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REVIEW 4 major objections 5 minor 34 references

An Elaborate Search for Coherent Pulsations from Intermittent-AMXPs

T0 review · 4 major / 5 minor · reviewed 2026-08-09 · deepseek-v4-flash

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Pith's one-line read A maximum-likelihood re-analysis of RXTE data finds coherent pulsations persisting beyond standard pulse-detection intervals, and yields an orbital period of 8.764 hours for SAX J1748.9-2021.

desk verdict Solid archival candidate list from the Z1^2 scan, but the ML-based smooth-transition and orbital-period claims need null-hypothesis validation before they can be taken as established. read the letter →

arxiv 2502.03947 v1 pith:JSKXLIFI submitted 2025-02-06 astro-ph.HE

Mustafa Turan Sağlam , Can Güngör , Tuğçe Kocabiyik This is my paper · ORCID
classification astro-ph.HE
keywords intermittentaccretingmillisecondX-raypulsarsZ1-squaredstatisticmaximumlikelihoodphasetrackingpulse-on/offtransitionsorbitalperiodRXTE/PCASAXJ1748.9-2021AqlX-1
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 aims to show that the intermittent X-ray pulsations of three accreting millisecond X-ray pulsars -- Aql X-1, HETE J1900.1-2455, and SAX J1748.9-2021 -- persist longer and turn on and off more gradually than standard power-based searches indicate. Using 16 years of RXTE/PCA data, the authors first locate pulse candidates with the $Z_1^2$ (Rayleigh) statistic in 25-second bins, then feed the candidate pulse profiles into a maximum-likelihood phase-tracking search. The ML method recovers coherent pulsations in intervals where $Z_1^2$ shows no significant detection, and the ML-measured pulse-on durations are slightly longer, which the authors interpret as smooth pulse-on/off transitions whose smoothness varies from event to event. For SAX J1748.9-2021, the phase-offset drift measured by ML outside the $Z_1^2$ pulse intervals traces a sinusoid that gives an updated orbital period of $8.764 \pm 0.001$ hours.

What carries the argument

The engine of the analysis is a maximum-likelihood phase-offset estimator: a pulse profile obtained from a $Z_1^2$-detected segment is smoothed and normalized into a probability density over spin phase, and for each 25-second time bin the likelihood of a phase offset is computed from all photon phases, with the resulting offset distribution fitted by a Gaussian to give the most probable phase and its uncertainty. Tracking this offset over time reveals systematic phase drift caused by binary orbital motion even when the $Z_1^2$ power remains below the detection threshold. The $Z_1^2$ scan itself, with 25-second bins shifted by 1 second, supplies both the candidate pulse intervals and the template profiles that make the ML tracking possible.

What would settle it

Apply the same ML phase-tracking procedure to an RXTE/PCA observation of a source with no known pulsations and a similar count rate: if the phase-offset tracks show systematic, orbit-like wanderings comparable to those reported here, the detections could be noise artifacts. For the orbital period, an independent timing solution of SAX J1748.9-2021 from the 2015 XMM-Newton outburst that disagrees with $8.764 \pm 0.001$ hours would refute the updated period.

Watch

Extended reading notes

Core claim

The central discovery is that maximum-likelihood phase tracking, using a normalized pulse profile from a $Z_1^2$-detected segment as a probability density function, recovers coherent pulsations in time intervals where the $Z_1^2$ statistic alone gives no significant detection. For all three intermittent AMXPs, the ML-derived pulse-on durations are systematically longer than the $Z_1^2$-derived ones, and for SAX J1748.9-2021 the ML phase offsets trace a clean sinusoidal pattern across two datasets spanning intervals with no visible $Z_1^2$ power. The authors take these longer durations and coherent phase drifts as evidence that the transitions between pulse-on and pulse-off stages are smooth and can be continuous, with the pulse amplitude fading to undetectable levels rather than switching off sharply. Combining the turn-over points of the two phase-offset sinusoids with the literature cycle count yields an updated orbital period of $8.764 \pm 0.001$ hours for SAX J1748.9-2021.

Load-bearing premise

The pulse profile built from a $Z_1^2$-detected segment is assumed to remain a valid probability density for ML phase estimation in time intervals where $Z_1^2$ gives no significant detection; if the profile, spin frequency, or cycle count is slightly wrong, or if noise produces spurious phase offsets, the inferred smooth transitions and the orbital period are not supported.

Editorial extensions

If this is right

  • Pulse-on intervals for these systems are longer than previously reported, so the standard sharp on/off picture underestimates the time a source spends pulsing.
  • The maximum-likelihood phase-tracking method can be applied to other X-ray timing archives to recover weak pulsations that power-based searches miss.
  • SAX J1748.9-2021's orbital period is refined to $8.764 \pm 0.001$ hours, a fractional improvement over the literature value used for the cycle count.
  • Phase offsets that drift coherently in time can serve as a pulsation diagnostic even when $Z_1^2$ power is below threshold, making ML tracking a complement to power-spectrum searches.
  • The transition between pulse-on and pulse-off stages is smooth and event-dependent rather than a universal sharp switch, so the underlying accretion geometry must vary.

Reading between the lines

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

  • If smooth transitions are real, then the duty cycle of an intermittent AMXP is not an intrinsic source property but depends on detector sensitivity: a more sensitive instrument would catch pulses the current searches classify as off.
  • The same template-based phase tracking could be applied to archival RXTE data of other LMXBs without known pulsations, using any tentative detection as a template to search for coherent phase drift.
  • The correlation between transition type (sharp, smooth, continuous-weak) and X-ray luminosity or spectral state could be tested using the long-term light curves; the paper does not perform that correlation.
  • If the orbital period is independently constrained by future outbursts, the ML phase-tracking technique may provide a way to measure period derivatives or apsidal motion for this source.
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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 / 5 minor

Summary. The paper reports a systematic search for coherent X-ray pulsations from three intermittent accreting millisecond X-ray pulsars (Aql X-1, HETE J1900.1-2455, SAX J1748.9-2021) using all available RXTE/PCA data. A Z_1^2 scan over 25 s intervals with 1 s shifts is used to identify pulse candidates, followed by an RMS smoothness cut and Monte Carlo estimates of chance probabilities. For selected candidates, a maximum likelihood (ML) method is applied to track pulse phase offsets, using the Z_1^2-derived pulse profile as a probability density. The authors claim that the ML phase tracking reveals coherent pulsation persisting beyond the Z_1^2-detected intervals, implying smooth pulse-on/off transitions, and they use the phase-offset evolution in two RXTE observations of SAX J1748.9-2021 to derive an orbital period of 8.764 ± 0.001 hours.

Significance. If fully validated, the paper would provide useful new pulse detections for three intermittent-AMXPs and an interesting constraint on the transition mechanism between pulse-on and pulse-off states. The Z_1^2 search is systematic, covers 16 years of data, and includes Monte Carlo false-alarm estimates for the pulse candidates, which is a strength. However, the additional claims — the smooth transition inferred from ML phase offsets and the revised orbital period of SAX J1748.9-2021 — rest on ML phase estimates in intervals where Z_1^2 gives no significant detection, and no null-hypothesis validation is provided for those phase tracks. As presented, these claims are not yet quantitatively supported, which limits the significance of the paper in its current form.

major comments (4)
  1. [§2.3, Eq. (5); §3, Figs. 7-9] The ML phase-offset estimates are not accompanied by any likelihood-ratio test, false-alarm probability, or noise simulation. Equation (5) yields a best-fit phase offset for any photon realization, so a smoothly evolving or even turnover-containing phase curve can arise from noise or from a fixed frequency error. The paper's central claims — that ML phase offsets persist beyond the Z_1^2 intervals, that transitions are smooth, and that the phase pattern in Fig. 9 reflects orbital motion — depend on interpreting a smooth phase track as coherent pulsation. A concrete test would be to apply the identical ML procedure to simulated non-pulsed data with the same count rates and show that the inferred phase offsets do not produce similarly smooth, turnover-containing curves, or to compute a detection significance for phase coherence against the null hypothesis of constant phase.
  2. [§3, Fig. 9 and the orbital-period derivation] The orbital period of 8.764 ± 0.001 h is derived from two local maxima of the modified phase-offset curves, with the integer cycle count between them taken from the literature period of 8.85 h. The two parabolic segments in the bottom panels of Fig. 9 are fit over only ~0.035-day intervals, and a constant spin-frequency error produces exactly a quadratic phase residual over such a short span. The quoted ±0.001 h precision does not include the uncertainty in the assumed cycle count, and the derived value differs from the 8.85 h literature value by about 0.5 h, which is not addressed. The paper needs to demonstrate that the phase model is consistent across the full data span with the cycle count resolved, and that the derived period is not an artifact of local quadratic fits to a frequency-mismatch residual.
  3. [§2.3, Eq. (5)] The pulse profile used to construct the probability density in Eq. (5) is obtained from a Z_1^2-detected interval and is assumed to remain valid as the probability density for ML phase estimation in neighboring and non-detected intervals. This is an unvalidated assumption. If the profile, spin frequency, or cycle count is slightly wrong, or if the profile evolves between outbursts, the ML phase offsets will be biased, and the inferred smooth transitions and the orbital period will not be supported. The authors should test the robustness of the ML phase estimator with injected signals using the actual pulse profile, including cases with small frequency and profile mismatches.
  4. [§3, smooth-transition inference] The claim that ML pulse-on durations are 'slightly longer' than Z_1^2 durations and hence that transitions are smooth is based on a qualitative comparison of the extent of systematic phase evolution in a few examples (Figs. 7 and 8). No criterion is given for what constitutes a systematic phase change, no uncertainties are reported for the ML pulse-on durations, and the number of cases is small. The paper's conclusion that 'the transition between pulse-on and pulse-off stages are smooth' is load-bearing and requires a quantitative definition of pulse-on duration in the ML phase track, along with a statistical comparison to the Z_1^2 durations. Without this, the smooth-transition claim is not established.
minor comments (5)
  1. [§2.3, Eq. (5)] The quantity 'Prob(ϕoff)' in Eq. (5) is a likelihood, not a probability; it should be called the likelihood function or the joint likelihood, and the normalization should be clarified.
  2. [§2.2, Table 2] The 'chance probability' values in Table 2 are quoted as single-trial probabilities, while the simulations described later in §3 give global false-alarm rates; the relation between these two quantities should be stated explicitly.
  3. [§3, Fig. 9] There are typographical inconsistencies in the figure labels and text: '6035-02-03-00' for the ObsID, 'M method' instead of 'ML method', and 'Diving the time gap' instead of 'Dividing the time gap'.
  4. [§3] The sentence 'we performed the ML scan ~50 days around them' is inconsistent with the time ranges shown in Figs. 7-9, which cover hours rather than days; the scanned time window should be stated precisely.
  5. [§1, Table 1] In Table 1, the column header 'Burst oscillation frequency' is used for the spin frequency of the sources; this is potentially misleading because burst oscillations and coherent pulsations are distinct phenomena, and the notation should be corrected.

Circularity Check

0 steps flagged · score 0.0 of 10

No circular reduction: ML phase offsets are data-dependent and the orbital period is a standard ephemeris refinement; the main gap is statistical validation, not circularity.

full rationale

The derivation chain is not circular. The Z1^2 scan is an independent periodicity test, and the ML step uses the Z1^2-derived pulse profile only as a fixed template; Eq. (5) then yields phase offsets from the actual photon arrival times, so the offsets are data-dependent and not equal to the template by construction. The 'pulse-on duration via ML' and the smooth-transition claim rest on interpreting the time evolution of these offsets, not on the profile itself. The orbital period for SAX J1748.9-2021 is obtained from the time separation of two phase-curve turn-overs divided by an integer cycle count adopted from the literature period, which is a standard ephemeris-refinement step rather than a renaming of the input. No load-bearing result is justified by a self-citation; the cited Güngör et al. (2017) appears only as a physical interpretation of smooth transitions. The main weakness is statistical rather than circular: the ML phase estimator returns a best-fit phase for any data, and the paper reports no false-alarm probability or noise-only simulations for the phase track, so the smooth-transition and 8.764 h claims are less secure than presented. That is a calibration/validation gap, not a circular reduction.

Assumptions & free parameters 4 free parameters · 4 assumptions · 0 invented entities

The central new claims are not self-contained: the ML phase tracking assumes a pulse profile obtained from Z1^2 detections, and the orbital period uses a literature period to count cycles. The Z1^2 candidate search is more independent, but its thresholds and RMS limits are partly calibrated to known detections.

free parameters (4)
  • Common Z1^2 power threshold = 25.0
    Semi-arbitrary threshold; corresponds to 5.6 sigma for Aql X-1, 3.6 sigma for HETE J1900.1-2455, and 3.7 sigma for SAX J1748.9-2021. All Z1^2 candidates depend on this.
  • RMS pulse-profile smoothness limit = 1e-2
    Second elimination criterion calibrated using pulse segments already known from the literature; affects which candidates pass.
  • ML phase step and profile bin width = 1e-4
    Phase bin width used to build the normalized pulse profile for the ML probability density function.
  • Frequency search ranges and step = 550.0-550.5, 336.0-338.0, 441.0-443.0 Hz with 1e-4 Hz step
    Search ranges and step chosen around literature spin frequencies to cover orbital Doppler; may exclude pulses outside these ranges.
assumptions (4)
  • ad hoc to paper The pulse profile derived from a Z1^2-detected interval remains valid as the probability density for ML phase estimation in neighboring and non-detected intervals.
    Section 2.3(iv) uses the normalized profile from a detected segment to compute Prob(phi_off) for all photons in the scanned interval, including intervals where Z1^2 shows no pulsation (Section 3, Fig. 9).
  • domain assumption Spin frequency is constant over each scanned interval and orbital motion is sufficiently covered by scanning a narrow frequency range around the literature value.
    Section 2.2 sets frequency ranges 0.5-2 Hz wide with step 1e-4 Hz; no binary demodulation or frequency derivative is applied.
  • domain assumption The ML phase-offset probability distribution is Gaussian, so FWHM gives a valid uncertainty.
    Section 2.3(v) models the probability distribution with a Gaussian and uses FWHM as the error; no validation for short Poisson-limited segments.
  • domain assumption The literature orbital period is accurate enough to give an unambiguous integer cycle count between two phase maxima.
    Section 3 uses the literature orbital period to obtain the cycle count before updating the period; an off-by-one cycle changes the period by roughly one sixth.

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Cite this review

Pith. "Pith review of An Elaborate Search for Coherent Pulsations from Intermittent-AMXPs." pith.science (2026). https://pith.science/paper/JSKXLIFI

@misc{pith2026250203947,
  author       = {Pith},
  title        = {Pith review of: An Elaborate Search for Coherent Pulsations from Intermittent-AMXPs},
  year         = {2026},
  howpublished = {\url{https://pith.science/paper/JSKXLIFI}},
  note         = {Machine review of arXiv:2502.03947}
}
abstract

We present a detailed systematic pulse search for three Intermittent-Accreting Millisecond X-ray Pulsars (Intermittent-AMXPs), HETE J1900.1-2455, SAX J1748.9-2021 & Aql X-1, via Z$_1^2$ and maximum likelihood (ML) techniques by using 16 years data of Rossi X-ray Timing Explorer/Proportional Counter Array (RXTE/PCA) in the energy range of 3.0 - 13.0 keV. We first performed a pulse scan using the Z$_1^2$ technique in millisecond sensitivities for every 25 s time interval with 1 s shifts to cover all data set around the detected frequencies given in the literature. We tracked the Z$_1^2$ power over time and flagged the time intervals exceeding defined threshold levels for each source as \textit{pulse candidates}. The detected pulse list throughout our scan has new discoveries while covering the pulsed regions presented in the literature. For a deeper search, using the pulses obtained from the Z$_1^2$ method as a probability density function as an input parameter, we re-scanned the time intervals centered on the detected pulse via ML. The detected pulse-on duration via ML is slightly longer than the one via Z$_1^2$ method. This phenomenon allows us to argue for the existence of the smooth transition between pulse-on and pulse-off stages. For SAX J1748.9-2021, we also obtained orbital period by using the systematic pulse arrival phase patterns throughput of ML to be 8.76 hours.

Figures

Figures reproduced from arXiv: 2502.03947 by the authors.

Figure 1
Figure 1. The long term light curve of Aql X-1 via ASM daily data with the times of [PITH_FULL_IMAGE:figures/full_fig_p003_1.png] view at source ↗
Figure 2
Figure 2. Same as [PITH_FULL_IMAGE:figures/full_fig_p004_2.png] view at source ↗
Figure 3
Figure 3. Same as [PITH_FULL_IMAGE:figures/full_fig_p005_3.png] view at source ↗
Figures from the paper (6 more)
Figure 4
Figure 4. Figure 4: The power spectrum of last 150 s of the data with the ObsID of 30188-03-05-00 of of [PITH_FULL_IMAGE:figures/full_fig_p007_4.png]
Figure 5
Figure 5. Figure 5: Dynamic power spectra for selected pulse regions with high power values for Aql X [PITH_FULL_IMAGE:figures/full_fig_p009_5.png]
Figure 6
Figure 6. Figure 6: Phase probability distributions of the pulse profile obtained for the strongest pulse region [PITH_FULL_IMAGE:figures/full_fig_p013_6.png]
Figure 7
Figure 7. Figure 7: The dynamic power spectra of the strongest pulse regions for Aql X-1 (ObsID: 30188-03- [PITH_FULL_IMAGE:figures/full_fig_p014_7.png]
Figure 8
Figure 8. Figure 8: Same as [PITH_FULL_IMAGE:figures/full_fig_p017_8.png]
Figure 9
Figure 9. Figure 9: The dynamic power spectra (upper panels), the time evolution of the phase shifts obtained via [PITH_FULL_IMAGE:figures/full_fig_p018_9.png]

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Works this paper leans on

34 extracted references · 27 canonical work pages

  1. [1]

    A new class of radio pulsars

    Alpar, M.A., Cheng, A.F., Ruderman, M.A., Shaham, J., 1982. A new class of radio pulsars. Nature 300, 728–730. doi:10.1038/300728a0

    doi:10.1038/300728a0 1982

  2. [2]

    Is GX5 - 1 a millisecond pulsar? Nature 316, 239–241

    Alpar, M.A., Shaham, J., 1985. Is GX5 - 1 a millisecond pulsar? Nature 316, 239–241. doi:10.1038/316239a0

    doi:10.1038/316239a0 1985

  3. [3]

    Intermittent millisecond X-ray pulsations from the neutron-star X-ray transient SAX J1748.9-2021 in the globular cluster NGC 6440

    Altamirano, D., Casella, P., Patruno, A., Wijnands, R., van der Klis, M., 2008. In- termittent Millisecond X-Ray Pulsations from the Neutron Star X-Ray Transient SAX J1748.9-2021 in the Globular Cluster NGC 6440. ApJ 674, L45. doi:10.1086/528983, arXiv:0708.1316

    work page Pith review arXiv 2008

  4. [4]

    Search for Intermittent X-ray Pulsations from Neutron Stars in Low Mass X-ray Binaries

    Bahar, Y.E., Chakraborty, M., Göˇ güş, E., 2021. SearchforintermittentX-raypulsations from neutron stars in low-mass X-ray binaries. Publ. Astron. Soc. Australia 38, e011. doi:10.1017/pasa.2021.6, arXiv:2102.03132

    work page Pith review arXiv 2021

  5. [5]

    Effect of an Electron Scattering Cloud on X-Ray Oscillations Produced by Beaming

    Brainerd, J., Lamb, F.K., 1987. Effect of an Electron Scattering Cloud on X-Ray Oscillations Produced by Beaming. ApJ 317, L33. doi:10.1086/184908

    work page doi:10.1086/184908 1987

  6. [6]

    20 Search for pulsed γ-ray emission from radio pulsars in the COS-B data

    Buccheri, R., Bennett, K., Bignami, G.F., Bloemen, J.B.G.M., Boriakoff, V., Car- aveo, P.A., Hermsen, W., Kanbach, G., Manchester, R.N., Masnou, J.L., Mayer- Hasselwander, H.A., Özel, M.E., Paul, J.A., Sacco, B., Scarsi, L., Strong, A.W., 1983. 20 Search for pulsed γ-ray emission from radio pulsars in the COS-B data. A&A 128, 245–251

    work page 1983

  7. [7]

    On Low Mass X-ray Binaries and Millisecond Pulsar

    Burderi, L., DiSalvo, T., 2013. OnlowmassX-raybinariesandmillisecondpulsar. Mem. Soc. Astron. Italiana 84, 117. doi:10.48550/arXiv.1310.1283, arXiv:1310.1283

    work page Pith review arXiv doi:10.48550/arxiv.1310.1283 2013

  8. [8]

    Discovery of Coherent Millisecond X-Ray Pulsations in Aquila X-1

    Casella, P., Altamirano, D., Patruno, A., Wijnands, R., van der Klis, M., 2008. Discovery of Coherent Millisecond X-Ray Pulsations in Aquila X-1. ApJ 674, L41. doi:10.1086/528982, arXiv:0708.1110

    arXiv 2008

Show all 34 references
  1. [9]

    Accreting Binaries; Nature, formation, and evolution

    Chaty, S., 2022. Accreting Binaries; Nature, formation, and evolution. doi:10.1088/ 2514-3433/ac595f

    2022

  2. [10]

    Discovery of a 19-hour period in Aquila X-1

    Chevalier, C., Ilovaisky, S.A., 1991. Discovery of a 19-hour period in Aquila X-1. A&A 251, L11

    1991

  3. [11]

    Magnetic Screening in Accreting Neutron Stars

    Cumming, A., Zweibel, E., Bildsten, L., 2001. Magnetic Screening in Accreting Neutron Stars. ApJ 557, 958–966. doi:10.1086/321658, arXiv:astro-ph/0102178

    2001 arXiv

  4. [12]

    A catalogue of low-mass X-ray binaries in the Galaxy: from the INTEGRAL to the Gaia era

    Fortin, F., Kalsi, A., García, F., Chaty, S., 2024. A catalogue of low-mass X-ray binaries in the Galaxy: from the INTEGRAL to the Gaia era. arXiv e-prints , arXiv:2401.11931arXiv:2401.11931

    2024 arXiv

  5. [13]

    Ther- monuclear (Type I) X-Ray Bursts Observed by the Rossi X-Ray Timing Explorer

    Galloway, D.K., Muno, M.P., Hartman, J.M., Psaltis, D., Chakrabarty, D., 2008. Ther- monuclear (Type I) X-Ray Bursts Observed by the Rossi X-Ray Timing Explorer. ApJS 179, 360–422. doi:10.1086/592044, arXiv:astro-ph/0608259

    2008 arXiv

  6. [14]

    Discovery of 442 Hz Pulsations from an X-Ray Source in the Globular Cluster NGC 6440

    Gavriil, F.P., Strohmayer, T.E., Swank, J.H., Markwardt, C.B., 2007. Discovery of 442 Hz Pulsations from an X-Ray Source in the Globular Cluster NGC 6440. ApJ 669, L29–L32. doi:10.1086/523758, arXiv:0708.0829

    2007 arXiv

  7. [15]

    Is the Lack of Pulsations in Low-Mass X- Ray Binaries due to Comptonizing Coronae? ApJ 659, 580–584

    Göˇ güş, E., Alpar, M.A., Gilfanov, M., 2007. Is the Lack of Pulsations in Low-Mass X- Ray Binaries due to Comptonizing Coronae? ApJ 659, 580–584. doi:10.1086/512028, arXiv:astro-ph/0612680

    2007 arXiv

  8. [16]

    Partial Accretion in the Propeller Stage of Low-mass X-Ray Binary Aql X-1

    Güngör, C., Ekşi, K.Y., Göğüş, E., Güver, T., 2017. Partial Accretion in the Propeller Stage of Low-mass X-Ray Binary Aql X-1. ApJ 848, 13. doi: 10.3847/1538-4357/ aa8b76, arXiv:1709.02378

    2017 arXiv

  9. [17]

    A new X-ray outburst in the globular cluster NGC 6440: SAX J1748.9-2021

    in ’t Zand, J.J.M., Verbunt, F., Strohmayer, T.E., Bazzano, A., Cocchi, M., Heise, J., van Kerkwijk, M.H., Muller, J.M., Natalucci, L., Smith, M.J.S., Ubertini, P., 1999. A new X-ray outburst in the globular cluster NGC 6440: SAX J1748.9-2021. A&A 345, 100–108. doi:10.48550/ar...

    1999 doi arXiv

  10. [18]

    The distances to galactic low-mass x-ray binaries: consequences for black hole luminosities and kicks

    Jonker, P.G., Nelemans, G., 2004. The distances to galactic low-mass x-ray binaries: consequences for black hole luminosities and kicks. Monthly Notices of the Royal As- tronomical Society 354, 355–366

    2004

  11. [19]

    Discovery of the Mil- lisecond X-Ray Pulsar HETE J1900.1-2455

    Kaaret, P., Morgan, E.H., Vanderspek, R., Tomsick, J.A., 2006. Discovery of the Mil- lisecond X-Ray Pulsar HETE J1900.1-2455. ApJ 638, 963–967. doi:10.1086/498886, arXiv:astro-ph/0510483. 21

    2006 arXiv

  12. [20]

    Discovery of x-ray bursts from aquila x-1

    Koyama, K., Inoue, H., Makishima, K., Matsuoka, M., Murakami, T., Oda, M., Os- gawara, Y., Ohashi, T., Shibazaki, N., Tanaka, Y., et al., 1981. Discovery of x-ray bursts from aquila x-1. The Astrophysical Journal 247, L27–L29

    1981

  13. [21]

    Accretion to magnetized stars through the Rayleigh-Taylor instability: global 3D simulations

    Kulkarni, A.K., Romanova, M.M., 2008. Accretion to magnetized stars through the Rayleigh-Taylor instability: global 3D simulations. MNRAS 386, 673–687. doi: 10. 1111/j.1365-2966.2008.13094.x, arXiv:0802.1759

    2008

  14. [22]

    TemporaleffectsofelectronscatteringontheoscillationsofanX-ray source

    Kylafis, N.D., 1988. TemporaleffectsofelectronscatteringontheoscillationsofanX-ray source. Advances in Space Research 8, 455–458. doi:10.1016/0273-1177(88)90442-5

    1988 doi

  15. [23]

    A Model for the Waveform Behavior of Accreting Mil- lisecond X-Ray Pulsars: Nearly Aligned Magnetic Fields and Moving Emission Regions

    Lamb, F.K., Boutloukos, S., Van Wassenhove, S., Chamberlain, R.T., Lo, K.H., Clare, A., Yu, W., Miller, M.C., 2009a. A Model for the Waveform Behavior of Accreting Mil- lisecond X-Ray Pulsars: Nearly Aligned Magnetic Fields and Moving Emission Regions. ApJ 706, 417–435. doi:10...

    arXiv

  16. [24]

    Origin of Intermittent Accretion-Powered X-ray Oscillations in Neutron Stars with Millisecond Spin Periods

    Lamb, F.K., Boutloukos, S., Van Wassenhove, S., Chamberlain, R.T., Lo, K.H., Miller, M.C., 2009b. Origin of Intermittent Accretion-Powered X-ray Oscillations in Neutron Stars with Millisecond Spin Periods. ApJ 705, L36–L39. doi:10.1088/0004-637X/705/ 1/L36, arXiv:0809.4016

    arXiv

  17. [25]

    X-ray and Radio Timing of the Pulsar in 3C 58

    Livingstone, M.A., Ransom, S.M., Camilo, F., Kaspi, V.M., Lyne, A.G., Kramer, M., Stairs, I.H., 2009. X-ray and Radio Timing of the Pulsar in 3C 58. ApJ 706, 1163–1173. doi:10.1088/0004-637X/706/2/1163, arXiv:0901.2119

    2009 arXiv

  18. [26]

    The donor of Aquila X-1 revealed by high-angular resolution near-infrared spectroscopy

    Mata Sánchez, D., Muñoz-Darias, T., Casares, J., Jiménez-Ibarra, F., 2016. The donor of Aquila X-1 revealed by high-angular resolution near-infrared spectroscopy. Monthly Notices of the Royal Astronomical Society: Letters 464, L41–L45. URL:https://doi. org/10.1093/mnrasl/slw17...

    2016 doi

  19. [27]

    Gravitational Light Bending near Neutron Stars

    Meszaros, P., Riffert, H., 1988. Gravitational Light Bending near Neutron Stars. II. Accreting Pulsar Spectra as a Function of Phase. ApJ 327, 712. doi:10.1086/166227

    1988 doi

  20. [28]

    The low galactic latitude metal-rich globular cluster NGC 6440

    Ortolani, S., Barbuy, B., Bica, E., 1994. The low galactic latitude metal-rich globular cluster NGC 6440. A&AS 108, 653–659

    1994

  21. [29]

    Phase-Coherent Timing of the Accreting Millisecond Pulsar SAX J1748.9-

    Patruno, A., Altamirano, D., Hessels, J.W.T., Casella, P., Wijnands, R., van der Klis, M., 2009. Phase-Coherent Timing of the Accreting Millisecond Pulsar SAX J1748.9-

    2009

  22. [30]

    UnstableDiskAccretiononto Magnetized Stars: First Global Three-dimensional Magnetohydrodynamic Simulations

    Romanova, M.M., Kulkarni, A.K., Lovelace, R.V.E., 2008. UnstableDiskAccretiononto Magnetized Stars: First Global Three-dimensional Magnetohydrodynamic Simulations. ApJ 673, L171. doi:10.1086/527298, arXiv:0711.0418

    2008 arXiv

  23. [31]

    Timing of the accreting millisecond pulsar SAX J1748.9-2021 during its 2015 outburst

    Sanna, A., Burderi, L., Riggio, A., Pintore, F., Di Salvo, T., Gambino, A.F., Iaria, R., Matranga, M., Scarano, F., 2016. Timing of the accreting millisecond pulsar SAX J1748.9-2021 during its 2015 outburst. MNRAS 459, 1340–1349. doi:10.1093/mnras/ stw740, arXiv:1603.08757. 22

    2016 arXiv

  24. [32]

    On the X-Ray Variability of Magnetar 1RXS J170849.0-400910

    Scholz, P., Archibald, R.F., Kaspi, V.M., Ng, C.Y., Beardmore, A.P., Gehrels, N., Kennea, J.A., 2014. On the X-Ray Variability of Magnetar 1RXS J170849.0-400910. ApJ 783, 99. doi:10.1088/0004-637X/783/2/99, arXiv:1401.5000

    2014 arXiv

  25. [33]

    Possible new X-ray burst source detected by HETE

    Vanderspek, R., Morgan, E., Crew, G., Graziani, C., Suzuki, M., 2005. Possible new X-ray burst source detected by HETE. The Astronomer’s Telegram 516, 1. 23

    2005

  26. [2021]

    doi:10.1088/0004-637X/690/2/1856, arXiv:0801.1031

    ApJ 690, 1856–1865. doi:10.1088/0004-637X/690/2/1856, arXiv:0801.1031

    arXiv

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Reviewed August 9, 2026 · model on record in the stance chip above.