pith. machine review for the scientific record. sign in

arxiv: 2605.05303 · v1 · submitted 2026-05-06 · 🌌 astro-ph.HE

Recognition: unknown

Multi-wavelength outburst activity from EP J174942.2-384834: a very faint X-ray transient discovered by Einstein Probe

F. Coti Zelati , A. Marino , Y. L. Wang , M. Veresvarska , N. Rea , S. Guillot , D. A. H. Buckley , N. Rawat
show 22 more authors
S. E. Motta Y. Xu Z. Li Y.-F. Huang H. Feng L. Tao M. Imbrogno G. Illiano M. C. Baglio H. Q. Cheng C. C. Jin H. Sun W. Yuan F. Carotenuto R. P. Fender A. Coleiro D. G\"otz H. L. Li P. Maggi Y. L. Qiu J. Wang L. P. Xin
Authors on Pith no claims yet

Pith reviewed 2026-05-08 15:46 UTC · model grok-4.3

classification 🌌 astro-ph.HE
keywords X-ray transientsblack hole candidatesaccretion disksoutburstsComptonizationmulti-wavelength observationsGalactic sourcesvery faint transients
0
0 comments X

The pith

A faint Galactic X-ray transient exhibits repeated outbursts whose hard spectra and optical correlations indicate a black hole accretor with a cool truncated disk.

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

The paper details the discovery of a new source that produced two major outbursts plus a rebrightening over seven months at very low X-ray luminosities. Its X-ray emission is modeled as thermal Comptonization of unusually soft seed photons with no detectable thermal disk component, keeping the spectrum hard as it slowly softens while fading. Optical and ultraviolet light brightens in step with the X-rays and displays a blue continuum plus broad absorption lines, consistent with viscous heating in an accretion disk. These combined traits lead to the classification of the object as a very faint X-ray transient black hole candidate. The study shows how coordinated multi-wavelength data can identify and characterize the faintest accreting systems.

Core claim

Multi-wavelength observations of the repeated outbursts reveal consistently hard X-ray spectra from thermal Comptonization of very soft seed photons, with no detected thermal disk component and a low seed-photon temperature that together imply a cool and possibly truncated accretion disk. The optical and ultraviolet counterpart brightens in tandem with the X-rays, showing a blue continuum and broad Balmer absorption features that support a disk-dominated origin with viscous heating as the primary mechanism and possible irradiation in the ultraviolet. No radio emission is detected. Taken together, these properties support classifying the source as a very faint X-ray transient black hole.

What carries the argument

Thermal Comptonization of soft seed photons in hard X-ray spectra without a detectable disk blackbody, paired with the optical/UV-X-ray luminosity correlation that traces disk emission.

If this is right

  • Very faint transients can display hard spectra from Comptonization even when the accretion disk is cool and truncated.
  • Optical and ultraviolet monitoring provides essential evidence for the disk origin of the outburst emission in these low-luminosity events.
  • Jet activity appears suppressed, as shown by the lack of detectable radio emission during the outbursts.
  • Such systems add to the known population of black hole candidates at the faint end of the X-ray transient distribution.

Where Pith is reading between the lines

These are editorial extensions of the paper, not claims the author makes directly.

  • Higher-sensitivity soft X-ray observations could test whether a faint disk component appears at still lower fluxes.
  • Long-term monitoring in quiescence might allow radial-velocity measurements to obtain a dynamical mass and confirm the compact-object type.
  • The truncation radius inferred from the seed-photon temperature offers a way to map inner-disk behavior across a range of low accretion rates.
  • Similar faint hard-spectrum transients without radio counterparts may represent a larger hidden population accessible to wide-field surveys.

Load-bearing premise

The black hole classification rests on interpreting the missing thermal disk component, low seed-photon temperature, and optical/UV correlation as incompatible with a neutron star without direct mass measurement or detection of pulsations or bursts.

What would settle it

Detection of coherent X-ray pulsations or a thermonuclear type-I burst in future observations would indicate a neutron star and rule out the black hole candidate status.

Figures

Figures reproduced from arXiv: 2605.05303 by A. Coleiro, A. Marino, C. C. Jin, D. A. H. Buckley, D. G\"otz, F. Carotenuto, F. Coti Zelati, G. Illiano, H. Feng, H. L. Li, H. Q. Cheng, H. Sun, J. Wang, L. P. Xin, L. Tao, M. C. Baglio, M. Imbrogno, M. Veresvarska, N. Rawat, N. Rea, P. Maggi, R. P. Fender, S. E. Motta, S. Guillot, W. Yuan, Y.-F. Huang, Y. L. Qiu, Y. L. Wang, Y. Xu, Z. Li.

Figure 1
Figure 1. Figure 1: Zoomed-in (30′′×30′′) V TR-band image extracted from SVOM/VT observations (2025 March 30–31), centered on the optical counterpart of EP J1749. The dotted magenta circle (radius 7.4 ′′) and the dashed blue circle (radius 2.4 ′′) mark the 90% confidence X-ray localization uncertainties from EP/FXT and Swift, respectively. The red crosshair in￾dicates the position of the optical counterpart as reported in Gai… view at source ↗
Figure 2
Figure 2. Figure 2: Face-on view of the Galactic disk show￾ing the LoS toward EP J1749 (illustration credit: NASA/JPL-Caltech/R. Hurt (SSC/Caltech)). The col￾ored segment traces the LoS over the distance range inferred from the Gaia parallax measurement (see text). The position of EP J1749 is marked with a star symbol. The inset shows a zoomed-in view around the position of EP J1749. 3.2. Multi-wavelength Temporal Evolution view at source ↗
Figure 3
Figure 3. Figure 3: Multi-wavelength temporal evolution of EP J1749. Panel 1: Observed 0.5–10 keV fluxes in cgs units (erg cm−2 s −1 ) along with the 3σ upper limits on the radio flux density in the L-band. Panel 2: X-ray photon index. Panel 3: Multi-filter UV photometry. Panel 4: Optical photometry. The orange curve and shaded area show the GP interpolation and uncertainty envelope for ATLAS o band data. Horizontal dashed li… view at source ↗
Figure 4
Figure 4. Figure 4: shows the PDS restricted to frequencies ≤5 Hz. At frequencies ≲0.1 Hz, the PDS exhibits in￾creasing variability power toward lower frequencies. To characterize this broadband noise, we modeled the PDS using a zero-centered Lorentzian plus a constant white￾noise component. We obtained maximum-likelihood es￾timates by minimizing the chi-squared statistic and as￾sessed parameter uncertainties using a Markov C… view at source ↗
Figure 5
Figure 5. Figure 5: illustrates how variability and spectral hard￾ness evolve with the source intensity. We quantified these relationships using Spearman’s rank correlation test. We found a moderate anti-correlation between rms ampli￾tude and count rate (Spearman coefficient ρ = −0.61, p = 0.11), although this is not statistically significant at the 5% level. In contrast, the HR strongly correlates with the count rate (ρ = +0… view at source ↗
Figure 6
Figure 6. Figure 6: Top: unfolded X-ray spectra of EP J1749 ex￾tracted over the 0.5–40 keV energy range from quasi-simul￾taneous EP/FXT and NuSTAR observations, along with the best-fit absorbed thermal Comptonization model (solid curves; for details, see Section 3.5.1). Bottom: post-fit residu￾als. Data from each instrument are shown in different colors. The spectra have been rebinned for visual purposes. 3.5.2. Spectral Evol… view at source ↗
Figure 7
Figure 7. Figure 7: Flux-calibrated spectra of the optical counterpart to EP J1749 obtained with SALT/RSS on 2025 June 1 (cyan) and June 5 (orange). The spectra show a blue continuum with multiple absorption features, including Balmer lines (Hϵ, Hδ, Hγ, Hβ; black labels), as well as interstellar absorption from the CN molecular band, the Ca II H&K doublet, the Na D doublet, and the diffuse interstellar bands (DIBs) at 4428, 5… view at source ↗
Figure 8
Figure 8. Figure 8: Left: X-ray photon index versus 0.5–10 keV luminosity, with 1σ error bars, for BH systems (black circles), NS systems (cyan diamonds), and EP J1749 (orange squares). Overlaid are 600 linear regression lines randomly drawn from the Monte Carlo analysis, color-coded by population. The NS and BH data are taken from R. Wijnands et al. (2015); R. M. Plotkin et al. (2017); A. W. Shaw et al. (2021). Right: Poster… view at source ↗
Figure 9
Figure 9. Figure 9: Correlation between ATLAS o-band or Swift/UVOT uvm2-band luminosities and quasi-simultane￾ous X-ray luminosities. The optical luminosities are corrected for a companion contribution estimated from the quiescent Gaia G-band flux (see Section 4.2.2). In some cases, error bars are smaller than the symbol size. The solid lines show the median posterior linear relations from the Bayesian re￾gression; shaded reg… view at source ↗
Figure 10
Figure 10. Figure 10: Radio vs. X-ray luminosity for BH (black circles) and NS (cyan diamonds) LMXBs during the hard state. EP J1749 is overplotted using orange squares (see Section 4.3 for details), while Swift J1727.8−1613 is highlighted with green triangles for comparison. Detections are shown with error bars, while upper limits on the radio luminosity are indicated with down￾ward-pointing caps. The inset displays only the … view at source ↗
read the original abstract

We report the discovery and multi-wavelength characterization of the Galactic transient EP J174942.2$-$384834, first detected by the Einstein Probe during a faint X-ray outburst in March 2025. Coordinated follow-up observations revealed two major outbursts and a rebrightening over a seven-month period. Broadband X-ray spectral modeling shows that the outburst emission was dominated by thermal Comptonization of very soft seed photons. The absence of a detected thermal disk component, together with the low inferred seed-photon temperature, is consistent with a cool and possibly truncated accretion disk. The X-ray spectrum remained consistently hard throughout the outburst activity, with a power-law photon index of $\Gamma \approx 1$-2, gradually softening as the flux declined. The optical/UV counterpart brightened in tandem with the X-ray emission and exhibited a blue continuum with broad Balmer absorption features. Together with the optical/UV - X-ray luminosity correlation, this supports a disk-dominated origin of the optical/UV outburst emission, with viscous heating likely playing a major role and irradiation possibly contributing, especially in the UV. No radio counterpart was detected, implying at most very faint jet activity. Taken together, the observed properties support the classification of EP J174942.2$-$384834 as a very faint X-ray transient black hole candidate. This study demonstrates the ability of Einstein Probe to uncover and characterize the faintest accreting compact objects in the Galaxy.

Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, simulated authors' rebuttal, and a circularity audit. Tearing a paper down is the easy half of reading it; the pith above is the substance, this is the friction.

Referee Report

1 major / 3 minor

Summary. The manuscript reports the discovery of the Galactic X-ray transient EP J174942.2-384834 by the Einstein Probe in March 2025, followed by coordinated multi-wavelength observations over seven months that captured two major outbursts and a rebrightening. Broadband X-ray spectra are modeled as thermal Comptonization of soft seed photons with consistently hard power-law indices (Γ ≈ 1-2) that soften as flux declines; no thermal disk component is detected and seed-photon temperatures are low, consistent with a cool/truncated disk. Optical/UV photometry and spectroscopy show correlated brightening with a blue continuum and broad Balmer absorption, supporting a disk-dominated origin with possible viscous heating and irradiation contributions. No radio counterpart is detected. These properties are interpreted as supporting classification of the source as a very faint X-ray transient black hole candidate.

Significance. If the classification holds, the result adds a new member to the sparse population of very faint X-ray transients and illustrates the Einstein Probe's ability to detect and enable characterization of the faintest accreting compact objects in the Galaxy. The multi-wavelength dataset provides a coherent observational picture of hard-state accretion at low luminosities, with the hard spectra, luminosity correlations, and non-detections aligning with expectations for a truncated disk in a black-hole system.

major comments (1)
  1. [§3] §3 (X-ray spectral analysis): the central claim that the data support a truncated-disk black-hole interpretation rests on the non-detection of a thermal disk component and the low seed-photon temperature; however, the manuscript does not report quantitative upper limits on any disk normalization or formal model-comparison statistics (e.g., Δχ² or BIC) between Comptonization-only and Comptonization-plus-disk models, which weakens the load-bearing step from 'no detected component' to 'truncated disk'.
minor comments (3)
  1. [Abstract] Abstract: the statement that the spectrum 'gradually softened as the flux declined' is qualitative; the text should report the actual range of Γ values and the corresponding flux levels at which the softening occurs.
  2. [Optical/UV analysis] Optical/UV section: the claimed optical/UV–X-ray luminosity correlation is invoked to argue for a disk-dominated origin, but the manuscript should state the fitted slope, Pearson coefficient, or p-value so that readers can assess the strength of the correlation.
  3. [Table 1] Table 1 or equivalent: ensure all reported luminosities include the exact distance assumption and the 1σ uncertainties propagated from the spectral fits.

Simulated Author's Rebuttal

1 responses · 0 unresolved

We thank the referee for their constructive review and recommendation for minor revision. We address the major comment below.

read point-by-point responses

  1. Referee: [§3] §3 (X-ray spectral analysis): the central claim that the data support a truncated-disk black-hole interpretation rests on the non-detection of a thermal disk component and the low seed-photon temperature; however, the manuscript does not report quantitative upper limits on any disk normalization or formal model-comparison statistics (e.g., Δχ² or BIC) between Comptonization-only and Comptonization-plus-disk models, which weakens the load-bearing step from 'no detected component' to 'truncated disk'.

    Authors: We agree that quantitative upper limits on disk normalization and formal model-comparison statistics would strengthen the interpretation. In the revised manuscript we have added diskbb+nthcomp fits to all spectra, reporting 90% upper limits on the disk normalization (typically <10-20 in XSPEC units, consistent with a truncated disk). We also tabulate Δχ² and BIC differences, confirming that adding the disk component yields no statistically significant improvement (Δχ² < 2-4 in most cases, with BIC favoring the single-component model). These results are now included in Section 3 and the spectral tables. revision: yes

Circularity Check

0 steps flagged

No significant circularity in observational classification

full rationale

The paper reports multi-wavelength observations of a transient source and classifies it as a very faint X-ray transient black hole candidate based on direct empirical properties: hard X-ray spectra (Γ≈1-2), absence of detected thermal disk, low seed-photon temperature, optical/UV-X-ray correlations, blue continuum with Balmer features, and non-detection in radio. These are compared to known systems without any claimed first-principles derivation, fitted-parameter prediction, or self-referential uniqueness theorem. No equations or models reduce to the target classification by construction; the conclusion is framed as 'supports the classification' from standard observational criteria. This is a self-contained empirical analysis with no load-bearing self-citations or ansatz smuggling.

Axiom & Free-Parameter Ledger

2 free parameters · 2 axioms · 0 invented entities

The central claim rests on standard X-ray binary spectral modeling assumptions and empirical correlations from the literature rather than new free parameters or invented entities.

free parameters (2)
  • photon index Gamma
    Fitted value ~1-2 from X-ray spectra; used to characterize hardness but not a new parameter invented here.
  • seed photon temperature
    Inferred low value from Comptonization modeling; fitted to data to support truncated disk interpretation.
axioms (2)
  • domain assumption Hard X-ray spectra with Gamma ~1-2 and absence of thermal disk component indicate truncated accretion disk in black hole systems
    Invoked in the spectral modeling section to link observations to black hole classification.
  • domain assumption Optical/UV-X-ray luminosity correlation implies disk-dominated emission with viscous heating
    Used to interpret the optical/UV brightening as accretion disk origin.

pith-pipeline@v0.9.0 · 5725 in / 1529 out tokens · 72544 ms · 2026-05-08T15:46:14.028078+00:00 · methodology

discussion (0)

Sign in with ORCID, Apple, or X to comment. Anyone can read and Pith papers without signing in.

Reference graph

Works this paper leans on

162 extracted references · 150 canonical work pages · 7 internal anchors

  1. [1]

    2024, RMxAA, 60, 403, doi: 10.22201/ia.01851101p.2024.60.02.18

    Ahmed, O., Degenaar, N., Wijnands, R., & Armas Padilla, M. 2024, RMxAA, 60, 403, doi: 10.22201/ia.01851101p.2024.60.02.18

    work page doi:10.22201/ia.01851101p.2024.60.02.18 2024

  2. [2]

    2023, ARA&A, 61, 329, doi: 10.1146/annurev-astro-052920-103508

    Aigrain, S., & Foreman-Mackey, D. 2023, ARA&A, 61, 329, doi: 10.1146/annurev-astro-052920-103508

    work page doi:10.1146/annurev-astro-052920-103508 2023

  3. [3]

    1997, in Astrophysics and Space Science

    Alexander, T. 1997, in Astrophysics and Space Science

    1997

  4. [4]

    218, Astronomical Time Series, ed

    Library, Vol. 218, Astronomical Time Series, ed. D. Maoz, A. Sternberg, & E. M. Leibowitz, 163, doi: 10.1007/978-94-015-8941-3 14

    work page doi:10.1007/978-94-015-8941-3

  5. [5]

    Median Period

    Alexander, T. 2013, arXiv e-prints, arXiv:1302.1508, doi: 10.48550/arXiv.1302.1508 Ar´ evalo, P., & Uttley, P. 2006, MNRAS, 367, 801, doi: 10.1111/j.1365-2966.2006.09989.x Armas Padilla, M., Corral-Santana, J. M., Borghese, A., et al. 2023, A&A, 677, A186, doi: 10.1051/0004-6361/202346797 Armas Padilla, M., Degenaar, N., Russell, D. M., &

    work page doi:10.48550/arxiv.1302.1508 2013

  6. [6]

    2013, MNRAS, 428, 3083, doi: 10.1093/mnras/sts255 Armas Padilla, M., Wijnands, R., Altamirano, D., et al

    Wijnands, R. 2013, MNRAS, 428, 3083, doi: 10.1093/mnras/sts255 Armas Padilla, M., Wijnands, R., Altamirano, D., et al. 2014, MNRAS, 439, 3908, doi: 10.1093/mnras/stu243

    work page doi:10.1093/mnras/sts255 2013

  7. [7]

    Arnaud, K. A. 1996, in Astronomical Society of the Pacific Conference Series, Vol. 101, Astronomical Data Analysis Software and Systems V, ed. G. H. Jacoby & J. Barnes, 17

    1996

  8. [8]

    C., Campana, S., et al

    Asquini, L., Baglio, M. C., Campana, S., et al. 2024, A&A, 692, A16, doi: 10.1051/0004-6361/202450816 Astropy Collaboration, Robitaille, T. P., Tollerud, E. J., et al. 2013, A&A, 558, A33, doi: 10.1051/0004-6361/201322068 Astropy Collaboration, Price-Whelan, A. M., Sip˝ ocz, B. M., et al. 2018, aj, 156, 123, doi: 10.3847/1538-3881/aabc4f Astropy Collabora...

    work page doi:10.1051/0004-6361/202450816 2024

  9. [9]

    2023, A&A, 675, A199, doi: 10.1051/0004-6361/202346522

    Avakyan, A., Neumann, M., Zainab, A., et al. 2023, A&A, 675, A199, doi: 10.1051/0004-6361/202346522

    work page doi:10.1051/0004-6361/202346522 2023

  10. [10]

    Stingray 2:

    Bachetti, M., Huppenkothen, D., Stevens, A., et al. 2024, Journal of Open Source Software, 9, 7389, doi: 10.21105/joss.07389

    work page doi:10.21105/joss.07389 2024

  11. [11]

    C., Alabarta, K., Russell, D

    Baglio, M. C., Alabarta, K., Russell, D. M., et al. 2025, A&A, 704, A198, doi: 10.1051/0004-6361/202556699

    work page doi:10.1051/0004-6361/202556699 2025

  12. [13]

    2022, bersavosh/XRB-LrLx pub: update 20220908, v220908 Zenodo, doi: 10.5281/zenodo.7059313

    Bahramian, A., & Rushton, A. 2022, bersavosh/XRB-LrLx pub: update 20220908, v220908 Zenodo, doi: 10.5281/zenodo.7059313

    work page doi:10.5281/zenodo.7059313 2022

  13. [14]

    O., Kennea, J

    Bahramian, A., Heinke, C. O., Kennea, J. A., et al. 2021, MNRAS, 501, 2790, doi: 10.1093/mnras/staa3868

    work page doi:10.1093/mnras/staa3868 2021

  14. [15]

    2021, The Astronomical Journal, 161, 147, doi: 10.3847/1538-3881/abd806

    Demleitner, M., & Andrae, R. 2021, AJ, 161, 147, doi: 10.3847/1538-3881/abd806

    work page internal anchor Pith review doi:10.3847/1538-3881/abd806 2021

  15. [16]

    1990, A&A, 227, L33

    Belloni, T., & Hasinger, G. 1990, A&A, 227, L33

    1990

  16. [17]

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

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

  17. [18]

    M., & Motta, S

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

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

  18. [19]

    Buckley, D. A. H., Swart, G. P., & Meiring, J. G. 2006, in Society of Photo-Optical Instrumentation Engineers (SPIE) Conference Series, Vol. 6267, Ground-based and Airborne Telescopes, ed. L. M. Stepp, 62670Z, doi: 10.1117/12.673750

    work page doi:10.1117/12.673750 2006

  19. [20]

    Instrument Design and Performance for Optical/Infrared Ground-based Telescopes , year = 2003, editor =

    Burgh, E. B., Nordsieck, K. H., Kobulnicky, H. A., et al. 2003, in Proc. SPIE, Vol. 4841, Instrument Design and Performance for Optical/Infrared Ground-based Telescopes, ed. M. Iye & A. F. M. Moorwood, 1463–1471, doi: 10.1117/12.460312

    work page doi:10.1117/12.460312 2003

  20. [21]

    J., Gilfanov, M., & Sunyaev, R

    Burke, M. J., Gilfanov, M., & Sunyaev, R. 2017, MNRAS, 466, 194, doi: 10.1093/mnras/stw2514

    work page doi:10.1093/mnras/stw2514 2017

  21. [22]

    The Swift X-ray Telescope

    Burrows, D. N., Hill, J. E., Nousek, J. A., et al. 2005, SSRv, 120, 165, doi: 10.1007/s11214-005-5097-2

    work page Pith review doi:10.1007/s11214-005-5097-2 2005

  22. [23]

    J., Garcia, M

    Callanan, P. J., Garcia, M. R., McClintock, J. E., et al. 1995, ApJ, 441, 786, doi: 10.1086/175402 CASA Team, Bean, B., Bhatnagar, S., et al. 2022, PASP, 134, 114501, doi: 10.1088/1538-3873/ac9642

    work page doi:10.1086/175402 1995

  23. [24]

    Cash, Parameter estimation in astronomy through application of the likelihood ratio.ApJ 228, 939–947 (1979), doi:10.1086/156922

    Cash, W. 1979, ApJ, 228, 939, doi: 10.1086/156922

    work page doi:10.1086/156922 1979

  24. [25]

    2020, in Society of Photo-Optical Instrumentation Engineers (SPIE) Conference Series, Vol

    Chen, Y., Cui, W., Han, D., et al. 2021, in Society of Photo-Optical Instrumentation Engineers (SPIE) Conference Series, Vol. 11444, Society of Photo-Optical Instrumentation Engineers (SPIE) Conference Series, ed. J.-W. A. den Herder, S. Nikzad, & K. Nakazawa, 114445B, doi: 10.1117/12.2562311

    work page doi:10.1117/12.2562311 2021

  25. [26]

    2025, Radiation Detection Technology and Methods, doi: 10.1007/s41605-025-00558-0

    Chen, Y., Wang, J., Yang, Y., et al. 2025, Radiation Detection Technology and Methods, doi: 10.1007/s41605-025-00558-0

    work page doi:10.1007/s41605-025-00558-0 2025

  26. [27]

    2025, Experimental Astronomy, 60, 15, doi: 10.1007/s10686-025-10025-9

    Cheng, H., Zhang, C., Ling, Z., et al. 2025, Experimental Astronomy, 60, 15, doi: 10.1007/s10686-025-10025-9

    work page doi:10.1007/s10686-025-10025-9 2025

  27. [28]

    Q., Zhao, Q

    Cheng, H. Q., Zhao, Q. C., Tao, L., et al. 2025, ApJL, 991, L41, doi: 10.3847/2041-8213/adf104

    work page doi:10.3847/2041-8213/adf104 2025

  28. [29]

    2013, The ‘universal’ radio/X-ray flux correlation: the case study of the black hole GX 339-4, MNRAS, 428, 2500, doi: 10.1093/mnras/sts215

    Corbel, S., Coriat, M., Brocksopp, C., et al. 2013, MNRAS, 428, 2500, doi: 10.1093/mnras/sts215

    work page doi:10.1093/mnras/sts215 2013

  29. [30]

    A., Fender R

    Corbel, S., Nowak, M. A., Fender, R. P., Tzioumis, A. K., & Markoff, S. 2003, A&A, 400, 1007, doi: 10.1051/0004-6361:20030090 28Coti Zelati et al

    work page doi:10.1051/0004-6361:20030090 2003

  30. [31]

    A., & Kaaret, P

    Corbel, S., Tomsick, J. A., & Kaaret, P. 2006, ApJ, 636, 971, doi: 10.1086/498230

    work page doi:10.1086/498230 2006

  31. [32]

    The SVOM mission, its profile and its system

    Cordier, B., Wei, J. Y., Zhang, S. N., et al. 2026, arXiv e-prints, arXiv:2604.24257. https://arxiv.org/abs/2604.24257

    work page internal anchor Pith review Pith/arXiv arXiv 2026

  32. [33]

    2009, MNRAS, 396, 1383, doi:10.1111/j.1365-2966.2009.14843.x

    Coriat, M., Corbel, S., Buxton, M. M., et al. 2009, MNRAS, 400, 123, doi: 10.1111/j.1365-2966.2009.15461.x

    work page doi:10.1111/j.1365-2966.2009.15461.x 2009

  33. [34]

    M., Casares, J., Mu˜ noz-Darias, T., et al

    Corral-Santana, J. M., Casares, J., Mu˜ noz-Darias, T., et al. 2016, A&A, 587, A61, doi: 10.1051/0004-6361/201527130

    work page doi:10.1051/0004-6361/201527130 2016

  34. [35]

    M., Rodr´ ıguez-Gil, P., Torres, M

    Corral-Santana, J. M., Rodr´ ıguez-Gil, P., Torres, M. A. P., et al. 2025, A&A, 702, A225, doi: 10.1051/0004-6361/202556452

    work page doi:10.1051/0004-6361/202556452 2025

  35. [37]

    7737, Observatory Operations: Strategies, Processes, and Systems III, ed

    Crawford, S. M., Still, M., Schellart, P., et al. 2010b, in Society of Photo-Optical Instrumentation Engineers (SPIE) Conference Series, Vol. 7737, Observatory Operations: Strategies, Processes, and Systems III, ed. D. R. Silva, A. B. Peck, & B. T. Soifer, 773725, doi: 10.1117/12.857000 C´ uneo, V. A., Alabarta, K., Zhang, L., et al. 2020, MNRAS, 496, 100...

    work page doi:10.1117/12.857000 2020

  36. [38]

    2023, MNRAS, 521, 2692, doi: 10.1093/mnras/stad714

    Dai, X., Kong, L., Bu, Q., et al. 2023, MNRAS, 521, 2692, doi: 10.1093/mnras/stad714

    work page doi:10.1093/mnras/stad714 2023

  37. [39]

    D., Andrews, J

    Decleir, M., Gordon, K. D., Andrews, J. E., et al. 2022, The Astrophysical Journal, 930, 15, doi: 10.3847/1538-4357/ac5dbe

    work page doi:10.3847/1538-4357/ac5dbe 2022

  38. [40]

    Deeming, T. J. 1975, Ap&SS, 36, 137, doi: 10.1007/BF00681947

    work page doi:10.1007/bf00681947 1975

  39. [41]

    2009, A&A, 495, 547, doi: 10.1051/0004-6361:200810654

    Degenaar, N., & Wijnands, R. 2009, A&A, 495, 547, doi: 10.1051/0004-6361:200810654

    work page doi:10.1051/0004-6361:200810654 2009

  40. [42]

    M., et al

    Degenaar, N., Wijnands, R., Cackett, E. M., et al. 2012, A&A, 545, A49, doi: 10.1051/0004-6361/201219470

    work page doi:10.1051/0004-6361/201219470 2012

  41. [43]

    M., et al

    Degenaar, N., Wijnands, R., Miller, J. M., et al. 2015, Journal of High Energy Astrophysics, 7, 137, doi: 10.1016/j.jheap.2015.03.005 Del Santo, M., Sidoli, L., Mereghetti, S., et al. 2007, A&A, 468, L17, doi: 10.1051/0004-6361:20077536 Di Salvo, T., Papitto, A., Marino, A., Iaria, R., & Burderi, L. 2023, in Handbook of X-ray and Gamma-ray Astrophysics, 1...

    work page doi:10.1016/j.jheap.2015.03.005 2015

  42. [44]

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

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

    work page doi:10.1007/s00159-007-0006-1 2007

  43. [45]

    2024, arXiv e-prints, arXiv:2403.03127, doi: 10.48550/arXiv.2403.03127

    Doroshenko, V. 2024, arXiv e-prints, arXiv:2403.03127, doi: 10.48550/arXiv.2403.03127

    work page doi:10.48550/arxiv.2403.03127 2024

  44. [46]

    M., & Lasota, J

    Dubus, G., Hameury, J. M., & Lasota, J. P. 2001, A&A, 373, 251, doi: 10.1051/0004-6361:20010632

    work page doi:10.1051/0004-6361:20010632 2001

  45. [47]

    2025, astropy/specutils: v1.20.3, v1.20.3 Zenodo, doi: 10.5281/zenodo.15658692 El Byad, H., Bachetti, M., Columbu, S., et al

    Earl, N., Tollerud, E., O’Steen, R., et al. 2025, astropy/specutils: v1.20.3, v1.20.3 Zenodo, doi: 10.5281/zenodo.15658692 El Byad, H., Bachetti, M., Columbu, S., et al. 2025, ApJ, 989, 202, doi: 10.3847/1538-4357/aded8a

    work page doi:10.5281/zenodo.15658692 2025

  46. [48]

    2009, MNRAS, 396, 1383, doi:10.1111/j.1365-2966.2009.14843.x

    Elebert, P., Reynolds, M. T., Callanan, P. J., et al. 2009, MNRAS, 395, 884, doi: 10.1111/j.1365-2966.2009.14562.x

    work page doi:10.1111/j.1365-2966.2009.14562.x 2009

  47. [49]

    A., McClintock, J

    Esin, A. A., McClintock, J. E., & Narayan, R. 1997, ApJ, 489, 865, doi: 10.1086/304829

    work page doi:10.1086/304829 1997

  48. [50]

    2009, MNRAS, 396, 1383, doi:10.1111/j.1365-2966.2009.14843.x

    Evans, P. A., Beardmore, A. P., Page, K. L., et al. 2009, MNRAS, 397, 1177, doi: 10.1111/j.1365-2966.2009.14913.x

    work page doi:10.1111/j.1365-2966.2009.14913.x 2009

  49. [51]

    Clayton, G. C. 2019, The Astrophysical Journal, 886, 108, doi: 10.3847/1538-4357/ab4c3a

    work page doi:10.3847/1538-4357/ab4c3a 2019

  50. [52]

    2024, A&A, 684, A124, doi: 10.1051/0004-6361/202347908

    Chaty, S. 2024, A&A, 684, A124, doi: 10.1051/0004-6361/202347908 F¨ urst, F., Tomsick, J. A., Yamaoka, K., et al. 2016, ApJ, 832, 115, doi: 10.3847/0004-637X/832/2/115 Gaia Collaboration. 2023, A&A, 674, A1, doi: 10.1051/0004-6361/202243940

    work page doi:10.1051/0004-6361/202347908 2024

  51. [53]

    2018, MNRAS, 478, L132, doi: 10.1093/mnrasl/sly083

    Gallo, E., Degenaar, N., & van den Eijnden, J. 2018, MNRAS, 478, L132, doi: 10.1093/mnrasl/sly083

    work page doi:10.1093/mnrasl/sly083 2018

  52. [54]

    2003, MNRAS, 340, 1214, doi: 10.1046/j.1365-8711.2003.06380.x

    Gallo, E., Fender, R. P., & Pooley, G. G. 2003, MNRAS, 344, 60, doi: 10.1046/j.1365-8711.2003.06791.x

    work page doi:10.1046/j.1365-8711.2003.06791.x 2003

  53. [55]

    Gallo, E., Miller-Jones, J. C. A., Russell, D. M., et al. 2014, MNRAS, 445, 290, doi: 10.1093/mnras/stu1599 Garc´ ıa, J., Dauser, T., Lohfink, A., et al. 2014, ApJ, 782, 76, doi: 10.1088/0004-637X/782/2/76

    work page doi:10.1093/mnras/stu1599 2014

  54. [56]

    2013, MNRAS, 434, 3454, doi: 10.1093/mnras/stt1257

    Gardner, E., & Done, C. 2013, MNRAS, 434, 3454, doi: 10.1093/mnras/stt1257

    work page doi:10.1093/mnras/stt1257 2013

  55. [57]

    2004, ApJ, 611, 1005, doi: 10.1086/422091

    Gehrels, N., Chincarini, G., Giommi, P., et al. 2004, ApJ, 611, 1005, doi: 10.1086/422091

    work page doi:10.1086/422091 2004

  56. [58]

    Gelman, A., & Rubin, D. B. 1992, Statistical Science, 7, 457, doi: 10.1214/ss/1177011136

    work page doi:10.1214/ss/1177011136 1992

  57. [59]

    Space Telescopes and Instrumentation 2016: Ultraviolet to Gamma Ray , year = 2016, editor =

    Gendreau, K. C., Arzoumanian, Z., Adkins, P. W., et al. 2016, in Society of Photo-Optical Instrumentation Engineers (SPIE) Conference Series, Vol. 9905, Space Telescopes and Instrumentation 2016: Ultraviolet to Gamma Ray, ed. J.-W. A. den Herder, T. Takahashi, & M. Bautz, 99051H, doi: 10.1117/12.2231304

    work page doi:10.1117/12.2231304 2016

  58. [60]

    M., Brasseur, C

    Ginsburg, A., Sip˝ ocz, B. M., Brasseur, C. E., et al. 2019, AJ, 157, 98, doi: 10.3847/1538-3881/aafc33

    work page doi:10.3847/1538-3881/aafc33 2019

  59. [61]

    J., Russell, D

    Goodwin, A. J., Russell, D. M., Galloway, D. K., et al. 2020, MNRAS, 498, 3429, doi: 10.1093/mnras/staa2588

    work page doi:10.1093/mnras/staa2588 2020

  60. [62]

    Gordon, C., & Arnaud, K. 2021, PyXspec: Python interface to XSPEC spectral-fitting program,, Astrophysics Source Code Library, record ascl:2101.014 http://ascl.net/2101.014 EP J1749: a new very faint X-ray transient29

    2021

  61. [63]

    Gordon, K. D. 2024, Journal of Open Source Software, 9, 7023, doi: 10.21105/joss.07023

    work page doi:10.21105/joss.07023 2024

  62. [64]

    D., Cartledge, S., & Clayton, G

    Gordon, K. D., Cartledge, S., & Clayton, G. C. 2009, The Astrophysical Journal, 705, 1320, doi: 10.1088/0004-637X/705/2/1320

    work page doi:10.1088/0004-637x/705/2/1320 2009

  63. [65]

    The Microchannel X-ray Telescope on board the SVOM mission: in-flight scientific performance

    Gordon, K. D., Misselt, K. A., Bouwman, J., et al. 2021, The Astrophysical Journal, 916, 33, doi: 10.3847/1538-4357/ac00b7 G¨ otz, D., Crepaldi, S., Doumayrou, E., et al. 2026, arXiv e-prints, arXiv:2604.24246. https://arxiv.org/abs/2604.24246

    work page internal anchor Pith review Pith/arXiv arXiv doi:10.3847/1538-4357/ac00b7 2021

  64. [66]

    Journal of Open Source Software , author =

    Green, G. 2018, The Journal of Open Source Software, 3, 695, doi: 10.21105/joss.00695

    work page doi:10.21105/joss.00695 2018

  65. [67]

    , keywords =

    Hale, C. L., McConnell, D., Thomson, A. J. M., et al. 2021, PASA, 38, e058, doi: 10.1017/pasa.2021.47

    work page doi:10.1017/pasa.2021.47 2021

  66. [68]

    Hameury, J. M. 2020, Advances in Space Research, 66, 1004, doi: 10.1016/j.asr.2019.10.022

    work page doi:10.1016/j.asr.2019.10.022 2020

  67. [69]

    C., Hunstead, R

    Hannikainen, D. C., Hunstead, R. W., Campbell-Wilson, D., & Sood, R. K. 1998, A&A, 337, 460, doi: 10.48550/arXiv.astro-ph/9805332

    work page internal anchor Pith review doi:10.48550/arxiv.astro-ph/9805332 1998

  68. [70]

    R., Millman, K

    Harris, C. R., Millman, K. J., van der Walt, S. J., et al. 2020, Nature, 585, 357, doi: 10.1038/s41586-020-2649-2

    work page doi:10.1038/s41586-020-2649-2 2020

  69. [71]

    A., Craig, W

    Harrison, F. A., Craig, W. W., Christensen, F. E., et al. 2013, ApJ, 770, 103, doi: 10.1088/0004-637X/770/2/103

    work page doi:10.1088/0004-637x/770/2/103 2013

  70. [72]

    O., Bahramian, A., Degenaar, N., & Wijnands, R

    Heinke, C. O., Bahramian, A., Degenaar, N., & Wijnands, R. 2015, MNRAS, 447, 3034, doi: 10.1093/mnras/stu2652

    work page doi:10.1093/mnras/stu2652 2015

  71. [73]

    O., Zheng, J., Maccarone, T

    Heinke, C. O., Zheng, J., Maccarone, T. J., et al. 2025, ApJS, 279, 57, doi: 10.3847/1538-4365/ade99a

    work page doi:10.3847/1538-4365/ade99a 2025

  72. [74]

    2020, oxkat: Semi-automated imaging of MeerKAT observations,, Astrophysics Source Code Library, record ascl:2009.003 http://ascl.net/2009.003

    Heywood, I. 2020, oxkat: Semi-automated imaging of MeerKAT observations,, Astrophysics Source Code Library, record ascl:2009.003 http://ascl.net/2009.003

    2020

  73. [75]

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

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

    work page doi:10.1007/s10509-005-1197-4 2005

  74. [76]

    K., Jonker, P

    Homan, J., Fridriksson, J. K., Jonker, P. G., et al. 2013, ApJ, 775, 9, doi: 10.1088/0004-637X/775/1/9

    work page doi:10.1088/0004-637x/775/1/9 2013

  75. [77]

    , keywords =

    Horne, K. 1986, PASP, 98, 609, doi: 10.1086/131801

    work page doi:10.1086/131801 1986

  76. [78]

    K., Carotenuto, F., Russell, T

    Hughes, A. K., Carotenuto, F., Russell, T. D., et al. 2025, MNRAS, 542, 1803, doi: 10.1093/mnras/staf1363

    work page doi:10.1093/mnras/staf1363 2025

  77. [79]

    Astronomical Data Analysis Software and Systems XXX , year = 2022, editor =

    Hugo, B. V., Perkins, S., Merry, B., Mauch, T., & Smirnov, O. M. 2022, in Astronomical Society of the Pacific Conference Series, Vol. 532, Astronomical Data Analysis Software and Systems XXX, ed. J. E. Ruiz, F. Pierfedereci, & P. Teuben, 541, doi: 10.48550/arXiv.2206.09179

    work page doi:10.48550/arxiv.2206.09179 2022

  78. [80]

    Hunter, J. D. 2007, Computing in Science & Engineering, 9, 90, doi: 10.1109/MCSE.2007.55

    work page doi:10.1109/mcse.2007.55 2007

  79. [81]

    apj , keywords =

    Huppenkothen, D., Bachetti, M., Stevens, A. L., et al. 2019, ApJ, 881, 39, doi: 10.3847/1538-4357/ab258d

    work page doi:10.3847/1538-4357/ab258d 2019

  80. [82]

    L., & Stella, L

    Israel, G. L., & Stella, L. 1996, ApJ, 468, 369, doi: 10.1086/177697

    work page doi:10.1086/177697 1996

Showing first 80 references.