Astronomy, 38, 29, doi: 10.1007/s12036-017-9448-7

    2017 doi

  15. [24]

    A., & McCollough, M

    Szostek, A., Zdziarski, A. A., & McCollough, M. L. 2008, Monthly Notices of the Royal Astronomical Society, 388, 1001, doi: 10.1111/j.1365-2966.2008.13479.x

    2008

  16. [25]

    1995, A&A, 294, 443 van Kerkwijk, M

    Terasawa, N., & Nakamura, H. 1995, A&A, 294, 443 van Kerkwijk, M. H., Charles, P. A., Geballe, T. R., et al. 1992, Nature, 355, 703, doi: 10.1038/355703a0

    1995 doi

  17. [26]

    2024a, Nature Astronomy, doi: 10.1038/s41550-024-02294-9

    Veledina, A., Muleri, F., Poutanen, J., et al. 2024a, Nature Astronomy, doi: 10.1038/s41550-024-02294-9

    doi

  18. [27]

    2024b, Ultrasoft state of microquasar Cygnus X-3: X-ray polarimetry reveals the geometry of astronomical puzzle

    Veledina, A., Poutanen, J., Bocharova, A., et al. 2024b, Ultrasoft state of microquasar Cygnus X-3: X-ray polarimetry reveals the geometry of astronomical puzzle. https://arxiv.org/abs/2407.02655

    arXiv

  19. [28]

    C., McCollough, M., & Koljonen, K

    Vilhu, O., Hakala, P., Hannikainen, D. C., McCollough, M., & Koljonen, K. 2009, A&A, 501, 679, doi: 10.1051/0004-6361/200811293

    2009 doi

  20. [29]

    E., & Holt, S

    White, N. E., & Holt, S. S. 1982, ApJ, 257, 318, doi: 10.1086/159991

    1982 doi

  21. [30]

    2000, ApJ, 542, 914, doi: 10.1086/317016 12

    Wilms, J., Allen, A., & McCray, R. 2000, ApJ, 542, 914, doi: 10.1086/317016 12

    2000 doi

  22. [31]

    S., Misra, R., Chauhan, J

    Yadav, J. S., Misra, R., Chauhan, J. V., et al. 2016, The Astrophysical Journal, 833, 27, doi: 10.3847/0004-637X/833/1/27

    2016 doi

  23. [32]

    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

  24. [33]

    2020, Science China

    Zhang, S.-N., Li, T., Lu, F., et al. 2020, Science China

    2020

  25. [34]

    ANALYTICAL MODELING OF FUNNEL GEOMETRY This work includes the funnel geometry proposed by Veledina et al

    Physics, Mechanics, and Astronomy, 63, 249502, doi: 10.1007/s11433-019-1432-6 13 APPENDIX A. ANALYTICAL MODELING OF FUNNEL GEOMETRY This work includes the funnel geometry proposed by Veledina et al. 2024a, which suggests that a funnel with small opening angles can account for ...

    doi

Pith tools

Reviewed August 16, 2026 · model on record in the stance chip above.