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Spectro-temporal Investigation of Quasi-periodic Oscillations From Black Hole X-ray Binary 4U 1630-472 Using $\textit{NICER}$

T0 review · 4 major / 4 minor · reviewed 2026-08-10 · deepseek-v4-flash

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Pith's one-line read In the black hole X-ray binary 4U 1630-472, type-C quasi-periodic oscillations change their coherence sharply at a critical frequency near 2.31 Hz, and the photon index of the corona tracks QPO frequency with r=0.97.

desk verdict A careful NICER study of type-C QPOs in the 2021 outburst of 4U 1630–472, with a genuinely new time-resolved QPO sequence and a plausible but under-supported claim of a 2.31 Hz break. read the letter →

arxiv 2501.13163 v1 pith:GY35DYLF submitted 2025-01-22 astro-ph.HE

Ansh Chopra , Manoneeta Chakraborty , Unnati Kashyap This is my paper · ORCID
classification astro-ph.HE
keywords blackholeX-raybinarytype-Cquasi-periodicoscillations4U1630-472NICERQ-factorcriticalfrequencyspectral-timingcorrelationaccretiondiskcorona
verification ladder T0 review T1 audit T2 compute T3 formal

The pith

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

The reading

This paper uses NICER X-ray timing and spectral data from three outbursts of the black hole X-ray binary 4U 1630-472 to establish that, during the rising phase of the 2021 outburst, type-C quasi-periodic oscillations evolve in a highly ordered way: their frequency is tightly correlated with the total flux (r=0.99) and with the photon index of the non-thermal coronal emission (r=0.97, p~1e-13). The central new claim is a sharp break at a critical frequency of approximately 2.31 Hz: below it the QPO coherence (Q-factor) rises with frequency, above it the slope reverses, and an F-test gives a chance probability of 6.96e-8 that a broken line is not required. The break coincides with the moment the photon index consistently exceeds 2 and is interpreted as a transition in the underlying physical mechanism, possibly the Low/Hard to Hard-Intermediate state change or a switch between competing QPO generation models. If correct, the result ties the QPO frequency to the coronal geometry and mass accretion rate, making the 2.31 Hz break a marker of an accretion-state transition that could be searched for in other black hole binaries.

What carries the argument

The central object is the type-C low-frequency quasi-periodic oscillation, quantified by centroid frequency $\nu_{qpo}$, fractional RMS, and Q-factor ($Q = \nu_0/2\Delta$, the ratio of centroid frequency to Lorentzian width). The analysis method that carries the argument is time-resolved power spectral analysis: rather than relying on time-averaged PDS, the authors split each observation into individual orbit segments, track a single QPO frequency as it drifts, and fit Lorentzians to each segment. The critical-frequency claim rests on comparing a straight-line and a two-slope broken-line fit to Q-factor versus $\nu_{qpo}$ with an F-test.

What would settle it

Rebin the same 2021 NICER observations using different segment boundaries, for example shorter or longer than the orbit segments, and re-fit the Q-factor versus frequency relation; if the broken-line fit is no longer strongly preferred over a straight line, or the break moves outside the 2-3 Hz range, the claimed critical frequency lacks robustness. Alternatively, look for the same break in a second outburst of this source or in another black hole X-ray binary with comparable NICER coverage.

Watch

Extended reading notes

Core claim

This paper reports that during the rising phase of the 2021 outburst of 4U 1630-472, 21 type-C QPOs form a sequence in which QPO frequency, photon index, non-thermal flux, hardness ratio, and fractional RMS evolve together; in particular, the coherence measured by the Q-factor ($\nu_0/2\Delta$) stops rising with frequency above $\nu_c \sim 2.31$ Hz and instead falls, with an F-test chance probability of $6.96\times 10^{-8}$ for a broken line against a straight line. The photon index of the Comptonizing corona correlates with QPO frequency at $r=0.97$ ($p\sim10^{-13}$), and total flux correlates at $r=0.99$. The same 2.31 Hz epoch is identified with the third orbit segment of MJD 59476.659, after which $\Gamma$ stays above 2, and the authors interpret the break as a transition in the physical mechanism, possibly connected to the Low/Hard to Hard-Intermediate state transition or a switch between Lense-Thirring precession and variable Comptonization regimes.

Load-bearing premise

The claim rests on the assumption that the multiple closely spaced peaks sometimes seen in a time-averaged power spectrum are one and the same QPO drifting in frequency during the observation, and that each orbit segment can be assigned a single roughly constant frequency; if real, distinct QPO components were present instead, the frequency sequence and the derived 2.31 Hz break would not be meaningful.

Editorial extensions

If this is right

  • If the break at ~2.31 Hz is real, the QPO coherence evolution can be used as a state indicator: it marks the Low/Hard to Hard-Intermediate transition in 4U 1630-472.
  • The tight $\Gamma$–$\nu_{qpo}$ correlation (r=0.97) means QPO frequency can serve as a proxy for the coronal temperature or the radius of the Comptonizing region during the rising phase.
  • The disappearance of type-C QPOs during flux surges, and their replacement by weaker sub-Hz QPOs, implies a rapid reconfiguration of the inner accretion flow when the flux crosses a threshold near $10^{-8}$ erg cm$^{-2}$ s$^{-1}$.
  • The comparison with models shows the critical frequency can be used to discriminate between Lense-Thirring precession and variable Comptonization as the dominant mechanism, though the paper stops short of a definitive choice.
  • The break near 2.31 Hz is consistent with similar breaks reported around 2-3 Hz in other black hole X-ray binaries, suggesting a common physical scale in these systems.

Reading between the lines

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

  • If the break tracks the spectral state rather than a fixed frequency, then in fainter or brighter outbursts of the same source the critical frequency should shift in proportion to the QPO frequency range observed; this is a testable extension the paper does not make.
  • The near-unity total-flux correlation (r=0.99) suggests QPO frequency is effectively a tracer of mass accretion rate; one could attempt to calibrate $\nu_{qpo}$ against an independent accretion-rate estimator such as the diskbb normalization to convert the 2.31 Hz break into a critical luminosity.
  • The weak 0.27-0.77 Hz QPOs seen after the second flux surge are not classifiable as type-A, B, or C; if future simultaneous radio observations show a jet ejection at that epoch, they would support the jet-precession interpretation for type-B-like QPOs.
  • A similar orbit-by-orbit analysis applied to archival NICER data of other black hole binaries could test whether the segmentation procedure itself creates spurious frequency drift; the paper's method assumes the drift is real.
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Editorial analysis

A structured set of objections, weighed in public.

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

Referee Report

4 major / 4 minor

Summary. This paper presents a spectro-timing analysis of NICER observations of the black hole X-ray binary 4U 1630-472 across its 2018, 2020, and 2021 outbursts. For the 2021 rising phase, the authors identify 21 type-C QPOs by extracting power spectra from individual orbit segments, and they study correlations between QPO frequency and spectral/timing parameters. They report a strong correlation between the photon index and QPO frequency (Pearson r=0.97), a break at ~2.31 Hz in the Q-factor versus frequency relation (with an F-test chance probability of 6.96e-8), and two flux surges associated with the disappearance of type-C QPOs, followed by weaker QPOs in softer states. The paper interprets the break as evidence for a transition in the physical mechanism governing the QPOs.

Significance. If the Q-factor break at ~2.31 Hz is genuine, the result is interesting because it suggests a characteristic frequency in the type-C QPO behavior of 4U 1630-472, possibly linked to a spectral state transition (LHS to HIMS) or a change in the corona geometry. The paper's orbit-resolved approach is a strength: it demonstrates that apparently multiple QPO peaks in time-averaged PDS come from a single evolving QPO, enabling a cleaner sample of 21 type-C QPOs. The strong photon-index correlation, if robust, extends similar correlations seen in other BHXBs to a broad frequency range. However, the statistical evidence for the break is currently weakened by data-dependent breakpoint selection, non-independence of the 21 points, and unquantified intra-segment frequency drift. These issues are identifiable and addressable, so the underlying observational dataset retains value.

major comments (4)
  1. [§3.4, Table 3] The F-test probability of 6.96e-8 for the Q-factor break is computed with the breakpoint fixed at 2.31 Hz, but that breakpoint is selected from the same data (it coincides with the highest-significance QPO at MJD 59476.407, Table 1). The likelihood-ratio statistic does not follow the standard F distribution when the breakpoint is estimated rather than known; the reported p-value is therefore an in-sample statistic. Please re-assess the significance by (i) treating the breakpoint as a free parameter in a segmented regression and obtaining the null distribution via Monte Carlo simulation of the straight-line model (or a permutation/bootstrap test that preserves the correlation structure), or (ii) adopting a Bayesian information criterion or a Bayesian model comparison with appropriate priors on the breakpoint. In addition, since five relations are tested in Table 3, a multiple-comparison correction should be stated. As written, the claim that the break is 'significantly detectable (beyond 3σ)' is not established by the current F-test.
  2. [§3.2.1, Table 1] The 21 type-C QPOs are not independent measurements: several rows in Table 1 come from the same NICER OBSID (for example, OBSID 4130010107 contributes three rows, and OBSIDs 4130010104, 4130010111, 4130010112, and 4130010114 each contribute two or three rows). The chi-square fits in Table 3 treat these as independent, which overstates the information content and can make a single within-observation systematic appear as a physical break. In fact, the slope reversal in the Q-factor relation is driven largely by the drop from Q=12.58 at 2.315 Hz to Q=5.46 at 2.752 Hz within OBSID 4130010107 (MJD 59476.407 and 59476.659). Please re-fit the Q-factor and other relations using one representative point per OBSID (or a mixed-effects model that accounts for clustering), and report which points dominate the chi-square improvement. If the break disappears under this re-analysis, it should be interpreted as an intra-observation effect rather than a physical critical frequency.
  3. [§3.2.1, Figure 5] The Q-factor is defined as centroid/FWHM of the Lorentzian fit. Section 3.2.1 explicitly shows that the QPO centroid frequency evolves within a single observation (Figure 5), yet the table entries correspond to full orbit segments. If the centroid drifts within the segment, the time-averaged PDS peak broadens and the reported Q is artificially low. The authors do not quantify the intra-segment frequency drift for the segments in Table 1; in particular, the 2.752 Hz segment (which lies above the break) may contain stronger drift, producing a low Q that creates the appearance of a break at 2.31 Hz. Please provide, for each segment, an estimate of the frequency drift (for example, from splitting each segment into sub-segments) or a demonstration that drift is negligible on the segment timescale. This check is essential because the break is the paper's main physical conclusion.
  4. [§3.4, Table 3 and §3.3.2] There are two technical inconsistencies that affect the F-test. First, the degrees of freedom in Table 3 do not match the stated sample size and models: with 21 data points, a straight-line fit has 2 parameters and hence dof=19 (not 20), and a continuous broken line with a fixed breakpoint has 3 parameters and dof=18 (not 19). Please verify the number of points actually used in each fit and the exact functional form of the broken-line model (e.g., whether the breakpoint is free or fixed). Second, the text notes in Section 3.4 that 'the considerable error bars in HR values were not accounted for in the plot'; please state explicitly which uncertainties were propagated into the chi-square fits for each relation (Q-factor, RMS_frac, HR, Γ, F_NTh), including asymmetric errors on spectral parameters, and confirm that the fits account for all reported uncertainties. Without this, the chi-square values in Table 3 are not interpretable as goodness-of-fit statistics.
minor comments (4)
  1. [§3.5] The cross-reference 'shown in Figure 3 and discussed in Section§4.1' appears to be an error; the correlation analysis is presented in Figure 11, not Figure 3.
  2. [Table 1] The frequency column header is typeset as '𝝂𝒒 𝒑𝒐' with a spurious space; please use a consistent notation for ν_qpo throughout the table and text.
  3. [§4.1] The Pearson correlation coefficients r=0.97 for Γ-ν_qpo and r=0.99 for total flux are quoted with nominal p-values; since the 21 points are clustered by OBSID, report an effective number of independent measurements and a corrected p-value (for example, by averaging within OBSIDs or using a cluster-robust procedure).
  4. [§3.5] The F-test significance levels for the weak QPOs are quoted in units of sigma; please provide the F-test degrees of freedom as well so that readers can reproduce the conversion from p-values to Gaussian significance.

Circularity Check

0 steps flagged · score 0.0 of 10

No significant circularity: the paper reports empirical fits and observed correlations, with no derivation that reduces to its own inputs.

full rationale

This is an empirical spectro-timing analysis of NICER data. QPO parameters are obtained from Lorentzian fits to power density spectra, and the reported correlations and the critical frequency at ~2.31 Hz are descriptive statistics and fitted broken-line models applied to the measured sample. The critical frequency is explicitly described as observed, not predicted, and no equation in the paper defines any output quantity as equivalent to an input quantity by construction. Methodological citations are to standard tools (Belloni et al. 2002 for Lorentzian modeling, Leahy et al. 1983 for normalization, Motta et al. 2011 for significance), and external comparison studies are used only for context. There is no load-bearing self-citation: the authors do not invoke a prior result by themselves to justify a premise, and no uniqueness theorem or ansatz is imported from their own earlier work. The in-sample choice of the breakpoint before applying the F-test is a statistical model-selection concern, not a circularity of the kind defined here, since the claim is a fit to the data rather than a prediction forced by the fitting procedure. The paper also acknowledges its own limitations, such as NICER's reduced sensitivity at higher energies and the degeneracy of thermal parameters in hard states. Accordingly, no step in the derivation chain reduces to its own inputs, and the appropriate finding is no significant circularity.

Assumptions & free parameters 3 free parameters · 5 assumptions · 0 invented entities

The central claims rest on a modest set of empirical fits: the critical frequency and broken-line slopes are free parameters fitted to the same 2021 data, while the QPO sample itself rests on an orbit-segmentation assumption. No genuinely new physical entity is introduced. The standard spectral parameters in Table 2 are also fitted, but they are conventional measurements.

free parameters (3)
  • Critical frequency nu_c (broken-line breakpoint) = ~2.31 Hz
    Estimated by fitting a two-slope broken line to the Q-factor versus QPO frequency data for 2021 type-C QPOs; the same value is then used as the break for the other four relations.
  • Broken-line slopes for Q-factor, RMS_frac, HR, Gamma, and F_Nth versus nu_qpo = Two slopes per relation, shown in Figure 11
    Empirical slopes before and after the break; fitted values are used to claim a transition at nu_c.
  • Spectral parameters (N_H, diskbb normalization, power-law normalization, photon index, fluxes) = Listed in Table 2
    Fitted to NICER spectra with TBABS*(POWERLAW*DISKBB); these measured values feed the correlations with QPO frequency.
assumptions (5)
  • domain assumption Lorentzians plus a zero-centered Lorentzian and constant describe the PDS continuum and QPO in Leahy-normalized power spectra.
    Invoked throughout Section 3.2 for QPO detection and parameter measurement; standard in the field but a modeling choice.
  • domain assumption Multiple peaks in a time-averaged PDS can be decomposed into a single QPO whose frequency drifts across orbits; each orbit segment has roughly constant QPO frequency.
    Section 3.2.1 and Figure 5; this justifies building the table of 21 type-C QPOs used for all correlations.
  • domain assumption The TBABS*(POWERLAW*DISKBB) spectral model over 2-10 keV provides unbiased estimates of Gamma and non-thermal flux in the hard state.
    Section 3.3; the authors note N_H degeneracy, unstable thermal parameters, and NICER's limited high-energy sensitivity.
  • domain assumption Pearson correlations on point estimates without propagating spectral uncertainties are meaningful for the reported p-values.
    Section 4.1 and Figure 11; errors in Table 2 are not propagated into r or p values.
  • ad hoc to paper The breakpoint at 2.31 Hz can be treated as fixed when assessing the broken-line model with F-tests across five relations.
    Table 3; the breakpoint is chosen after inspecting the data, and the extra dof count of one implies it is not marginalized or corrected for trials.

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Pith. "Pith review of Spectro-temporal Investigation of Quasi-periodic Oscillations From Black Hole X-ray Binary 4U 1630-472 Using $\textit{NICER}$." pith.science (2026). https://pith.science/paper/GY35DYLF

@misc{pith2026250113163,
  author       = {Pith},
  title        = {Pith review of: Spectro-temporal Investigation of Quasi-periodic Oscillations From Black Hole X-ray Binary 4U 1630-472 Using $\textitNICER$},
  year         = {2026},
  howpublished = {\url{https://pith.science/paper/GY35DYLF}},
  note         = {Machine review of arXiv:2501.13163}
}
abstract

We present a comprehensive analysis of the spectro-temporal characteristics of the X-ray variabilities from black hole X-ray binary 4U 1630-472 during its three outbursts (2018, 2020, and 2021) as observed by $\textit{NICER}$. We detected 27 Quasi-Periodic Oscillations (QPOs), out of which 25 were observed during the 2021 outburst. In this study, we specifically focus on the relationship between spectral and timing parameters and the frequency of type-C QPOs in the 2021 outburst of the black hole binary 4U 1630-472 during its rising phase. We found strong correlations between the photon index of the non-thermal emission and the QPO frequency. We also observed a critical frequency at $\sim$ 2.31 Hz, above which the behavior of the Q-factor of the QPO changed significantly with the QPO frequency. We further identified two events characterized by a surge in the total flux, corresponding to the disappearance of type-C QPOs. Although the first event appeared like an X-ray flare, during the second event, the source reached a state with a total flux higher than 10$^{-8}$ erg/cm$^{2}$/s and exhibited a different type of QPO with lower frequencies and weaker amplitudes. We compare our results with the previously reported QPO characteristics for black hole outbursts and discuss the various models that could interpret the critical frequency and potentially explain the origin and evolution of these type-C QPOs.

Figures

Figures reproduced from arXiv: 2501.13163 by the authors.

Figure 1
Figure 1. Long-term MAXI light curve (black) depicting the flux variations of 4U 1630–472 in the 2.0–20.0 keV energy range. The vertical lines (yellow) indicate the precise dates of the observations conducted by the NICER instrument. 2019 for three days during its peak, however, since the outbursts and the quasi-periodic variabilities in 2018, 2020, and 2021 had not yet been studied using NICER observations, we decided to foc… view at source ↗
Figure 2
Figure 2. Light curves (left) and HIDs (right) of the 2018, 2020, and 2021 outbursts of 4U 1630–472 observed by [PITH_FULL_IMAGE:figures/full_fig_p005_2.png] view at source ↗
Figure 3
Figure 3. The light curve corresponding to four consecutive observations from [PITH_FULL_IMAGE:figures/full_fig_p006_3.png] view at source ↗
Figures from the paper (10 more)
Figure 5
Figure 5. Figure 5: The light curve of the 2021 outburst from the [PITH_FULL_IMAGE:figures/full_fig_p006_5.png]
Figure 4
Figure 4. Figure 4: The power density spectra (PDS) of the type-C QPO observed on MJD [PITH_FULL_IMAGE:figures/full_fig_p006_4.png]
Figure 7
Figure 7. Figure 7: QPO fractional RMS as a function of the centroid frequency for the type-C QPOs observed in 2021. The shade of the data points indicates the mean count rate, as elaborated by the color bar. keV, and the High Energy (HE) band ranging from 6–10 keV. The choice of these en…
Figure 6
Figure 6. Figure 6: Temporal variations of key timing parameters of the QPOs de￾tected during the 2021 outburst. From top to bottom: Count Rate (0.2– 12 keV), QPO centroid frequency, Hardness Ratio (3.8–6.8 keV/2.0– 3.8 keV), Fractional RMS, and Q-factor are plotted with time. Regions mar…
Figure 8
Figure 8. Figure 8: RMS spectra showing the fractional RMS (in %) of all the QPOs detected during the rising phase of the 2021 outburst, across the three NICER energy bands 0.5–3 keV, 3–6 keV and 6–10 keV. The color in the plot represents the centroid frequency of the QPOs, following the …
Figure 9
Figure 9. Figure 9: Spectral fitting with TBABS(POWERLAW+DISKBB) model for OBSID 4130010102 (left) and OBSID 4130010118 (right) where 4U 1630–472 was in the hard and soft state respectively during its 2021 outburst. state. Interestingly, [PITH_FULL_IMAGE:figures/full_fig_p011_9.png]
Figure 10
Figure 10. Figure 10: The time-evolution of primary spectral parameters, from top to [PITH_FULL_IMAGE:figures/full_fig_p012_10.png]
Figure 12
Figure 12. Figure 12: Total Flux (in 2.0–10.0 keV range) as a function of type-C QPO frequency seen for 4U 1630–472 during its 2021 outburst. curves, are common in BHXBs. Tomsick and Kaaret (2000) detected LFQPOs during the decay phase of the 1998 outburst of 4U 1630–472 . However, no QPOs…
Figure 11
Figure 11. Figure 11: Dependence of Q-factor, 𝑅𝑀𝑆𝑓 𝑟𝑎𝑐, 𝐻𝑅 (3.8–6.8 keV/2.0–3.8 keV), Γ, and the non-thermal flux (2.0–10.0 keV range) on frequency of the type-C QPOs 𝜈𝑞 𝑝𝑜, observed for 4U 1630–472 during its 2021 outburst. The blue and red points are the estimated values of the source pa…
Figure 13
Figure 13. Figure 13: The PDS of the corresponding observations (a) type-C QPO, (b) the flaring event where the QPO is not visible, probably due to high count rates, and (c) [PITH_FULL_IMAGE:figures/full_fig_p014_13.png]

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Works this paper leans on

62 extracted references · 32 canonical work pages

  1. [1]

    The IR counterpart of the black-hole candidate 4U 1630-47

    author Augusteijn , T. , author Kuulkers , E. , author van Kerkwijk , M.H. , year 2001 . title The IR counterpart of the black-hole candidate 4U 1630-47 . journal volume 375 , pages 447--454 . :10.1051/0004-6361:20010855, http://arxiv.org/abs/astro-ph/0107337 arXiv:astro-ph/0107337

    work page Pith review arXiv 2001

  2. [2]

    AstroSat and MAXI view of the Black Hole binary 4U 1630-472 during 2016 and 2018 Outbursts

    author Baby , B.E. , author Agrawal , V.K. , author Ramadevi , M.C. , author Katoch , T. , author Antia , H.M. , author Mandal , S. , author Nandi , A. , year 2020 . title AstroSat and MAXI view of the black hole binary 4U 1630-472 during 2016 and 2018 outbursts . journal volume 497 , pages 1197--1211 . :10.1093/mnras/staa1965, http://arxiv.org/abs/2007.0...

    work page Pith review arXiv 2020

  3. [3]

    , author Garc \' a , F

    author Bellavita , C. , author Garc \' a , F. , author M \'e ndez , M. , author Karpouzas , K. , year 2022 . title vKompth: a variable Comptonization model for low-frequency quasi-periodic oscillations in black hole X-ray binaries . journal volume 515 , pages 2099--2109 . :10.1093/mnras/stac1922, http://arxiv.org/abs/2206.13609 arXiv:2206.13609

    arXiv 2022

  4. [4]

    , year 2002

    author Belloni , T. , year 2002 . title Timing Features in Black Hole Candidates , in: editor Gurzadyan , V.G. , editor Jantzen , R.T. , editor Ruffini , R. (Eds.), booktitle The Ninth Marcel Grossmann Meeting , pp. pages 2249--2250 . :10.1142/9789812777386_0539

    doi:10.1142/9789812777386_0539 2002

  5. [5]

    , author Homan , J

    author Belloni , T. , author Homan , J. , author Casella , P. , author van der Klis , M. , author Nespoli , E. , author Lewin , W.H.G. , author Miller , J.M. , author M \'e ndez , M. , year 2005 . title The evolution of the timing properties of the black-hole transient GX 339-4 during its 2002/2003 outburst . journal volume 440 , pages 207--222 . :10.1051...

    arXiv 2005

  6. [6]

    , author Psaltis , D

    author Belloni , T. , author Psaltis , D. , author van der Klis , M. , year 2002 . title A Unified Description of the Timing Features of Accreting X-Ray Binaries . journal volume 572 , pages 392--406 . :10.1086/340290, http://arxiv.org/abs/astro-ph/0202213 arXiv:astro-ph/0202213

    arXiv 2002

  7. [7]

    Correlations in Horizontal Branch Oscillations and Break Components in XTE J1701-462 and GX 17+2

    author Bu , Q.c. , author Chen , L. , author Li , Z.s. , author Qu , J.l. , author Belloni , T.M. , author Zhang , L. , year 2015 . title Correlations in Horizontal Branch Oscillations and Break Components in XTE J1701-462 and GX 17+2 . journal volume 799 , pages 2 . :10.1088/0004-637X/799/1/2, http://arxiv.org/abs/1411.1137 arXiv:1411.1137

    work page Pith review arXiv 2015

  8. [8]

    Missing hard states and regular outbursts: the puzzling case of the black hole candidate 4U 1630-472

    author Capitanio , F. , author Campana , R. , author De Cesare , G. , author Ferrigno , C. , year 2015 . title Missing hard states and regular outbursts: the puzzling case of the black hole candidate 4U 1630-472 . journal volume 450 , pages 3840--3854 . :10.1093/mnras/stv687, http://arxiv.org/abs/1505.04034 arXiv:1505.04034

    work page Pith review arXiv 2015

Show all 62 references
  1. [9]

    , author Belloni , T

    author Casella , P. , author Belloni , T. , author Homan , J. , author Stella , L. , year 2004 . title A study of the low-frequency quasi-periodic oscillations in the X-ray light curves of the black hole candidate <ASTROBJ>XTE J1859+226</ASTROBJ> . journal volume 426 , pages 5...

    2004 arXiv

  2. [10]

    , author Chen , W

    author Cui , W. , author Chen , W. , author Zhang , S.N. , year 2000 . title Evidence for Doppler-shifted Iron Emission Lines in Black Hole Candidate 4U 1630-47 . journal volume 529 , pages 952--960 . :10.1086/308314, http://arxiv.org/abs/astro-ph/9909023 arXiv:astro-ph/9909023

    2000 arXiv

  3. [11]

    , author Belloni , T

    author Dieters , S.W. , author Belloni , T. , author Kuulkers , E. , author Woods , P. , author Cui , W. , author Zhang , S.N. , author Chen , W. , author van der Klis , M. , author van Paradijs , J. , author Swank , J. , author Lewin , W.H.G. , author Kouveliotou , C. , year ...

    arXiv

  4. [12]

    , author Arzoumanian , Z

    author Gendreau , K.C. , author Arzoumanian , Z. , author Adkins , P.W. , author Albert , C.L. , author Anders , J.F. , author Aylward , A.T. , author Baker , C.L. , author Balsamo , E.R. , author Bamford , W.A. , author Benegalrao , S.S. , author Berry , D.L. , author Bhalwan...

    2016

  5. [13]

    , author Belloni , T

    author Homan , J. , author Belloni , T. , year 2005 . title The Evolution of Black Hole States . journal volume 300 , pages 107--117 . :10.1007/s10509-005-1197-4, http://arxiv.org/abs/astro-ph/0412597 arXiv:astro-ph/0412597

    2005 arXiv

  6. [14]

    , author Bright , J

    author Homan , J. , author Bright , J. , author Motta , S.E. , author Altamirano , D. , author Arzoumanian , Z. , author Basak , A. , author Belloni , T.M. , author Cackett , E.M. , author Fender , R. , author Gendreau , K.C. , author Kara , E. , author Pasham , D.R. , author ...

    2020 arXiv

  7. [15]

    , author Qu , J.L

    author Huang , Y. , author Qu , J.L. , author Zhang , S.N. , author Bu , Q.C. , author Chen , Y.P. , author Tao , L. , author Zhang , S. , author Lu , F.J. , author Li , T.P. , author Song , L.M. , author Xu , Y.P. , author Cao , X.L. , author Chen , Y. , author Liu , C.Z. , a...

    2018 arXiv

  8. [16]

    , author Done , C

    author Ingram , A. , author Done , C. , author Fragile , P.C. , year 2009 . title Low-frequency quasi-periodic oscillations spectra and Lense-Thirring precession . journal volume 397 , pages L101--L105 . :10.1111/j.1745-3933.2009.00693.x, http://arxiv.org/abs/0901.1238 arXiv:0901.1238

    2009

  9. [17]

    , author Motta , S.E

    author Ingram , A.R. , author Motta , S.E. , year 2019 . title A review of quasi-periodic oscillations from black hole X-ray binaries: Observation and theory . journal volume 85 , pages 101524 . :10.1016/j.newar.2020.101524, http://arxiv.org/abs/2001.08758 arXiv:2001.08758

    2019

  10. [18]

    , author Maccarone , T.J

    author Kalemci , E. , author Maccarone , T.J. , author Tomsick , J.A. , year 2018 . title A Dust-scattering Halo of 4U 1630-47 Observed with Chandra and Swift: New Constraints on the Source Distance . journal volume 859 , pages 88 . :10.3847/1538-4357/aabcd3, http://arxiv.org/...

    2018 arXiv

  11. [19]

    , author M \'e ndez , M

    author Karpouzas , K. , author M \'e ndez , M. , author Garc \' a , F. , author Zhang , L. , author Altamirano , D. , author Belloni , T. , author Zhang , Y. , year 2021 . title A variable corona for GRS 1915+105 . journal volume 503 , pages 5522--5533 . :10.1093/mnras/stab827...

    2021 arXiv

  12. [20]

    , author Méndez, M

    author Karpouzas, K. , author Méndez, M. , author Ribeiro, E.M. , author Altamirano, D. , author Blaes, O. , author García, F. , year 2020 . title The Comptonizing medium of the neutron star in 4U 1636-53 through its lower kilohertz quasi-periodic oscillations . journal Monthl...

    2020 arXiv

  13. [21]

    , author Walton , D.J

    author King , A.L. , author Walton , D.J. , author Miller , J.M. , author Barret , D. , author Boggs , S.E. , author Christensen , F.E. , author Craig , W.W. , author Fabian , A.C. , author F \"u rst , F. , author Hailey , C.J. , author Harrison , F.A. , author Krivonos , R. ,...

    2014 arXiv

  14. [22]

    , author Jayasurya , K.M

    author Kushwaha , A. , author Jayasurya , K.M. , author Agrawal , V.K. , author Nandi , A. , year 2023 . title IXPE and NICER view of black hole X-ray binary 4U 1630-47: First significant detection of polarized emission in thermal state . journal volume 524 , pages L15--L20 . ...

    2023 arXiv

  15. [23]

    , author Parmar , A.N

    author Kuulkers , E. , author Parmar , A.N. , author Kitamoto , S. , author Cominsky , L.R. , author Sood , R.K. , year 1997 . title Complex outburst behaviour from the black hole candidate 4U1630-47 . journal volume 291 , pages 81--90 . :10.1093/mnras/291.1.81, http://arxiv.o...

    1997 arXiv

  16. [24]

    , author Darbro , W

    author Leahy , D.A. , author Darbro , W. , author Elsner , R.F. , author Weisskopf , M.C. , author Sutherland , P.G. , author Kahn , S. , author Grindlay , J.E. , year 1983 . title On searches for pulsed emission with application to four globular cluster X-ray sources : NGC 18...

    1983 doi

  17. [25]

    , author Ji , L

    author Liu , H. , author Ji , L. , author Bambi , C. , author Jain , P. , author Misra , R. , author Rawat , D. , author Yadav , J.S. , author Zhang , Y. , year 2021 . title Testing Evolution of LFQPOs with Mass Accretion Rate in GRS 1915+105 with Insight-HXMT . journal volume...

    2021 arXiv

  18. [26]

    , author Miller , J.M

    author Ludlam , R.M. , author Miller , J.M. , author Arzoumanian , Z. , author Bult , P.M. , author Cackett , E.M. , author Chakrabarty , D. , author Dauser , T. , author Enoto , T. , author Fabian , A.C. , author Garc \' a , J.A. , author Gendreau , K.C. , author Guillot , S....

    2018 arXiv

  19. [27]

    , author M \'e ndez , M

    author Ma , R. , author M \'e ndez , M. , author Garc \' a , F. , author Sai , N. , author Zhang , L. , author Zhang , Y. , year 2023 . title A variable corona during the transition from type-C to type-B quasi-periodic oscillations in the black hole X-ray binary MAXI J1820+070...

    2023 arXiv

  20. [28]

    , author Tao , L

    author Ma , X. , author Tao , L. , author Zhang , S.N. , author Zhang , L. , author Bu , Q.C. , author Ge , M.Y. , author Chen , Y.P. , author Qu , J.L. , author Zhang , S. , author Lu , F.J. , author Song , L.M. , author Yang , Y.J. , author Yuan , F. , author Cai , C. , auth...

    2021 arXiv

  21. [29]

    , author Inoue , H

    author Mitsuda , K. , author Inoue , H. , author Koyama , K. , author Makishima , K. , author Matsuoka , M. , author Ogawara , Y. , author Shibazaki , N. , author Suzuki , K. , author Tanaka , Y. , author Hirano , T. , year 1984 . title Energy spectra of low-mass binary X-ray ...

    1984

  22. [30]

    , author Mu \ n oz-Darias , T

    author Motta , S. , author Mu \ n oz-Darias , T. , author Casella , P. , author Belloni , T. , author Homan , J. , year 2011 . title Low-frequency oscillations in black holes: a spectral-timing approach to the case of GX 339-4 . journal volume 418 , pages 2292--2307 . :10.1111...

    2011

  23. [31]

    , author Munoz-Darias , T

    author Motta , S.E. , author Munoz-Darias , T. , author Sanna , A. , author Fender , R. , author Belloni , T. , author Stella , L. , year 2014 . title Black hole spin measurements through the relativistic precession model: XTE J1550-564. journal volume 439 , pages L65--L69 . :...

    2014 arXiv

  24. [32]

    , author Ingram , A

    author Nathan , E. , author Ingram , A. , author Homan , J. , author Huppenkothen , D. , author Uttley , P. , author van der Klis , M. , author Motta , S. , author Altamirano , D. , author Middleton , M. , year 2022 . title Phase-resolved spectroscopy of a quasi-periodic oscil...

    2022 arXiv

  25. [33]

    , author Remillard, R.A

    author Neilsen, J. , author Remillard, R.A. , author Lee, J.C. , year 2011 . title The Physics of the ``Heartbeat'' State of GRS 1915+105 . journal volume 737 , pages 69 . :10.1088/0004-637X/737/2/69, http://arxiv.org/abs/1106.0298 arXiv:1106.0298

    2011 arXiv

  26. [34]

    , author Soong , Y

    author Okajima , T. , author Soong , Y. , author Balsamo , E.R. , author Enoto , T. , author Olsen , L. , author Koenecke , R. , author Lozipone , L. , author Kearney , J. , author Fitzsimmons , S. , author Numata , A. , author Kenyon , S.J. , author Arzoumanian , Z. , author ...

    2016

  27. [35]

    , author Bhattacharyya , S

    author Pahari , M. , author Bhattacharyya , S. , author Rao , A.R. , author Bhattacharya , D. , author Vadawale , S.V. , author Dewangan , G.C. , author McHardy , I.M. , author Gandhi , P. , author Corbel , S. , author Schulz , N.S. , author Altamirano , D. , year 2018 . title...

    2018 arXiv

  28. [36]

    , author Angelini , L

    author Parmar , A.N. , author Angelini , L. , author White , N.E. , year 1996 . title Periodic outbursts from the black hole candidate 4U 1630-47. , in: editor Zimmermann , H.U. , editor Tr \"u mper , J. , editor Yorke , H. (Eds.), booktitle Roentgenstrahlung from the Universe...

    1996

  29. [37]

    , year 1986

    author Priedhorsky , W. , year 1986 . title Recurrent Population II X-ray transients similarities to SU UMa cataclysmic variables . journal volume 126 , pages 89--98 . :10.1007/BF00644177

    1986 doi

  30. [38]

    , author Gendreau , K

    author Prigozhin , G. , author Gendreau , K. , author Doty , J.P. , author Foster , R. , author Remillard , R. , author Malonis , A. , author LaMarr , B. , author Vezie , M. , author Egan , M. , author Villasenor , J. , author Arzoumanian , Z. , author Baumgartner , W. , autho...

    2016

  31. [39]

    , author Lu , F.J

    author Qu , J.L. , author Lu , F.J. , author Lu , Y. , author Song , L.M. , author Zhang , S. , author Ding , G.Q. , author Wang , J.M. , year 2010 . title The Energy Dependence of the Centroid Frequency and Phase Lag of the Quasi-periodic Oscillations in GRS 1915+105 . journa...

    2010 arXiv

  32. [40]

    , author Garg , A

    author Rawat , D. , author Garg , A. , author M \'e ndez , M. , year 2023 a. title Detection of X-Ray Polarized Emission and Accretion-disk Winds with IXPE and NICER in the Black Hole X-Ray Binary 4U 1630-47 . journal volume 949 , pages L43 . :10.3847/2041-8213/acd77b, http://...

    2023 arXiv

  33. [41]

    , author M \'e ndez , M

    author Rawat , D. , author M \'e ndez , M. , author Garc \' a , F. , author Altamirano , D. , author Karpouzas , K. , author Zhang , L. , author Alabarta , K. , author Belloni , T.M. , author Jain , P. , author Bellavita , C. , year 2023 b. title The comptonizing medium of the...

    2023 arXiv

  34. [42]

    , author Loewenstein , M

    author Remillard , R.A. , author Loewenstein , M. , author Steiner , J.F. , author Prigozhin , G.Y. , author LaMarr , B. , author Enoto , T. , author Gendreau , K.C. , author Arzoumanian , Z. , author Markwardt , C. , author Basak , A. , author Stevens , A.L. , author Ray , P....

    2022 arXiv

  35. [43]

    , author McClintock , J.E

    author Remillard , R.A. , author McClintock , J.E. , year 2006 . title X-Ray Properties of Black-Hole Binaries . journal volume 44 , pages 49--92 . :10.1146/annurev.astro.44.051905.092532, http://arxiv.org/abs/astro-ph/0606352 arXiv:astro-ph/0606352

    2006 arXiv

  36. [44]

    , author Titarchuk , L

    author Seifina , E. , author Titarchuk , L. , author Shaposhnikov , N. , year 2014 . title Black Hole Mass Determination in the X-Ray Binary 4U 1630-47: Scaling of Spectral and Variability Characteristics . journal volume 789 , pages 57 . :10.1088/0004-637X/789/1/57, http://ar...

    2014 arXiv

  37. [45]

    , author Sunyaev , R.A

    author Shakura , N.I. , author Sunyaev , R.A. , year 1973 . title Black holes in binary systems. Observational appearance. journal volume 24 , pages 337--355

    1973

  38. [46]

    , author Zhang , S

    author Shui , Q.C. , author Zhang , S. , author Chen , Y.P. , author Zhang , S.N. , author Kong , L.D. , author Wang , P.J. , author Ji , L. , author Yin , H.X. , author Qu , J.L. , author Tao , L. , author Ge , M.Y. , author Peng , J.Q. , author Chang , Z. , author Li , J. , ...

    2023 arXiv

  39. [47]

    , author Rao , A.R

    author Sriram , K. , author Rao , A.R. , author Choi , C.S. , year 2013 . title A Spectral Study of the Rapid Transitions of Type-B Quasi-periodic Oscillations in the Black Hole Transient XTE J1859+226 . journal volume 775 , pages 28 . :10.1088/0004-637X/775/1/28, http://arxiv...

    2013 arXiv

  40. [48]

    , author Vietri , M

    author Stella , L. , author Vietri , M. , year 1998 . title Lense-Thirring Precession and Quasi-periodic Oscillations in Low-Mass X-Ray Binaries . journal volume 492 , pages L59--L62 . :10.1086/311075, http://arxiv.org/abs/astro-ph/9709085 arXiv:astro-ph/9709085

    1998 arXiv

  41. [49]

    , author Titarchuk , L.G

    author Sunyaev , R.A. , author Titarchuk , L.G. , year 1980 . title Comptonization of X-Rays in Plasma Clouds - Typical Radiation Spectra . journal volume 86 , pages 121

    1980

  42. [50]

    , author Kaaret , P

    author Tomsick , J.A. , author Kaaret , P. , year 2000 . title X-Ray Spectral and Timing Evolution during the Decay of the 1998 Outburst from the Recurrent X-Ray Transient 4U 1630-47 . journal volume 537 , pages 448--460 . :10.1086/308999, http://arxiv.org/abs/astro-ph/0002084...

    2000 arXiv

  43. [51]

    , author Borozdin , K.N

    author Trudolyubov , S.P. , author Borozdin , K.N. , author Priedhorsky , W.C. , year 2001 . title RXTE observations of 4U 1630-47 during the peak of its 1998 outburst . journal volume 322 , pages 309--320 . :10.1046/j.1365-8711.2001.04073.x, http://arxiv.org/abs/astro-ph/9911...

    2001

  44. [52]

    , year 1989

    author van der Klis , M. , year 1989 . title Fourier techniques in X-ray timing , in: editor \"O gelman , H. , editor van den Heuvel , E.P.J. (Eds.), booktitle Timing Neutron Stars , p. pages 27 . :10.1007/978-94-009-2273-0_3

    1989 doi

  45. [53]

    , year 2004

    author van der Klis , M. , year 2004 . title A review of rapid X-ray variability in X-ray binaries . journal arXiv e-prints , pages astro--ph/0410551 :10.48550/arXiv.astro-ph/0410551, http://arxiv.org/abs/astro-ph/0410551 arXiv:astro-ph/0410551

    2004 doi

  46. [54]

    , author Migliari , S

    author Vignarca , F. , author Migliari , S. , author Belloni , T. , author Psaltis , D. , author van der Klis , M. , year 2003 . title Tracing the power-law component in the energy spectrum of black hole candidates as a function of the QPO frequency . journal volume 397 , page...

    2003 arXiv

  47. [55]

    , author M \'e ndez , M

    author Wang , Y. , author M \'e ndez , M. , year 2016 . title The XMM-Newton spectra of the 2012 outburst of the black hole candidate 4U 1630-47 revisited . journal volume 456 , pages 1579--1586 . :10.1093/mnras/stv2814, http://arxiv.org/abs/1512.00512 arXiv:1512.00512

    2016 arXiv

  48. [56]

    , author Allen , A

    author Wilms , J. , author Allen , A. , author McCray , R. , year 2000 . title On the Absorption of X-Rays in the Interstellar Medium . journal volume 542 , pages 914--924 . :10.1086/317016, http://arxiv.org/abs/astro-ph/0008425 arXiv:astro-ph/0008425

    2000 arXiv

  49. [57]

    , author Zhang , L

    author Yang , Z.x. , author Zhang , L. , author Huang , Y. , author Bu , Q. , author Zhang , Z. , author Liu , H.X. , author Yu , W. , author Wang , P.J. , author Zhao , Q.C. , author Tao , L. , author Qu , J.L. , author Zhang , S. , author Zhang , S.N. , author Song , L. , au...

    2022 arXiv

  50. [58]

    , author Bu , Q.C

    author Yorgancioglu , E.S. , author Bu , Q.C. , author Santangelo , A. , author Tao , L. , author Davis , S.W. , author Vahdat , A. , author Kong , L.D. , author Piraino , S. , author Zhou , M. , author Zhang , S.N. , year 2023 . title Spin measurement of 4U 1543-47 with Insig...

    2023 arXiv

  51. [59]

    , author Altamirano , D

    author Zhang , L. , author Altamirano , D. , author Uttley , P. , author Garc \' a , F. , author M \'e ndez , M. , author Homan , J. , author Steiner , J.F. , author Alabarta , K. , author Buisson , D.J.K. , author Remillard , R.A. , author Gendreau , K.C. , author Arzoumanian...

    2021 arXiv

  52. [60]

    , author M \'e ndez , M

    author Zhang , L. , author M \'e ndez , M. , author Altamirano , D. , author Qu , J. , author Chen , L. , author Karpouzas , K. , author Belloni , T.M. , author Bu , Q. , author Huang , Y. , author Ma , X. , author Tao , L. , author Wang , Y. , year 2020 . title A systematic a...

    2020 arXiv

  53. [61]

    , author M \'e ndez , M

    author Zhang , Y. , author M \'e ndez , M. , author Garc \' a , F. , author Zhang , S.N. , author Karpouzas , K. , author Altamirano , D. , author Belloni , T.M. , author Qu , J. , author Zhang , S. , author Tao , L. , author Zhang , L. , author Huang , Y. , author Kong , L. ,...

    2022 arXiv

  54. [62]

    , author Tao , L

    author Zhao , Q.C. , author Tao , L. , author Li , H.C. , author Zhang , S.N. , author Feng , H. , author Ge , M.Y. , author Ji , L. , author Wang , Y.N. , author Huang , Y. , author Ma , X. , author Zhang , L. , author Qu , J.L. , author Xu , Y.J. , author Zhang , S. , author...

    2024 arXiv

Pith tools

Reviewed August 10, 2026 · model on record in the stance chip above.