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This paper reports the first measurement of jet collimation profiles in an X-ray binary, showing that SS 433's approaching jet follows a quasi-parabolic width profile and its opening angle drops from ~20° to ~3°.

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2026-08-04 03:15 UTC pith:Q72DKO4W

load-bearing objection First XRB collimation profile is a real step forward, but the W∝r^0.74±0.02 exponent carries a zero-point systematic of order ±0.1 that the paper never faces. the 4 major comments →

arxiv 2607.28122 v2 pith:Q72DKO4W submitted 2026-07-30 astro-ph.HE

The First Measurement of Jet Collimation Profiles in an X-ray Binary: the Case of SS 433

Xi Yan , Lang Cui , Zsolt Paragi , S\'andor Frey This is my paper
classification astro-ph.HE
keywords SS 433X-ray binaryjet collimationVLBIcore shiftjet opening anglerelativistic jetsaccreting black holes
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.

Using archival VLBI data spanning 1995–2000, this paper reports the first direct measurement of a jet collimation profile in an X-ray binary. For SS 433, the approaching jet's deconvolved width follows a quasi-parabolic power law W ∝ r^{0.74±0.02} over ~3×10^14 to 8×10^15 cm, and the intrinsic opening angle declines from ~20° to ~3° with distance. These results establish that jet collimation, previously studied mainly in active galactic nuclei, also operates in stellar-mass accreting systems. The paper additionally derives a frequency-dependent core-shift relation Δr ∝ ν^{-1.1±0.3} consistent with synchrotron self-absorption. A sympathetic reader would care because this connects jet physics across black-hole mass scales and opens a new observational window on X-ray binaries.

Core claim

We report the first measurement of jet collimation profiles in an X-ray binary, SS 433, using multi-epoch, multi-frequency VLBI imaging at 1.7, 5, 8.4, and 15 GHz. The approaching jet is well described by a quasi-parabolic width profile W ∝ r^{0.74±0.02} over deprojected distances of ~3×10^14–8×10^15 cm, and the intrinsic opening angle decreases gradually from ~20° to ~3° between 8×10^14 and 9×10^15 cm. The 2000 epoch shows oscillatory width features that preclude a single power-law fit, but still indicates an opening-angle decline. We also measure the core-shift relation Δr ∝ ν^{-1.1±0.3}, making SS 433 the first X-ray binary with constrained jet collimation, opening-angle evolution, and co

What carries the argument

The central object is the deconvolved jet width W as a function of deprojected distance r, derived from Gaussian fits to transverse intensity profiles in VLBI images restored with a circular beam. The power-law index a in W ∝ r^a (with a = 0, 0.5, 1 corresponding to cylindrical, parabolic, and conical geometries) carries the argument, together with the intrinsic opening angle φ_open = 2 arctan(W sin θ_view / 2 r_proj). The kinematic precession model supplies θ_view at each epoch, and frequency-dependent core-shift measurements locate the binary center, allowing the projected distances to be deprojected.

Load-bearing premise

The inference that the 2000 data show a genuine opening-angle decline from ~20° to ~3° assumes that the ~7 mas apparent broadening from the precessing jet's rotation over the sampled emission does not significantly bias the measured widths; if that smearing is underestimated, the 2000 opening angles and 'humps' would be artifacts.

What would settle it

Re-analyze the 2000 VLBI data by forward-modelling the jet as a precessing cone with the known kinematic parameters and convolving with the beam; if the observed width 'humps' and the final 3° opening angle are reproduced by the smearing alone, the progressive-collimation claim from that epoch collapses.

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

If this is right

  • SS 433 becomes the first X-ray binary with a measured quasi-parabolic jet collimation profile, implying that the collimation processes seen in AGN jets also operate in stellar-mass accretors.
  • The opening-angle decrease from ~20° to ~3° provides direct evidence that the jet is progressively confined on scales of 10^14–10^16 cm, connecting to earlier indirect evidence from flux-density decay and magnetic-field orientation.
  • The core-shift relation Δr ∝ ν^{-1.1±0.3}, consistent with synchrotron self-absorption, offers a new tool to estimate magnetic-field strengths and particle densities in X-ray binary jets.
  • The contrasting profiles between 1995/1998 (quasi-parabolic), 1999 (roughly cylindrical on 40–270 mas), and 2000 (oscillatory) suggest that SS 433's jet collimation can vary on timescales of months, providing a rare testbed for jet–environment interactions.

Where Pith is reading between the lines

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

  • If the quasi-parabolic index ~0.74 holds across epochs, it may indicate magnetic collimation (hoop stress) rather than external pressure confinement in this region, in line with the perpendicular magnetic-field orientation observed at <350 mas; comparing the index with AGN profiles could test whether the same physical mechanism scales with black-hole mass.
  • The 'humps' in the 2000 width profiles might be explained by precession smearing acting on an otherwise smooth jet; a testable extension is to forward-model a precessing conical jet convolved with the beam and check whether the residual oscillations disappear.
  • The core-shift relation could be combined with the collimation profile to estimate the jet's magnetic flux and total power, offering a new route to compare jet-launching models across mass scales.

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

4 major / 6 minor

Summary. The paper analyzes archival VLBI observations of SS 433 from 1995, 1998, and 2000 and measures deconvolved jet widths as a function of deprojected distance from the adopted binary center. The approaching jet in 1995/1998 is found to follow a quasi-parabolic profile W ∝ r^{0.74±0.02} over roughly 3×10^14–8×10^15 cm, while the receding jet follows W ∝ r^{0.46±0.23} with much larger scatter. The 2000 data show local oscillations that prevent a single power-law fit, but are used to claim a decline in intrinsic opening angle from ~20° to ~3°. The paper also measures frequency-dependent core positions at 1.7, 5, 8.4, and 15 GHz and derives a core-shift relation Δr ∝ ν^{-1.1±0.3}. The authors present these results as the first measurement of jet collimation, opening-angle evolution, and core-shift relation in an X-ray binary.

Significance. If the quantitative claims are robust, this is a valuable first step: it provides a direct collimation profile for a Galactic XRB, enabling comparison with AGN collimation on different mass scales. The archival VLBI data are public, the analysis follows standard methods, and the figures clearly present the measurements. The opening-angle decline and the quasi-parabolic index are falsifiable predictions that can be tested with future high-frequency VLBI. The main scientific value is in the 1995/1998 profile and the opening-angle evolution; the core-shift relation is a secondary but interesting result. However, the current error budget is substantially underestimated: the power-law exponent is quoted to ±0.02 without propagating the core-position zero-point uncertainty, and the core-shift index is effectively constrained by only two points. These issues must be addressed before the quantitative claims can be accepted.

major comments (4)
  1. [§3.1, Table 2, §3.3.1, Figure 2] The fitted exponent 0.74±0.02 is derived from distances measured relative to an adopted binary position whose own uncertainty is 0.8–1.7 mas (Table 2). The fitted range is only ~4–100 mas, so an origin shift of −1.7 mas changes the innermost distances by ~20% while leaving the outermost distances nearly unchanged; in the log-log fit this can bias the slope by ~0.1–0.15. The quoted ±0.02 therefore reflects only the fit statistics and not the dominant systematic. The fit should be repeated with the origin treated as a nuisance parameter with a prior from Table 2, or the profile should be shown for extreme plausible origin shifts, and the systematic error added to the quoted exponent.
  2. [§2.2, footnote 9, Figure 2] The per-bin width uncertainties are assigned as Θ_maj/10 by construction rather than derived from the Gaussian fits or from a full propagation of deconvolution, binning, and alignment errors. Because these manual uncertainties enter directly into the power-law fit, the reported ±0.02 uncertainty on the exponent is not a meaningful statistical error. A systematic error budget is needed, including the effect of the adopted bin size and of the correlation between adjacent bins.
  3. [§4.1, Figure 4, Table 2] The core-shift power-law index ν^{-1.1±0.3} is effectively driven by the 1.7 and 5 GHz points, which have significant offsets, while the 8.4 and 15 GHz offsets are each consistent with zero at about 1σ. The claim that a core-shift relation has been 'constrained' is therefore overstated. The authors should report what the fit gives using only the two significant points, propagate the full covariance, or clearly state the relation as a tentative two-point constraint.
  4. [§3.3.2, §4.5, Figure 3] The 2000 data are used to claim a decrease in intrinsic opening angle from 20°±4° at ~10 mas to 3°±1° at ~112 mas. The paper's own estimate in §4.5 is that precession rotates the outer jet by ~3.5°, adding ~7 mas of apparent width, comparable to the 1.7 GHz beam. This effect is not corrected. Since correcting for rotation would reduce the outer widths, the qualitative collimation trend is not erased, but the quoted opening-angle values and the 'humps' could be affected. Rather than asserting that the effect is 'unlikely to significantly bias' the profile, the authors should quantify it by forward-modelling a precessing jet or by showing the opening-angle evolution after excluding or correcting the outermost bins.
minor comments (6)
  1. [Abstract / §3.3.1] The abstract says the approaching jet 'exhibits a well-constrained quasi-parabolic profile' without noting that this applies only to the 1995 and 1998 data; the 2000 data are not fitted. Consider making this explicit in the abstract.
  2. [§3.3.2] The opening-angle uncertainties (20°±4°, 3°±1°) are quoted without a clear derivation. State how these errors are propagated from the width, distance, and viewing-angle uncertainties.
  3. [Appendix A / §4.2] The 1999 1.4 GHz profile is measured relative to the brightness peak because the binary location cannot be determined at that frequency. The 'roughly cylindrical' fit is therefore not directly comparable to the other profiles, and the claim of 'diverse jet collimation behaviors' in §4.2 should be softened accordingly.
  4. [Figure 2] The figure uses many colors and symbols, and it is difficult to distinguish the individual epochs and frequencies. A table of the binned widths with their errors, or a larger figure, would improve reproducibility.
  5. [Figure 4 caption] The fit line is shown as a black line; the caption does not state that the fit includes all four points or describe the fitting method. Add this information.
  6. [Throughout] There are a few typographical issues, e.g., 'for a early review' in the Introduction and the abbreviation 'FFA' inconsistently spelled. These are minor and do not affect the science.

Circularity Check

0 steps flagged

No circularity: the collimation profile and opening angles are empirical fits/derived quantities, not outputs built from the claimed result; the adopted kinematic center is an independent external VLBI constraint.

full rationale

The paper is an observational measurement paper. The central claims are (i) a quasi-parabolic width profile W ∝ r^0.74±0.02 fitted to deconvolved VLBI jet widths from 1995/1998, (ii) opening angles computed from the measured widths via Eq. (1), and (iii) a core-shift relation fitted to four measured core positions. None of these is a 'prediction' in the sense of being derived from the result itself: the width data are independent measurements, the power law is presented as a fit with quoted statistical uncertainty, and the opening angle is a standard transformation of measured W and r, not a quantity used to define W. The kinematic center is adopted from Paragi et al. (1999), which has an overlapping author (Zsolt Paragi), but that earlier work is an independent, externally testable VLBI constraint based on the well-established SS 433 kinematic model; it is not an output of the present analysis, and the width measurements are not fitted to it beyond using it as the origin. The paper itself flags the 2000 width oscillations as precluding a robust profile fit and discusses the jet-rotation smearing caveat in Section 4.5, but these are systematic-uncertainty concerns, not circular reductions. The zero-point/core-position sensitivity raised by the skeptic is a legitimate systematic error concern, but it does not make the derivation circular: shifting the origin changes the fitted slope, but the slope is still an empirical fit to external data, not an input renamed as an output. No equation in the paper reduces to its own input, and no load-bearing step is justified solely by a self-citation. Therefore no significant circularity is present; score 0.

Axiom & Free-Parameter Ledger

3 free parameters · 4 axioms · 0 invented entities

The measurements rest on externally supplied geometric and kinematic constants and on hand-chosen analysis thresholds; no new entities are invented and no free parameters are fitted to force the central claims.

free parameters (3)
  • Transverse profile detection threshold = 20×I_rms
    Measurements retained only if Gaussian amplitude exceeds 20× image rms; hand-chosen selection criterion that sets which distances contribute to the profile.
  • Jet-width bin size = Θ_maj/5
    Jet widths binned in steps of one-fifth of the beam major axis; hand-chosen smoothing scale that affects the scatter and shape of the width profile.
  • Assumed per-bin width uncertainty = Θ_maj/10
    Assumed per-bin uncertainty; conservative relative to the S/N estimate, but hand-assigned and directly sets the χ² of power-law fits, hence the quoted ±0.02 exponent error.
axioms (4)
  • domain assumption Kinematic precession model of SS 433: β=0.26, i=78.05°, ψ=20.92°, P=162.375 d (Eikenberry et al. 2001)
    Adopted via Eq. (2) to compute θ_view, which enters deprojected distances and opening angles (Eq. 1); errors in these parameters scale all quantitative opening angles.
  • domain assumption Distance to SS 433 of 5.5±0.2 kpc (Blundell & Bowler 2004)
    Used to convert mas to cm in Figures 2-5; a different distance changes absolute scales but not the power-law indices.
  • domain assumption The jet transverse brightness profile is a single Gaussian at all distances
    Required for the FWHM/deconvolution width (Section 2.2); non-Gaussian or limb-brightened profiles would bias W and hence opening angles.
  • domain assumption Optically thin components E1-E3 are stationary tracers whose relative shifts measure the core position
    Used in Section 3.1; if these components move or are not physically fixed, the tabulated core positions and the core-shift relation would be biased.

pith-pipeline@v1.3.0-alltime-deepseek · 15093 in / 13201 out tokens · 642857 ms · 2026-08-04T03:15:07.063428+00:00 · methodology

0 comments
read the original abstract

While significant progress has been achieved in active galactic nuclei (AGN), jet collimation profiles in X-ray binaries (XRBs) have not been directly measured. Here we report the first measurement of jet collimation profiles in an XRB using very long baseline interferometry data from SS 433. The approaching jet exhibits a well-constrained quasi-parabolic profile in the 1995 and 1998 data, whereas the prominent local oscillations present in the 2000 jet-width measurements preclude a robust characterization of the jet collimation profile. Nevertheless, the 2000 data suggest that the intrinsic jet opening angle decreases gradually from $\sim 20^\circ$ at 8$\times 10^{14}$ cm to $\sim 3^\circ$ at $9\times 10^{15}$ cm (deprojected), providing evidence for progressive jet collimation. The width and opening angle of the receding jet are also presented, although their interpretation is limited by the free--free absorption effect. In addition, we measure the frequency-dependent core positions at four bands and derive a core-shift relation. These results establish SS 433 as the first XRB in which jet collimation, opening-angle evolution, and core-shift relation are constrained.

Figures

Figures reproduced from arXiv: 2607.28122 by Lang Cui, S\'andor Frey, Xi Yan, Zsolt Paragi.

Figure 1
Figure 1. Figure 1: VLBI images of SS 433 obtained from different projects (see [PITH_FULL_IMAGE:figures/full_fig_p003_1.png] view at source ↗
Figure 2
Figure 2. Figure 2: Deconvolved jet width (upper panel) and intrinsic jet opening angle (lower panel) as a function of deprojected distance from the central binary on the approaching and receding sides of SS 433, derived from 1995 and 1998 datasets. The lower horizontal axis shows the deprojected distance in mas, while the upper horizontal axis shows the corresponding distance in cm, adopting a source distance of 5.5 kpc (K. … view at source ↗
Figure 3
Figure 3. Figure 3: Deconvolved jet width (upper panel) and intrinsic jet opening angle (lower panel) as a function of deprojected distance from the central binary on the approaching and receding sides of SS 433, derived from the three epochs in 2000. The jet viewing angle at each epoch is listed in [PITH_FULL_IMAGE:figures/full_fig_p006_3.png] view at source ↗
Figure 4
Figure 4. Figure 4: Approaching jet core position relative to the cen￾tral binary in R.A. as a function of frequency. The black solid line shows the best-fit power law. J1820+070, and Swift J1727.8–1613 (S. Prabu et al. 2023; C. M. Wood et al. 2025). In this work, we ex￾tend these studies by measuring the core shift of the approaching jet in SS 433 at 1.7, 5, 8.4, and 15 GHz. Using the results listed in [PITH_FULL_IMAGE:figu… view at source ↗
Figure 5
Figure 5. Figure 5: Collimation profiles of both the approaching and receding jets in SS 433, obtained by combining measurements from 1995, 1998, and 2000 (see Figures 2 and 3). ing medium. Consistent with this picture, our VLBI observations reveal a substantially larger opening an￾gle of ∼ 20◦ at (3–8)×1014 cm. However, the jet does not subsequently evolve into a freely expanding outflow. Instead, the opening angle gradually… view at source ↗
Figure 6
Figure 6. Figure 6: Left: CLEAN image of SS 433 observed with VLBA + VLA at 1.4 GHz. The image was restored using an elliptical Gaussian beam of 26.0 × 15.2 mas, oriented at a position angle of −12◦ . Contours start at 1.5 mJy beam−1 and increase by factors of √ 2. The jet viewing angle at this epoch is ∼ 97◦ . Right: deconvolved jet width of the eastern jet as a function of deprojected distance from the core, derived from th… view at source ↗

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Reviewed papers in the Pith corpus that reference this work. Sorted by Pith novelty score.

  1. Magnetic rigidity reveals the PeVatron acceleration region in SS433

    astro-ph.HE 2026-08 conditional novelty 6.0

    The radio-measured magnetic field in SS 433's inner jet declines as H^-0.5, so the jet retains enough magnetic rigidity at ~100 AU to accelerate protons to PeV energies.

Reference graph

Works this paper leans on

71 extracted references · 5 linked inside Pith · cited by 1 Pith paper

  1. [1]

    O., & Margon, B

    Abell, G. O., & Margon, B. 1979, Nature, 279, 701, doi: 10.1038/279701a0

    doi:10.1038/279701a0 1979

  2. [2]

    U., Albert, A., Alfaro, R., et al

    Abeysekara, A. U., Albert, A., Alfaro, R., et al. 2018, Nature, 562, 82, doi: 10.1038/s41586-018-0565-5

    doi:10.1038/s41586-018-0565-5 2018

  3. [3]

    2012, ApJL, 745, L28, doi: 10.1088/2041-8205/745/2/L28

    Asada, K., & Nakamura, M. 2012, ApJL, 745, L28, doi: 10.1088/2041-8205/745/2/L28

    doi:10.1088/2041-8205/745/2/l28 2012

  4. [4]

    K., Kadler, M., Ros, E., et al

    Baczko, A. K., Kadler, M., Ros, E., et al. 2024, A&A, 692, A205, doi: 10.1051/0004-6361/202450898

    doi:10.1051/0004-6361/202450898 2024

  5. [5]

    C., Sarazin, C

    Begelman, M. C., Sarazin, C. L., Hatchett, S. P., McKee, C. F., & Arons, J. 1980, ApJ, 238, 722, doi: 10.1086/158029

    doi:10.1086/158029 1980

  6. [6]

    M., & Bowler, M

    Blundell, K. M., & Bowler, M. G. 2004, ApJL, 616, L159, doi: 10.1086/426542

    doi:10.1086/426542 2004

  7. [7]

    M., Laing, R., Lee, S., & Richards, A

    Blundell, K. M., Laing, R., Lee, S., & Richards, A. 2018, ApJL, 867, L25, doi: 10.3847/2041-8213/aae890

    doi:10.3847/2041-8213/aae890 2018

  8. [8]

    Podsiadlowski, P., & Rupen, M. P. 2001, ApJL, 562, L79, doi: 10.1086/324573

    doi:10.1086/324573 2001

  9. [9]

    2021, A&A, 647, A67, doi: 10.1051/0004-6361/202039612

    Boccardi, B., Perucho, M., Casadio, C., et al. 2021, A&A, 647, A67, doi: 10.1051/0004-6361/202039612

    doi:10.1051/0004-6361/202039612 2021

  10. [10]

    V., & Fabrika, S

    Borisov, N. V., & Fabrika, S. N. 1987, Soviet Astronomy Letters, 13, 200

    1987

  11. [11]

    1996, A&A, 312, 306

    Brinkmann, W., Aschenbach, B., & Kawai, N. 1996, A&A, 312, 306

    1996

  12. [12]

    2007, A&A, 463, 611, doi: 10.1051/0004-6361:20065570

    Burwitz, V. 2007, A&A, 463, 611, doi: 10.1051/0004-6361:20065570

    doi:10.1051/0004-6361:20065570 2007

  13. [13]

    M., Dodin, A

    Cherepashchuk, A. M., Dodin, A. V., & Postnov, K. A. 2025, Physics Uspekhi, 68, 1042, doi: 10.3367/UFNe.2025.05.039904

    doi:10.3367/ufne.2025.05.039904 2025

  14. [14]

    F., & Rodr ´ ıguez, L

    Dhawan, V., Mirabel, I. F., & Rodr ´ ıguez, L. F. 2000, ApJ, 543, 373, doi: 10.1086/317088 D ´ ıaz Trigo, M., Miller-Jones, J. C. A., Migliari, S.,

    doi:10.1086/317088 2000

  15. [15]

    W., & Tzioumis, T

    Broderick, J. W., & Tzioumis, T. 2013, Nature, 504, 260, doi: 10.1038/nature12672

    doi:10.1038/nature12672 2013

  16. [16]

    M., Holdaway, M., Goss, W

    Dubner, G. M., Holdaway, M., Goss, W. M., & Mirabel, I. F. 1998, AJ, 116, 1842, doi: 10.1086/300537

    doi:10.1086/300537 1998

  17. [17]

    S., Cameron, P

    Eikenberry, S. S., Cameron, P. B., Fierce, B. W., et al. 2001, ApJ, 561, 1027, doi: 10.1086/323380

    doi:10.1086/323380 2001

  18. [18]

    C., & Rees, M

    Fabian, A. C., & Rees, M. J. 1979, MNRAS, 187, 13P, doi: 10.1093/mnras/187.1.13P

    doi:10.1093/mnras/187.1.13p 1979

  19. [19]

    2004, Astrophys

    Fabrika, S. 2004, Astrophys. Space Phys. Res., 12, 1, doi: 10.48550/arXiv.astro-ph/0603390

    Pith/arXiv arXiv doi:10.48550/arxiv.astro-ph/0603390 2004

  20. [20]

    2014, SSRv, 183, 323, doi: 10.1007/s11214-014-0069-z

    Fender, R., & Gallo, E. 2014, SSRv, 183, 323, doi: 10.1007/s11214-014-0069-z

    doi:10.1007/s11214-014-0069-z 2014

  21. [21]

    A., Garc ´ ıa, F., Combi, J

    Fogantini, F. A., Garc ´ ıa, F., Combi, J. A., et al. 2023, A&A, 669, A149, doi: 10.1051/0004-6361/202243951

    doi:10.1051/0004-6361/202243951 2023

  22. [22]

    Gandhi, P., & Boorman, P. G. 2026, An intrinsic decline of accretion activity in GRS 1915+105, https://arxiv.org/abs/2607.06200

    Pith/arXiv arXiv 2026

  23. [23]

    2018, Nature Astronomy, 2, 472, doi: 10.1038/s41550-018-0431-2

    Giovannini, G., Savolainen, T., Orienti, M., et al. 2018, Nature Astronomy, 2, 472, doi: 10.1038/s41550-018-0431-2

    doi:10.1038/s41550-018-0431-2 2018

  24. [24]

    Greisen, E. W. 2003, AIPS, the VLA, and the VLBA, ed. A. Heck (Dordrecht: Springer Netherlands), 109–125, doi: 10.1007/0-306-48080-8 7

    doi:10.1007/0-306-48080-8 2003

  25. [25]

    2011, Nature, 477, 185, doi: 10.1038/nature10387

    Hada, K., Doi, A., Kino, M., et al. 2011, Nature, 477, 185, doi: 10.1038/nature10387

    doi:10.1038/nature10387 2011

  26. [26]

    2015, ApJ, 807, 15, doi: 10.1088/0004-637X/807/1/15

    Haga, T., Doi, A., Murata, Y., et al. 2015, ApJ, 807, 15, doi: 10.1088/0004-637X/807/1/15

    doi:10.1088/0004-637x/807/1/15 2015

  27. [27]

    M., & Johnston, K

    Hjellming, R. M., & Johnston, K. J. 1981a, ApJL, 246, L141, doi: 10.1086/183571

    doi:10.1086/183571

  28. [28]

    M., & Johnston, K

    Hjellming, R. M., & Johnston, K. J. 1981b, Nature, 290, 100, doi: 10.1038/290100a0

    doi:10.1038/290100a0

  29. [29]

    M., & Johnston, K

    Hjellming, R. M., & Johnston, K. J. 1988, ApJ, 328, 600, doi: 10.1086/166318

    doi:10.1086/166318 1988

  30. [30]

    Mioduszewski, A. J. 2016, MNRAS, 461, 312, doi: 10.1093/mnras/stw1322

    doi:10.1093/mnras/stw1322 2016

  31. [31]

    2014, Journal of Korean Astronomical Society, 47, 195, doi: 10.5303/JKAS.2014.47.5.195

    Kim, J.-Y., & Trippe, S. 2014, Journal of Korean Astronomical Society, 47, 195, doi: 10.5303/JKAS.2014.47.5.195

    doi:10.5303/jkas.2014.47.5.195 2014

  32. [32]

    1981, ApJ, 243, 700, doi: 10.1086/158638

    Konigl, A. 1981, ApJ, 243, 700, doi: 10.1086/158638

    doi:10.1086/158638 1981

  33. [33]

    1994, PASJ, 46, L147, doi: 10.1093/pasj/46.4.L147

    Kotani, T., Kawai, N., Aoki, T., et al. 1994, PASJ, 46, L147, doi: 10.1093/pasj/46.4.L147

    doi:10.1093/pasj/46.4.l147 1994

  34. [34]

    P., Krichbaum, T

    Lee, S.-S., Lobanov, A. P., Krichbaum, T. P., et al. 2008, AJ, 136, 159, doi: 10.1088/0004-6256/136/1/159 LHAASO Collaboration, Cao, Z., Aharonian, F., et al. 2025, National Science Review, 12, nwaf496, doi: 10.1093/nsr/nwaf496

    doi:10.1088/0004-6256/136/1/159 2008

  35. [35]

    1984, ARA&A, 22, 507, doi: 10.1146/annurev.aa.22.090184.002451

    Margon, B. 1984, ARA&A, 22, 507, doi: 10.1146/annurev.aa.22.090184.002451

    arXiv 1984

  36. [36]

    C., et al

    Marino, A., Rea, N., Zelati, F. C., et al. 2026, The Astronomer’s Telegram, 17869, 1

    2026

  37. [37]

    L., Canizares, C

    Marshall, H. L., Canizares, C. R., Hillwig, T., et al. 2013, ApJ, 775, 75, doi: 10.1088/0004-637X/775/1/75

    doi:10.1088/0004-637x/775/1/75 2013

  38. [38]

    L., Canizares, C

    Marshall, H. L., Canizares, C. R., & Schulz, N. S. 2002, ApJ, 564, 941, doi: 10.1086/324398

    doi:10.1086/324398 2002

  39. [39]

    Miller-Jones, J. C. A., Blundell, K. M., Rupen, M. P., et al. 2004, ApJ, 600, 368, doi: 10.1086/379706

    doi:10.1086/379706 2004

  40. [40]

    Miller-Jones, J. C. A., Fender, R. P., & Nakar, E. 2006, MNRAS, 367, 1432, doi: 10.1111/j.1365-2966.2006.10092.x

    arXiv 2006

  41. [41]

    Miller-Jones, J. C. A., Migliari, S., Fender, R. P., et al. 2008, ApJ, 682, 1141, doi: 10.1086/589144 12

    doi:10.1086/589144 2008

  42. [42]

    Miller-Jones, J. C. A., Rupen, M. P., Fender, R. P., et al. 2007, MNRAS, 375, 1087, doi: 10.1111/j.1365-2966.2007.11381.x

    arXiv 2007

  43. [43]

    G., & Waltman, E

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

    doi:10.1086/320965 2001

  44. [44]

    2026, The Astronomer’s Telegram, 17865, 1

    Motta, S., Fender, R., X-KAT Collaboration, et al. 2026, The Astronomer’s Telegram, 17865, 1

    2026

  45. [45]

    H., Algaba, J

    Ng, Z. H., Algaba, J. C., & Abidin, Z. Z. 2025, MNRAS, 542, 417, doi: 10.1093/mnras/staf1268

    doi:10.1093/mnras/staf1268 2025

  46. [46]

    E., Lockhart, T

    Niell, A. E., Lockhart, T. G., & Preston, R. A. 1981, ApJ, 250, 248, doi: 10.1086/159369

    doi:10.1086/159369 1981

  47. [47]

    2022, ApJ, 940, 65, doi: 10.3847/1538-4357/ac97e5

    Okino, H., Akiyama, K., Asada, K., et al. 2022, ApJ, 940, 65, doi: 10.3847/1538-4357/ac97e5

    doi:10.3847/1538-4357/ac97e5 2022

  48. [48]

    C., et al

    Paragi, Z., Fejes, I., Vermeulen, R. C., et al. 2002, in Proceedings of the 6th EVN Symposium, ed. E. Ros, R. W. Porcas, A. P. Lobanov, & J. A. Zensus, 263, doi: 10.48550/arXiv.astro-ph/0207061

    Pith/arXiv arXiv doi:10.48550/arxiv.astro-ph/0207061 2002

  49. [49]

    C., et al

    Paragi, Z., Fejes, I., Vermeulen, R. C., et al. 2003, in New Views on Microquasars, ed. P. Durouchoux, Y. Fuchs, & J. Rodriguez, 261, doi: 10.48550/arXiv.astro-ph/0208125

    Pith/arXiv arXiv doi:10.48550/arxiv.astro-ph/0208125 2003

  50. [50]

    C., Fejes, I., et al

    Paragi, Z., Vermeulen, R. C., Fejes, I., et al. 1999, A&A, 348, 910, doi: 10.48550/arXiv.astro-ph/9907169

    Pith/arXiv arXiv doi:10.48550/arxiv.astro-ph/9907169 1999

  51. [51]

    C., & Spencer, R

    Paragi, Z., Vermeulen, R. C., & Spencer, R. 2012, arXiv: High Energy Astrophysical Phenomena. https://api.semanticscholar.org/CorpusID:118458868

    2012

  52. [52]

    2021, ApJ, 909, 76, doi: 10.3847/1538-4357/abd6ee

    Park, J., Hada, K., Nakamura, M., et al. 2021, ApJ, 909, 76, doi: 10.3847/1538-4357/abd6ee

    doi:10.3847/1538-4357/abd6ee 2021

  53. [53]

    Prabu, S., Miller-Jones, J. C. A., Bahramian, A., et al. 2023, MNRAS, 525, 4426, doi: 10.1093/mnras/stad2570

    doi:10.1093/mnras/stad2570 2023

  54. [54]

    Prabu, S., Miller-Jones, J. C. A., Bahramian, A., et al. 2026, Nature Astronomy, doi: 10.1038/s41550-026-02828-3

    doi:10.1038/s41550-026-02828-3 2026

  55. [55]

    1997, ApJ, 483, 868, doi: 10.1086/304274

    Safi-Harb, S., & ¨Ogelman, H. 1997, ApJ, 483, 868, doi: 10.1086/304274

    doi:10.1086/304274 1997

  56. [56]

    Shepherd, M. C. 1997, in Astronomical Society of the Pacific Conference Series, Vol. 125, Astronomical Data Analysis Software and Systems VI, ed. G. Hunt & H. Payne, 77

    1997

  57. [57]

    B., & Sanduleak, N

    Stephenson, C. B., & Sanduleak, N. 1977, ApJS, 33, 459, doi: 10.1086/190437

    doi:10.1086/190437 1977

  58. [58]

    2004, MNRAS, 354, 1239, doi: 10.1111/j.1365-2966.2004.08285.x

    Paragi, Z. 2004, MNRAS, 354, 1239, doi: 10.1111/j.1365-2966.2004.08285.x

    arXiv 2004

  59. [59]

    2026, A&A, 707, A278, doi: 10.1051/0004-6361/202557726

    Sunyaev, R., Khabibullin, I., Churazov, E., et al. 2026, A&A, 707, A278, doi: 10.1051/0004-6361/202557726

    doi:10.1051/0004-6361/202557726 2026

  60. [60]

    2025, ApJL, 993, L24, doi: 10.3847/2041-8213/ae0e73

    Tsuji, N., Inoue, Y., Khangulyan, D., et al. 2025, ApJL, 993, L24, doi: 10.3847/2041-8213/ae0e73

    doi:10.3847/2041-8213/ae0e73 2025

  61. [61]

    Spencer, R. E. 1987, Nature, 328, 309, doi: 10.1038/328309a0

    doi:10.1038/328309a0 1987

  62. [62]

    C., Schilizzi, R

    Vermeulen, R. C., Schilizzi, R. T., Spencer, R. E., Romney, J. D., & Fejes, I. 1993, A&A, 270, 177

    1993

  63. [63]

    2019, A&A, 623, A47, doi: 10.1051/0004-6361/201834746

    Perraut, K. 2019, A&A, 623, A47, doi: 10.1051/0004-6361/201834746

    doi:10.1051/0004-6361/201834746 2019

  64. [64]

    2016, MNRAS, 456, 1579, doi: 10.1093/mnras/stv2814

    Wang, Y., & M´ endez, M. 2016, MNRAS, 456, 1579, doi: 10.1093/mnras/stv2814

    doi:10.1093/mnras/stv2814 2016

  65. [65]

    G., Stewart, G

    Watson, M. G., Stewart, G. C., Brinkmann, W., & King, A. R. 1986, MNRAS, 222, 261, doi: 10.1093/mnras/222.2.261

    doi:10.1093/mnras/222.2.261 1986

  66. [66]

    M., Miller-Jones, J

    Wood, C. M., Miller-Jones, J. C. A., Bahramian, A., et al. 2024, ApJL, 971, L9, doi: 10.3847/2041-8213/ad6572

    doi:10.3847/2041-8213/ad6572 2024

  67. [67]

    M., Miller-Jones, J

    Wood, C. M., Miller-Jones, J. C. A., Bahramian, A., et al. 2025, ApJL, 984, L53, doi: 10.3847/2041-8213/adc9b3

    doi:10.3847/2041-8213/adc9b3 2025

  68. [68]

    Yan, X., Cui, L., & Ho, L. C. 2025a, ApJ, 983, 169, doi: 10.3847/1538-4357/adc003

    doi:10.3847/1538-4357/adc003

  69. [69]

    P., & Shen, Z.-Q

    Yan, X., Lu, R.-S., Jiang, W., Krichbaum, T. P., & Shen, Z.-Q. 2023, ApJ, 957, 32, doi: 10.3847/1538-4357/acf8c1

    doi:10.3847/1538-4357/acf8c1 2023

  70. [70]

    2025b, ApJ, 991, 75, doi: 10.3847/1538-4357/adf84c

    Yan, X., Cui, L., Hada, K., et al. 2025b, ApJ, 991, 75, doi: 10.3847/1538-4357/adf84c

    doi:10.3847/1538-4357/adf84c

  71. [71]

    2026, ApJL, 1006, L15, doi: 10.3847/2041-8213/ae80c8

    Yan, X., Cui, L., Jiang, W., et al. 2026, ApJL, 1006, L15, doi: 10.3847/2041-8213/ae80c8

    doi:10.3847/2041-8213/ae80c8 2026