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REVIEW 2 major objections 6 minor 123 references

A simple time-varying spherical solar-wind model is enough to protect nanohertz gravitational-wave results at typical PTA frequencies once interstellar DM is also modelled.

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2026-07-13 01:04 UTC pith:7YQJE7BP

load-bearing objection Solid empirical result: IPS-UCSD cubes bias real MPTA CRN/HD recovery, while the usual spherical SW model plus DMGP still recovers injected GWB correlations. the 2 major comments →

arxiv 2607.09004 v1 pith:7YQJE7BP submitted 2026-07-10 astro-ph.HE astro-ph.SRgr-qc

Interplanetary scintillation-informed heliospheric modelling for the MeerKAT Pulsar Timing Array 4.5 yr dataset

Saurav Mishra , Daniel J. Reardon , Andrew Zic , Matthew Bailes , John Morgan , Atharva D. Kulkarni , Matthew T. Miles , Ryan M. Shannon
show 4 more authors
Caterina Tiburzi Mark Cheung Michael Kramer Ruoyao Ni
This is my paper
classification astro-ph.HE astro-ph.SRgr-qc
keywords pulsar timing arraysheliospheresolar windinterplanetary scintillationdispersion measuregravitational wave backgroundMeerKAT
verification ladder T0 review T1 audit T2 compute T3 formal T4 reserved

The pith

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

Heliospheric plasma delays the arrival of pulsar pulses and can leak into searches for a nanohertz gravitational-wave background. This paper tests whether a three-dimensional, time-dependent density model built from interplanetary scintillation (the IPS-UCSD reconstruction) can replace the simple time-varying spherical model that pulsar timing arrays currently use. Applied to the 4.5-year MeerKAT PTA data set, the IPS model does not remove the delays cleanly; residual high-frequency structure contaminates the common red noise and biases the recovered gravitational-wave parameters. Simulations that inject the same IPS densities as “truth” show that the spherical model also fails to capture the full spatial complexity. Yet when interstellar dispersion-measure variations are fitted jointly, the spherical-model errors are largely absorbed by the DM process, leaving the gravitational-wave spectrum and spatial correlations intact. The practical conclusion is that the existing spherical prescription is already adequate at L-band frequencies, provided the rest of the noise model is complete. The most precisely timed pulsars may later help refine the three-dimensional heliospheric maps themselves.

Core claim

Direct application of the IPS-UCSD three-dimensional heliosphere reconstruction to the MeerKAT PTA 4.5-year data set fails to correct heliosphere-induced timing delays and biases the recovered common-red-noise / gravitational-wave parameters. When the same reconstruction is treated as a realistic injected signal, the conventional time-varying spherical model also leaves residuals; those residuals are largely absorbed by the interstellar DM Gaussian process, so that the injected gravitational-wave spectrum and Hellings–Downs correlations remain recoverable. Hence a time-varying spherical model is sufficient at typical PTA radio frequencies once other signal components are modelled.

What carries the argument

The IPS-UCSD three-dimensional tomography of heliospheric electron density, converted to line-of-sight dispersion measure (SWIPS) and compared with the standard deterministic-plus-Gaussian-process spherical model (SWmean + SWGP) inside the enterprise Bayesian noise analysis.

Load-bearing premise

That the cleaned and hybrid-corrected IPS-UCSD density cubes are a faithful enough stand-in for the true heliosphere both when subtracted from real data and when injected as “truth” into simulations.

What would settle it

A joint analysis in which an independent, higher-fidelity heliospheric density map (or a longer, lower-frequency PTA data set) is substituted for IPS-UCSD; if the spherical-plus-DM model then leaves residual common power that biases the Hellings–Downs amplitude, the sufficiency claim fails.

Watch this falsifier — get emailed when new claim-graph text bears on it.

Editorial analysis

A structured set of objections, weighed in public.

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

Referee Report

2 major / 6 minor

Summary. The paper tests whether IPS-UCSD 3-D heliospheric density reconstructions can replace or improve the standard time-varying spherically symmetric solar-wind model (SWmean+SWGP) in PTA analyses. Applied to the MeerKAT PTA 4.5 yr DR2, direct use of cleaned IPS-derived DM delays (SWIPS) biases recovered interstellar DM spectral indices and common-red-noise parameters and reduces Hellings–Downs S/N; adding a residual SWGP component restores consistency with the spherical model. Controlled simulations that inject the IPS cubes as a plausible complex heliosphere show that SWmean+SWGP plus a DM Gaussian process still recovers the injected GWB correlation and spectral index, even though the spherical model does not capture the full IPS structure. The authors conclude that a time-varying spherical model is sufficient for GWB recovery at L-band frequencies when other chromatic processes are modelled, and that high-precision pulsars may later help improve data-driven heliosphere models.

Significance. The result is of direct practical importance for ongoing PTA GWB searches: it justifies continued use of the computationally simple SWmean+SWGP model at typical PTA frequencies and quantifies the residual risk from heliospheric misspecification. Strengths include a transparent three-model comparison on real MPTA DR2 data (posteriors, time-domain realisations, optimal-statistic ORFs), three carefully designed injection simulations that isolate heliospheric leakage, and an explicit free-spectrum test of the power-law assumption for n1AU. The work also opens a concrete path for using the best-timed MSPs as independent constraints on IPS tomography.

major comments (2)
  1. Section 2.3: the hybrid correction that supplies DM beyond 3 AU is constructed from the maximum-likelihood SWmean+SWGP realisation of the same MPTA DR2 data set. This introduces a mild circular dependence when SWIPS is later compared with SWmean+SWGP on real data (Figs. 4–6). The simulations inject the IPS map independently and therefore remain clean, but the real-data claim that SWIPS alone is inadequate would be stronger if the outer-heliosphere patch were derived from an independent density model (or if a pure IPS-only integration truncated at 3 AU were shown as a control).
  2. Section 2.3 and Fig. 3: the outlier rejection thresholds (error bar >15 imes the global std and DMIPS >3 imes the SWmean+SWGP prediction) are purely empirical. A short sensitivity test—re-running the CRN search after modest changes to these cuts—would confirm that the reported bias in CRN spectral index and HD S/N is not an artefact of the particular cleaning choices.
minor comments (6)
  1. Abstract and §4: the statement that the spherical model “also fails to fully capture” IPS-like variations is accurate for the free-spectrum test (Fig. 9) but can be misread as contradicting the sufficiency claim; a clarifying clause that the residual is absorbed by DMGP would help.
  2. Fig. 2 caption: “threcliptic” and “SUn’s” are typos; also clarify that the colour bar is normalised electron density.
  3. Eq. (3) and surrounding text: rEarth is written without a space or subscript consistency; a uniform notation for Earth–Sun distance would improve readability.
  4. Section 2.4: the choice of 100 ns white-noise floor and the fixed γDMGP=8/3 are reasonable, but a one-sentence justification that these values do not drive the recovered GWB correlation would be useful.
  5. Affiliation 10: “Imperial Colledge London” is misspelled.
  6. Data-availability statement: the promise that the IPS-derived DM series and simulation seeds will be shared on request is welcome; depositing them with the AAO Data Central release would further aid reproducibility.

Circularity Check

1 steps flagged

Mild construction dependence in the SWIPS outer-heliosphere patch (uses MPTA SWmean+SWGP ML realisation) does not force the central sufficiency claim; simulations inject IPS independently.

specific steps
  1. fitted input called prediction [Section 2.3, steps (i)–(ii) of the beyond-3 AU correction for DMIPS,final]
    "Estimate a time-varying spherically symmetric heliosphere from the maximum likelihood realisation of “SWmean+SWGP” from the MPTA DR2 noise analysis. Compute the excess DM from 3AU to the pulsar as the difference between this spherically symmetric model and the DM obtained by integrating that same model only to 3AU. Add that excess DM to the DMIPS to form an updated DMIPS, known as DMIPS,updated. ... from the updated DMIPS,updated, compute the time-varying n1AU e using eq. 3. Smooth this n1AU e with a spline model ... Add this smoothed excess DM to the original DMIPS, known as DMIPS,final."

    The outer-heliosphere contribution that completes SWIPS is constructed from the maximum-likelihood SWmean+SWGP realisation of the identical MPTA DR2 data set that is later used as the comparison baseline. Consequently, when SWIPS is compared with SWmean+SWGP on real data, part of the outer spherical component is shared by construction. The dependence is mild (inner 3 AU remains pure IPS; a subsequent spline smooths long-term structure) and does not affect the injection simulations, but it is a fitted-input dependence that slightly softens the independence of the real-data SWIPS vs SWmean+SWGP contrast.

full rationale

The paper's central claim—that a time-varying spherically-symmetric model (SWmean+SWGP) plus interstellar DMGP is sufficient to protect recovered GW parameters at L-band, while direct use of cleaned IPS-UCSD cubes biases CRN/HD—is supported by independent real-data posteriors (Figs. 4–6), time-domain realisations (Fig. 5), and controlled injection simulations (Figs. 7–9) that treat the IPS cubes as an external plausible realisation. The only circular step is the two-step beyond-3 AU correction for SWIPS, which re-uses the maximum-likelihood SWmean+SWGP realisation of the same MPTA DR2 data set to supply the outer spherical excess; this creates a mild dependence when SWIPS is later compared with SWmean+SWGP on real data. That dependence is confined to an outer-heliosphere patch, is partially mitigated by subsequent spline smoothing of n1AU, and does not enter the injection simulations. No equation reduces by construction to a fitted parameter that is then claimed as a prediction, and no uniqueness theorem or load-bearing self-citation forces the result. Score 2 reflects one minor, acknowledged construction dependence that does not undercut the main sufficiency conclusion.

Axiom & Free-Parameter Ledger

4 free parameters · 4 axioms · 0 invented entities

The central sufficiency claim rests on standard PTA noise-modelling machinery, the empirical construction of the SWIPS product, and the assumption that the cleaned IPS-UCSD cubes are a realistic proxy for the true heliosphere. No new physical entities are postulated; free parameters are the usual noise amplitudes plus a handful of ad-hoc cleaning thresholds.

free parameters (4)
  • outlier rejection thresholds (15× error-bar std and 3× SWmean+SWGP prediction)
    Chosen empirically to retain bulk of DM_IPS while removing extremes; directly control which IPS epochs enter the SWIPS model used for both real-data and simulation tests.
  • n1AU_e mean and power-law amplitude/spectral index for SWGP
    Fitted free parameters of the spherical solar-wind model; their posterior comparison across models is part of the evidence for sufficiency.
  • DMGP amplitude (drawn from MPTA DR2 distribution) and fixed gamma=8/3
    Controls how much residual heliospheric power can be absorbed by the interstellar DM process in the simulations that underwrite the sufficiency claim.
  • number of Fourier components for free-spectrum SWGP (10/30/100)
    Ad-hoc choice that changes the recovered high-frequency power and white-noise parameters for low-ELAT pulsars.
axioms (4)
  • domain assumption Interstellar DM variations follow a power-law spectrum with Kolmogorov index 8/3 and are independent across pulsars.
    Standard PTA assumption used both for real-data modelling and for injecting DMGP in Simulation 2; if wrong, the absorption of heliospheric residuals into DMGP would be mis-estimated.
  • ad hoc to paper The IPS-UCSD 3-D tomography (after cleaning) is a sufficiently realistic realisation of the true time-varying heliosphere for injection tests.
    Explicitly stated in Section 2.4; the entire simulation campaign and the claim that the spherical model “fails to fully capture” the IPS map rest on this premise.
  • ad hoc to paper Heliospheric density beyond 3 AU can be adequately approximated by a time-varying spherical model whose n1AU is taken from the IPS cubes themselves.
    Two-step hybrid correction of Section 2.3; without it the SWIPS product would contain artificial annual power.
  • domain assumption Gaussian-process Fourier-basis modelling with power-law PSDs is an adequate description of all stochastic processes (RN, DM, SW, GWB).
    Standard enterprise/PTA framework used throughout; free-spectrum results later show the SW power-law is imperfect, yet the paper still relies on it for the main analyses.

pith-pipeline@v1.1.0-grok45 · 28037 in / 3232 out tokens · 39610 ms · 2026-07-13T01:04:17.603097+00:00 · methodology

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Heliospheric density variations impart delays on pulse times of arrivals from millisecond pulsars. Improper modelling of these variations may affect gravitational wave detection and characterisation by pulsar timing arrays (PTAs). Currently, PTAs typically employ a time-varying, spherically symmetric heliosphere model, which does not capture the full spatial and temporal complexity of the heliosphere. Instead, we investigate whether a three-dimensional, time-dependent model of the inner heliosphere from interplanetary scintillation (IPS) measurements - the IPS-UCSD model - can be employed to mitigate the solar wind in PTA analyses. We applied the IPS-UCSD model to the MeerKAT PTA 4.5-year dataset to assess whether it could correct for heliospheric density variations, and the impact on GW sensitivity compared to a spherically-symmetric model. We find that the model does not accurately correct for heliosphere-induced timing distortions, leading to bias in recovered GW parameters. Using simulations, we show that the spherically symmetric heliosphere model also fails to fully capture heliospheric density variations like those in the IPS-UCSD model. However, if interstellar dispersion measure (DM) variations are also modelled, then the heliospheric model errors are partially absorbed by DM variations, reducing contamination of the GW signal. Therefore we find that a time-varying spherically symmetric model is sufficient to mitigate the effect of heliospheric time delays on recovered GW results at typical PTA radio frequencies, provided other signal components are also modelled. We propose that the most precisely timed pulsars may be used to improve data-driven heliospheric density models in the future.

Figures

Figures reproduced from arXiv: 2607.09004 by Andrew Zic, Atharva D. Kulkarni, Caterina Tiburzi, Daniel J. Reardon, John Morgan, Mark Cheung, Matthew Bailes, Matthew T. Miles, Michael Kramer, Ruoyao Ni, Ryan M. Shannon, Saurav Mishra.

Figure 1
Figure 1. Figure 1: DM measurements from PSR J1909−3744 using MeerKAT L-band observations. The grey regions show when the pulsar is within 40 degrees of the Sun. There are annual variations in the DM, e.g. clear DM enhancements around MJDs 58850, 59200, 59600, and 59950, which coincide with epochs of increased solar activity and small Sun-pulsar angular separations. At these times the change in the DM are of the order of 10−4… view at source ↗
Figure 2
Figure 2. Figure 2: Two different cuts through volumetric density reconstructions at two different epochs. The upper plots and lower plots are separated by 2 days. The left plots show approximately ecliptic plane cut of the heliosphere (thr ecliptic pole and the SUn’s rotational pole differe by 7◦ Seidelmann et al. (2007)) with longitude values in degrees, the right plots represent the perpendicular cut of the heliosphere wit… view at source ↗
Figure 3
Figure 3. Figure 3: Predicted heliospheric DM using the IPS-UCSD 3D tomography model for the PSR J1909−3744; Removal of outliers from IPS data and replacement of outliers by interpolating the good IPS data points in the density domain using spline interpolation. The x-axis shows MJD, the left y-axis shows DM. Orange and red points represent good and bad IPS-derived heliospheric delays data points, respectively. The blue line … view at source ↗
Figure 4
Figure 4. Figure 4: shows the posterior probability distributions for the param￾eters describing the stochastic interstellar DM variations and the heliospheric density at 1 AU for PSR J1909−3744 and the uncorre￾lated CRN when using various heliosphere models. The power-law PSD describing the stochastic interstellar DM variations is shal￾lower for PSR J1909−3744 when using the “SWIPS” model, whereas for “SWmean+SWGP” and “SWIP… view at source ↗
Figure 5
Figure 5. Figure 5: Gaussian-process time-domain realisations for various noise processes for the PSR J1909−3744. Top left: the total heliospheric DM - DM𝑆𝑊 (i.e. DMSWmean or DMSWIPS + DMSWGP ); top right: the inferred interstellar DM variations / DMGP; bottom left: then net DM variations with contributions from the interstellar (DMGP) and stochastic heliospheric DM variations (DMSWGP ); bottom right: the time delays of a com… view at source ↗
Figure 7
Figure 7. Figure 7: Measured inter-pulsar spatial correlations induced by the inferred common red noise component in the simulated PTA mock dataset. Top: inter-pulsar correlation obtained using simulation 1 where in the simulated PTA only heliospheric delays present (based on IPS-UCSD 3D tomography). These delays are modelled as a uncorrelated common red noise. Bottom: inter-pulsar correlation obtained using simulation 2 wher… view at source ↗
Figure 6
Figure 6. Figure 6: Histogram of the strength of spatial correlations assuming Hellings￾Downs, dipole and monopole ORFs for the MPTA DR2, computed while utilising different heliosphere models. The S/N values indicate the signal-to￾noise ratio strength of the recovered correlations for each heliosphere model. The teal, pink and gold curves show results for the “SWmean+SWGP”, “SWIPS” and “SWIPS+SWGP” heliosphere model, respecti… view at source ↗
Figure 8
Figure 8. Figure 8: Recovered spectral index of the stochastic interstellar DM variations for various pulsars as a function of ecliptic latitude (ELAT), where the injected value is 8/3 (Kolmogorov turbulence) using the simulation 2 mock PTA dataset. Different colours show the results from different noise models. For all these cases, the injected signals for the simulation were the stochastic interstellar DM variations, white … view at source ↗
Figure 9
Figure 9. Figure 9: Recovered common PSD of the stochastic heliospheric density variations (n 1 AU e ) assuming a free spectrum rather than a power law from simulation 3 mock PTA dataset. The simulated dataset contains heliospehric delays based on the IPS-UCSD 3D tomography heliosphere model but modelled using the “SWmean+SWGP” model. The y-axis shows the power in the log-scale whereas the x axis shows the Fourier components … view at source ↗

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Reference graph

Works this paper leans on

123 extracted references · 25 canonical work pages · 2 internal anchors

  1. [1]

    1929", month =

    A Relation between Distance and Radial Velocity among Extra-Galactic Nebulae. Proceedings of the National Academy of Science , year = "1929", month = "Mar", volume =. doi:10.1073/pnas.15.3.168 , adsurl =

    doi:10.1073/pnas.15.3.168 1929

  2. [2]

    1970", month =

    Rotation of the Andromeda Nebula from a Spectroscopic Survey of Emission Regions. , year = "1970", month = "Feb", volume =. doi:10.1086/150317 , adsurl =

    doi:10.1086/150317 1970

  3. [3]

    , keywords =

    Rotational properties of 21 SC galaxies with a large range of luminosities and radii, from NGC 4605 (R=4kpc) to UGC 2885 (R=122kpc). , keywords =. 1980. doi:10.1086/158003 , adsurl =

    doi:10.1086/158003 1980

  4. [4]

    Abbott, B. P. and Abbott, R. and Abbott, T. D. and Abernathy, M. R. and Acernese, F. and Ackley, K. and Adams, C. and Adams, T. and Addesso, P. and Adhikari, R. X. and Adya, V. B. and Affeldt, C. and Agathos, M. and Agatsuma, K. and Aggarwal, N. and Aguiar, O. D. and Aiello, L. and Ain, A. and Ajith, P. and Allen, B. and Allocca, A. and Altin, P. A. and A...

    doi:10.1103/physrevlett.116.061102

  5. [5]

    2007 , eprint=

    LISA sources and science , author=. 2007 , eprint=

    2007

  6. [6]

    Branchesi, Marica and Maggiore, Michele and Alonso, David and Badger, Charles and Banerjee, Biswajit and Beirnaert, Freija and Belgacem, Enis and Bhagwat, Swetha and Boileau, Guillaume and Borhanian, Ssohrab and Brown, Daniel David and Leong Chan, Man and Cusin, Giulia and Danilishin, Stefan L. and Degallaix, Jerome and De Luca, Valerio and Dhani, Arnab a...

    doi:10.1088/1475-7516/2023/07/068 2023

  7. [7]

    Detecting the cosmic gravitational wave background with the Big Bang Observer , volume=

    Corbin, Vincent and Cornish, Neil J , year=. Detecting the cosmic gravitational wave background with the Big Bang Observer , volume=. Classical and Quantum Gravity , publisher=. doi:10.1088/0264-9381/23/7/014 , number=

    doi:10.1088/0264-9381/23/7/014

  8. [8]

    Pulsars as gravitational wave detectors , ISBN=

    Hobbs, George , year=. Pulsars as gravitational wave detectors , ISBN=. doi:10.1007/978-3-642-17251-9_20 , booktitle=

    work page doi:10.1007/978-3-642-17251-9_20

  9. [9]

    and Zic, Andrew and Shannon, Ryan M

    Reardon, Daniel J. and Zic, Andrew and Shannon, Ryan M. and Hobbs, George B. and Bailes, Matthew and Di Marco, Valentina and Kapur, Agastya and Rogers, Axl F. and Thrane, Eric and Askew, Jacob and Bhat, N. D. Ramesh and Cameron, Andrew and Curyło, Małgorzata and Coles, William A. and Dai, Shi and Goncharov, Boris and Kerr, Matthew and Kulkarni, Atharva an...

    doi:10.3847/2041-8213/acdd02 2041

  10. [10]

    and Zic, Andrew and Shannon, Ryan M

    Reardon, Daniel J. and Zic, Andrew and Shannon, Ryan M. and Di Marco, Valentina and Hobbs, George B. and Kapur, Agastya and Lower, Marcus E. and Mandow, Rami and Middleton, Hannah and Miles, Matthew T. and Rogers, Axl F. and Askew, Jacob and Bailes, Matthew and Bhat, N. D. Ramesh and Cameron, Andrew and Kerr, Matthew and Kulkarni, Atharva and Manchester, ...

    doi:10.3847/2041-8213/acdd03 2041

  11. [11]

    and Arzoumanian, Zaven and Baker, Paul T

    Agazie, Gabriella and Anumarlapudi, Akash and Archibald, Anne M. and Arzoumanian, Zaven and Baker, Paul T. and Bécsy, Bence and Blecha, Laura and Brazier, Adam and Brook, Paul R. and Burke-Spolaor, Sarah and Burnette, Rand and Case, Robin and Charisi, Maria and Chatterjee, Shami and Chatziioannou, Katerina and Cheeseboro, Belinda D. and Chen, Siyuan and C...

    doi:10.3847/2041-8213/acdac6 2041

  12. [12]

    and Arumugam, P

    Antoniadis, J. and Arumugam, P. and Arumugam, S. and Babak, S. and Bagchi, M. and Bak Nielsen, A.-S. and Bassa, C. G. and Bathula, A. and Berthereau, A. and Bonetti, M. and Bortolas, E. and Brook, P. R. and Burgay, M. and Caballero, R. N. and Chalumeau, A. and Champion, D. J. and Chanlaridis, S. and Chen, S. and Cognard, I. and Dandapat, S. and Deb, D. an...

    doi:10.1051/0004-6361/202346844

  13. [13]

    Xu, Heng and Chen, Siyuan and Guo, Yanjun and Jiang, Jinchen and Wang, Bojun and Xu, Jiangwei and Xue, Zihan and Nicolas Caballero, R. and Yuan, Jianping and Xu, Yonghua and Wang, Jingbo and Hao, Longfei and Luo, Jingtao and Lee, Kejia and Han, Jinlin and Jiang, Peng and Shen, Zhiqiang and Wang, Min and Wang, Na and Xu, Renxin and Wu, Xiangping and Manche...

    doi:10.1088/1674-4527/acdfa5

  14. [14]

    The MeerKAT Pulsar Timing Array: the first search for gravitational waves with the MeerKAT radio telescope , volume=

    Miles, Matthew T and Shannon, Ryan M and Reardon, Daniel J and Bailes, Matthew and Champion, David J and Geyer, Marisa and Gitika, Pratyasha and Grunthal, Kathrin and Keith, Michael J and Kramer, Michael and Kulkarni, Atharva D and Nathan, Rowina S and Parthasarathy, Aditya and Singha, Jaikhomba and Theureau, Gilles and Thrane, Eric and Abbate, Federico a...

    doi:10.1093/mnras/stae2571

  15. [15]

    The MeerKAT Pulsar Timing Array: the 4.5-yr data release and the noise and stochastic signals of the millisecond pulsar population , volume=

    Miles, Matthew T and Shannon, Ryan M and Reardon, Daniel J and Bailes, Matthew and Champion, David J and Geyer, Marisa and Gitika, Pratyasha and Grunthal, Kathrin and Keith, Michael J and Kramer, Michael and Kulkarni, Atharva D and Nathan, Rowina S and Parthasarathy, Aditya and Porayko, Nataliya K and Singha, Jaikhomba and Theureau, Gilles and Abbate, Fed...

    doi:10.1093/mnras/stae2572

  16. [16]

    Manchester, R. N. and Hobbs, G. B. and Teoh, A. and Hobbs, M. , year=. The Australia Telescope National Facility Pulsar Catalogue , volume=. The Astronomical Journal , publisher=. doi:10.1086/428488 , number=

    doi:10.1086/428488

  17. [17]

    , year = 1968, month = feb, volume =

    Observation of a Rapidly Pulsating Radio Source. , year = 1968, month = feb, volume =. doi:10.1038/217709a0 , adsurl =

    doi:10.1038/217709a0 1968

  18. [18]

    Handbook of Pulsar Astronomy

  19. [19]

    Manchester, R. N. , year=. Millisecond Pulsars, their Evolution and Applications , volume=. Journal of Astrophysics and Astronomy , publisher=. doi:10.1007/s12036-017-9469-2 , number=

    doi:10.1007/s12036-017-9469-2

  20. [20]

    Lorimer, Duncan R. , year=. Binary and Millisecond Pulsars , volume=. Living Reviews in Relativity , publisher=. doi:10.12942/lrr-2008-8 , number=

    doi:10.12942/lrr-2008-8 2008

  21. [21]

    Philosophical Transactions of the Royal Society of London Series A , year = 1992, month = oct, volume =

    Pulsar Timing and Relativistic Gravity. Philosophical Transactions of the Royal Society of London Series A , year = 1992, month = oct, volume =. doi:10.1098/rsta.1992.0088 , adsurl =

    doi:10.1098/rsta.1992.0088 1992

  22. [22]

    Hobbs, G. B. and Edwards, R. T. and Manchester, R. N. , year=. tempo2, a new pulsar-timing package - I. An overview: tempo2, a new pulsar-timing package - I. Overview , volume=. Monthly Notices of the Royal Astronomical Society , publisher=. doi:10.1111/j.1365-2966.2006.10302.x , number=

    doi:10.1111/j.1365-2966.2006.10302.x 2006

  23. [23]

    and Cordes, James M

    Shannon, Ryan M. and Cordes, James M. , year=. ASSESSING THE ROLE OF SPIN NOISE IN THE PRECISION TIMING OF MILLISECOND PULSARS , volume=. The Astrophysical Journal , publisher=. doi:10.1088/0004-637x/725/2/1607 , number=

    work page doi:10.1088/0004-637x/725/2/1607

  24. [24]

    , keywords =

    Measurement and correction of variations in interstellar dispersion in high-precision pulsar timing. , keywords =. doi:10.1093/mnras/sts486 , archivePrefix =. 1211.5887 , primaryClass =

    Pith/arXiv arXiv doi:10.1093/mnras/sts486

  25. [26]

    , keywords =

    Upper limits on the isotropic gravitational radiation background from pulsar timing analysis. , keywords =. doi:10.1086/183954 , adsurl =

    doi:10.1086/183954

  26. [27]

    and Charisi, Maria and Dolch, Timothy and Hazboun, Jeffrey S

    Burke-Spolaor, Sarah and Taylor, Stephen R. and Charisi, Maria and Dolch, Timothy and Hazboun, Jeffrey S. and Holgado, A. Miguel and Kelley, Luke Zoltan and Lazio, T. Joseph W. and Madison, Dustin R. and McMann, Natasha and Mingarelli, Chiara M. F. and Rasskazov, Alexander and Siemens, Xavier and Simon, Joseph J. and Smith, Tristan L. , year=. The astroph...

    doi:10.1007/s00159-019-0115-7

  27. [28]

    Manchester, R. N. and Burgay, Marta and D’Amico, Nicolò and Esposito, Paolo and Pellizzoni, Alberto and Possenti, Andrea , year=. Pulsar Timing Arrays and their Applications , ISSN=. doi:10.1063/1.3615080 , booktitle=

    work page doi:10.1063/1.3615080

  28. [29]

    2023 , eprint=

    The Parkes Pulsar Timing Array Third Data Release , author=. 2023 , eprint=

    2023

  29. [30]

    The MeerKAT Pulsar Timing Array: first data release , volume=

    Miles, M T and Shannon, R M and Bailes, M and Reardon, D J and Keith, M J and Cameron, A D and Parthasarathy, A and Shamohammadi, M and Spiewak, R and van Straten, W and Buchner, S and Camilo, F and Geyer, M and Karastergiou, A and Kramer, M and Serylak, M and Theureau, G and Venkatraman Krishnan, V , year=. The MeerKAT Pulsar Timing Array: first data rel...

    doi:10.1093/mnras/stac3644

  30. [31]

    and Arzoumanian, Zaven and Baker, Paul T

    Agazie, Gabriella and Alam, Md Faisal and Anumarlapudi, Akash and Archibald, Anne M. and Arzoumanian, Zaven and Baker, Paul T. and Blecha, Laura and Bonidie, Victoria and Brazier, Adam and Brook, Paul R. and Burke-Spolaor, Sarah and Bécsy, Bence and Chapman, Christopher and Charisi, Maria and Chatterjee, Shami and Cohen, Tyler and Cordes, James M. and Cor...

    doi:10.3847/2041-8213/acda9a 2041

  31. [32]

    and Babak, S

    Antoniadis, J. and Babak, S. and Bak Nielsen, A.-S. and Bassa, C. G. and Berthereau, A. and Bonetti, M. and Bortolas, E. and Brook, P. R. and Burgay, M. and Caballero, R. N. and Chalumeau, A. and Champion, D. J. and Cłianlaridis, S. and Chen, S. and Cognard, I. and Desvignes, G. and Falxa, M. and Ferdman, R. D. and Franchini, A. and Gair, J. R. and Goncha...

    doi:10.1051/0004-6361/202346841

  32. [33]

    Tarafdar, Pratik and Nobleson, K and Rana, Prerna and Singha, Jaikhomba and Krishnakumar, M. A. and Joshi, Bhal Chandra and Paladi, Avinash Kumar and Kolhe, Neel and Batra, Neelam Dhanda and Agarwal, Nikita and Bathula, Adarsh and Dandapat, Subhajit and Desai, Shantanu and Dey, Lankeswar and Hisano, Shinnosuke and Ingale, Prathamesh and Kato, Ryo and Khar...

    doi:10.1017/pasa.2022.46 2022

  33. [34]

    The International Pulsar Timing Array: second data release , volume=

    Perera, B B P and DeCesar, M E and Demorest, P B and Kerr, M and Lentati, L and Nice, D J and Osłowski, S and Ransom, S M and Keith, M J and Arzoumanian, Z and Bailes, M and Baker, P T and Bassa, C G and Bhat, N D R and Brazier, A and Burgay, M and Burke-Spolaor, S and Caballero, R N and Champion, D J and Chatterjee, S and Chen, S and Cognard, I and Corde...

    doi:10.1093/mnras/stz2857

  34. [35]

    ENTERPRISE: Enhanced Numerical Toolbox Enabling a Robust PulsaR Inference SuitE

  35. [36]

    2021 , eprint=

    The Nanohertz Gravitational Wave Astronomer , author=. 2021 , eprint=

    2021

  36. [37]

    Edwards, R. T. and Hobbs, G. B. and Manchester, R. N. , year=. TEMPO2, a new pulsar timing package - II. The timing model and precision estimates , volume=. Monthly Notices of the Royal Astronomical Society , publisher=. doi:10.1111/j.1365-2966.2006.10870.x , number=

    doi:10.1111/j.1365-2966.2006.10870.x 2006

  37. [38]

    , keywords =

    An Improved Solar Wind Electron Density Model for Pulsar Timing. , keywords =. doi:10.1086/522227 , archivePrefix =. 0709.0135 , primaryClass =

    Pith/arXiv arXiv doi:10.1086/522227

  38. [39]

    , keywords =

    Measurement of the electron density and magnetic field of the solar wind using millisecond pulsars. , keywords =. doi:10.1111/j.1365-2966.2012.20688.x , archivePrefix =. 1202.2263 , primaryClass =

    doi:10.1111/j.1365-2966.2012.20688.x 2012

  39. [40]

    and Simon, Joseph and Madison, Dustin R

    Hazboun, Jeffrey S. and Simon, Joseph and Madison, Dustin R. and Arzoumanian, Zaven and Cromartie, H. Thankful and Crowter, Kathryn and DeCesar, Megan E. and Demorest, Paul B. and Dolch, Timothy and Ellis, Justin A. and Ferdman, Robert D. and Ferrara, Elizabeth C. and Fonseca, Emmanuel and Gentile, Peter A. and Jones, Glenn and Jones, Megan L. and Lam, Mi...

    doi:10.3847/1538-4357/ac5829

  40. [41]

    Journal of Geophysical Research (Space Physics) , keywords =

    On the sources of fast and slow solar wind. Journal of Geophysical Research (Space Physics) , keywords =. doi:10.1029/2004JA010918 , adsurl =

    work page doi:10.1029/2004ja010918

  41. [42]

    and Poedts, S

    Talpeanu, D.-C. and Poedts, S. and D’Huys, E. and Mierla, M. and Richardson, I. G. , year=. Interaction of coronal mass ejections and the solar wind: A force analysis , volume=. doi:10.1051/0004-6361/202243150 , journal=

    work page doi:10.1051/0004-6361/202243150

  42. [43]

    Advances in Space Research , year = 1999, month = jan, volume =

    Corotating interaction regions. Advances in Space Research , year = 1999, month = jan, volume =. doi:10.1016/S0273-1177(99)80013-1 , adsurl =

    work page doi:10.1016/s0273-1177(99)80013-1 1999

  43. [44]

    On the usefulness of existing solar wind models for pulsar timing corrections , volume=

    Tiburzi, C and Verbiest, J P W and Shaifullah, G M and Janssen, G H and Anderson, J M and Horneffer, A and Künsemöller, J and Osłowski, S and Donner, J Y and Kramer, M and Kumari, A and Porayko, N K and Zucca, P and Ciardi, B and Dettmar, R-J and Grießmeier, J-M and Hoeft, M and Serylak, M , year=. On the usefulness of existing solar wind models for pulsa...

    doi:10.1093/mnras/stz1278

  44. [45]

    and Shaifullah, G

    Tiburzi, C. and Shaifullah, G. M. and Bassa, C. G. and Zucca, P. and Verbiest, J. P. W. and Porayko, N. K. and van der Wateren, E. and Fallows, R. A. and Main, R. A. and Janssen, G. H. and Anderson, J. M. and Bak Nielsen, A.-S. and Donner, J. Y. and Keane, E. F. and Künsemöller, J. and Osłowski, S. and Grießmeier, J.-M. and Serylak, M. and Brüggen, M. and...

    doi:10.1051/0004-6361/202039846

  45. [46]

    Susarla, S. C. and Chalumeau, A. and Tiburzi, C. and Keane, E. F. and Verbiest, J. P. W. and Hazboun, J. S. and Krishnakumar, M. A. and Iraci, F. and Shaifullah, G. M. and Golden, A. and Bak Nielsen, A.-S. and Donner, J. and Grießmeier, J.-M. and Keith, M. J. and Osłowski, S. and Porayko, N. K. and Serylak, M. and Anderson, J. M. and Brüggen, M. and Ciard...

    doi:10.1051/0004-6361/202450680

  46. [47]

    2024 , eprint=

    A Gaussian-processes approach to fitting for time-variable spherical solar wind in pulsar timing data , author=. 2024 , eprint=

    2024

  47. [48]

    and Jackson, B.V

    Tiburzi, C. and Jackson, B.V. and Cota, L. and Shaifullah, G.M. and Fallows, R.A. and Tokumaru, M. and Zucca, P. , year=. Validation of heliospheric modeling algorithms through pulsar observations I: Interplanetary scintillation-based tomography , volume=. Advances in Space Research , publisher=. doi:10.1016/j.asr.2022.04.070 , number=

    work page doi:10.1016/j.asr.2022.04.070 2022

  48. [49]

    Frontiers in Astronomy and Space Sciences , year = 2023, month = jul, volume =

    Interplanetary scintillation observation and space weather modelling. Frontiers in Astronomy and Space Sciences , year = 2023, month = jul, volume =. doi:10.3389/fspas.2023.1159166 , adsurl =

    work page doi:10.3389/fspas.2023.1159166 2023

  49. [50]

    Frontiers in Astronomy and Space Sciences , keywords =

    Iterative Tomography: A Key to Providing Time- dependent 3-D Reconstructions of the Inner Heliosphere and the Unification of Space Weather Forecasting Techniques. Frontiers in Astronomy and Space Sciences , keywords =. doi:10.3389/fspas.2020.568429 , adsurl =

    doi:10.3389/fspas.2020.568429 2020

  50. [51]

    , keywords =

    Determination of solar-wind velocities using single-station measurements of interplanetary scintillation. , keywords =

  51. [52]

    Radio Science , keywords =

    A newly developed UHF radiotelescope for interplanetary scintillation observations: Solar Wind Imaging Facility. Radio Science , keywords =. doi:10.1029/2011RS004694 , adsurl =

    work page doi:10.1029/2011rs004694

  52. [53]

    2024 , eprint=

    Pulsar timing methods for evaluating dispersion measure time series , author=. 2024 , eprint=

    2024

  53. [54]

    and Backer, D.C

    Kramer, M. and Backer, D.C. and Cordes, J.M. and Lazio, T.J.W. and Stappers, B.W. and Johnston, S. , year=. Strong-field tests of gravity using pulsars and black holes , volume=. New Astronomy Reviews , publisher=. doi:10.1016/j.newar.2004.09.020 , number=

    doi:10.1016/j.newar.2004.09.020 2004

  54. [55]

    Structure of Matter below Nuclear Saturation Density , author =. Phys. Rev. Lett. , volume =. 1983 , month =. doi:10.1103/PhysRevLett.50.2066 , url =

    doi:10.1103/physrevlett.50.2066 1983

  55. [56]

    , keywords =

    Pulsar Distances and the Galactic Distribution of Free Electrons. , keywords =. doi:10.1086/172870 , adsurl =

    doi:10.1086/172870

  56. [57]

    , keywords =

    New Rotation Measures of Distant Pulsars in the Inner Galaxy and Magnetic Field Reversals. , keywords =. doi:10.1093/mnras/268.2.497 , adsurl =

    doi:10.1093/mnras/268.2.497

  57. [58]

    , keywords =

    Pulsar timing measurements and the search for gravitational waves. , keywords =. doi:10.1086/157593 , adsurl =

    doi:10.1086/157593

  58. [59]

    2023 , eprint=

    The International Pulsar Timing Array checklist for the detection of nanohertz gravitational waves , author=. 2023 , eprint=

    2023

  59. [60]

    40th COSPAR Scientific Assembly , year = 2014, volume =

    OMNI: A Description of Near-Earth Solar Wind Environment. 40th COSPAR Scientific Assembly , year = 2014, volume =

    2014

  60. [61]

    and Hobbs, G

    Tiburzi, C. and Hobbs, G. and Kerr, M. and Coles, W. A. and Dai, S. and Manchester, R. N. and Possenti, A. and Shannon, R. M. and You, X. P. , year=. A study of spatial correlations in pulsar timing array data , volume=. Monthly Notices of the Royal Astronomical Society , publisher=. doi:10.1093/mnras/stv2143 , number=

    doi:10.1093/mnras/stv2143

  61. [62]

    , keywords =

    Dispersion measure variations and their effect on precision pulsar timing. , keywords =. doi:10.1111/j.1365-2966.2007.11617.x , archivePrefix =. astro-ph/0702366 , primaryClass =

    doi:10.1111/j.1365-2966.2007.11617.x 2007

  62. [63]

    , keywords =

    Ulysses solar wind plasma observations from pole to pole. , keywords =. doi:10.1029/95GL03094 , adsurl =

    work page doi:10.1029/95gl03094

  63. [64]

    Essential Radio Astronomy

  64. [65]

    2015 , eprint=

    Timing analysis for 20 millisecond pulsars in the Parkes Pulsar Timing Array , author=. 2015 , eprint=

    2015

  65. [66]

    and Bailes, Matthew and Shannon, Ryan M

    Reardon, Daniel J. and Bailes, Matthew and Shannon, Ryan M. and Flynn, Chris and Askew, Jacob and Bhat, N. D. Ramesh and Chen, Zu-Cheng and Curyło, Małgorzata and Feng, Yi and Hobbs, George B. and Kapur, Agastya and Kerr, Matthew and Liu, Xiaojin and Manchester, Richard N. and Mandow, Rami and Mishra, Saurav and Russell, Christopher J. and Shamohammadi, M...

    doi:10.3847/2041-8213/ad614a 2041

  66. [67]

    , keywords =

    The impact of a stochastic gravitational-wave background on pulsar timing parameters. , keywords =. doi:10.1111/j.1365-2966.2011.19413.x , archivePrefix =. 1107.4014 , primaryClass =

    doi:10.1111/j.1365-2966.2011.19413.x 2011

  67. [68]

    and Cornish, Neil and Crowter, Kathryn and Demorest, Paul B

    Arzoumanian, Zaven and Brazier, Adam and Burke-Spolaor, Sarah and Chamberlin, Sydney and Chatterjee, Shami and Christy, Brian and Cordes, James M. and Cornish, Neil and Crowter, Kathryn and Demorest, Paul B. and Dolch, Timothy and Ellis, Justin A. and Ferdman, Robert D. and Fonseca, Emmanuel and Garver-Daniels, Nathan and Gonzalez, Marjorie E. and Jenet, ...

    doi:10.1088/0004-637x/813/1/65

  68. [69]

    Journal of Physics Conference Series , year = 2024, series =

    Pulsars as Clocks. Journal of Physics Conference Series , year = 2024, series =. doi:10.1088/1742-6596/2889/1/012001 , adsurl =

    work page doi:10.1088/1742-6596/2889/1/012001 2024

  69. [70]

    Noise in pulsar timing arrays , volume=

    Wang, Yan , year=. Noise in pulsar timing arrays , volume=. doi:10.1088/1742-6596/610/1/012019 , journal=

    work page doi:10.1088/1742-6596/610/1/012019

  70. [71]

    and Taylor, Stephen R

    Gersbach, Kyle A. and Taylor, Stephen R. and Meyers, Patrick M. and Romano, Joseph D. , year=. Spatial and spectral characterization of the gravitational-wave background with the PTA optimal statistic , volume=. Physical Review D , publisher=. doi:10.1103/physrevd.111.023027 , number=

    doi:10.1103/physrevd.111.023027

  71. [72]

    and Creighton, Jolien D

    Chamberlin, Sydney J. and Creighton, Jolien D. E. and Siemens, Xavier and Demorest, Paul and Ellis, Justin and Price, Larry R. and Romano, Joseph D. , year=. Time-domain implementation of the optimal cross-correlation statistic for stochastic gravitational-wave background searches in pulsar timing data , volume=. Physical Review D , publisher=. doi:10.110...

    doi:10.1103/physrevd.91.044048

  72. [73]

    2025 , eprint=

    Latitudinal dependence of the solar wind during periods of high and low activity through interplanetary scintillation , author=. 2025 , eprint=

    2025

  73. [74]

    libstempo: Python wrapper for Tempo2

  74. [75]

    and Archibald, Anne and Kerr, Matthew and Jennings, Ross J

    Luo, Jing and Ransom, Scott and Demorest, Paul and Ray, Paul S. and Archibald, Anne and Kerr, Matthew and Jennings, Ross J. and Bachetti, Matteo and van Haasteren, Rutger and Champagne, Chloe A. and Colen, Jonathan and Phillips, Camryn and Zimmerman, Josef and Stovall, Kevin and Lam, Michael T. and Jenet, Fredrick A. , year=. PINT: A Modern Software Packa...

    doi:10.3847/1538-4357/abe62f

  75. [76]

    Measurements of pulse jitter and single-pulse variability in millisecond pulsars using MeerKAT , volume=

    Parthasarathy, A and Bailes, M and Shannon, R M and van Straten, W and Osłowski, S and Johnston, S and Spiewak, R and Reardon, D J and Kramer, M and Venkatraman Krishnan, V and Pennucci, T T and Abbate, F and Buchner, S and Camilo, F and Champion, D J and Geyer, M and Hugo, B and Jameson, A and Karastergiou, A and Keith, M J and Serylak, M , year=. Measur...

    doi:10.1093/mnras/stab037

  76. [77]

    Exploring the Asymmetry of the Solar Corona Electron Density with Very Long Baseline Interferometry , volume=

    Aksim, Dan and Melnikov, Alexey and Pavlov, Dmitry and Kurdubov, Sergey , year=. Exploring the Asymmetry of the Solar Corona Electron Density with Very Long Baseline Interferometry , volume=. The Astrophysical Journal , publisher=. doi:10.3847/1538-4357/ab499a , number=

    work page doi:10.3847/1538-4357/ab499a

  77. [78]

    , keywords =

    The NANOGrav Nine-year Data Set: Measurement and Analysis of Variations in Dispersion Measures. , keywords =. doi:10.3847/1538-4357/aa73df , archivePrefix =. 1612.03187 , primaryClass =

    Pith/arXiv arXiv doi:10.3847/1538-4357/aa73df

  78. [79]

    , keywords =

    Time Variability of Pulsar Dispersion Measures. , keywords =. doi:10.1086/186206 , adsurl =

    work page doi:10.1086/186206

  79. [80]

    and Islo, Kristina and Taylor, Stephen R

    Vigeland, Sarah J. and Islo, Kristina and Taylor, Stephen R. and Ellis, Justin A. , year=. Noise-marginalized optimal statistic: A robust hybrid frequentist-Bayesian statistic for the stochastic gravitational-wave background in pulsar timing arrays , volume=. Physical Review D , publisher=. doi:10.1103/physrevd.98.044003 , number=

    doi:10.1103/physrevd.98.044003

  80. [81]

    2025 , eprint=

    Beyond diagonal approximations: improved covariance modeling for pulsar timing array data analysis , author=. 2025 , eprint=

    2025

Showing first 80 references.