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The paper claims that the extended X-ray jets of SS433/W50 are strong recollimation shocks in a two-component outflow, and that these shocks accelerate protons to PeV energies with above 10% efficiency and electrons past 50 TeV, producing t

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2026-08-04 18:31 UTC pith:OMT5C6TJ

load-bearing objection Serious, detailed modeling paper that makes a credible case for recollimation shocks as the W50 extended jets' particle accelerators, but the PeV efficiency claim rests on a non-unique MHD parameter choice. the 3 major comments →

arxiv 2509.09883 v1 pith:OMT5C6TJ submitted 2025-09-11 astro-ph.GA astro-ph.HE

PeV particle acceleration and non-thermal emission in the `minimalist' model of the extended jets in W50/SS433

A.M. Bykov , S.M. Osipov , V.I. Romansky , Y.A. Uvarov , E. Churazov , I. Khabibullin This is my paper
classification astro-ph.GA astro-ph.HE
keywords SS433/W50microquasar jetsrecollimation shocksPeV cosmic raysdiffusive shock accelerationX-ray polarizationnonthermal emissionBell instability
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.

This paper tries to establish that the mysterious extended jets of the microquasar SS433/W50, tens of parsecs long, are formed by recollimation shocks where a fast collimated polar wind collides with the termination surface of a slower isotropic wind. It argues that those shocks are efficient particle accelerators, converting more than 10% of the jet power into protons above 50 TeV and about 0.5% into electrons above 50 TeV. A sympathetic reader would care because if true, SS433/W50 is a proven PeV cosmic-ray accelerator, the nonthermal X-ray and gamma-ray emission is leptonic, and the recently measured X-ray polarization finds a natural explanation in anisotropic magnetic turbulence behind the shock.

Core claim

The central claim is that the observed extended X-ray jets (regions e1, e2, and the Head) and the very-high-energy gamma-ray emission from W50 are produced by strong recollimation MHD shocks in a 'minimalist' two-component outflow: a collimated polar wind at 0.2c with half-angle 5 degrees embedded in an isotropic wind at 3000 km/s, each carrying about 10^39 erg/s. Using nonlinear Monte Carlo simulations of diffusive shock acceleration with Bell-instability magnetic field amplification, the paper derives particle spectra reaching PeV energies for protons and above 50 TeV for electrons. The downstream magnetic turbulence is strongly anisotropic, with the field preferentially parallel to the je

What carries the argument

The load-bearing object is the recollimation shock: where the collimated polar wind crosses the termination shock of the isotropic wind, the flow is decelerated and compressed by a strong MHD shock (compression ratio near 4). The paper couples two simulation tools: an axisymmetric MHD model of the two-component outflow to locate the shocks, and a nonlinear plane-parallel Monte Carlo model of diffusive shock acceleration that self-consistently amplifies magnetic fields via Bell's instability from the current of escaping cosmic rays. The anisotropic turbulence generated by the passage of Bell-amplified fluctuations and pre-existing jet turbulence through the shock front is what creates the dow

Load-bearing premise

The central claim collapses if the observed extended X-ray jets are not actually recollimation shocks in the assumed two-component wind: the model's shock speeds, densities, and magnetic fields all depend on that specific geometry, and the authors note that different parameter combinations can reproduce similar nebula morphologies.

What would settle it

Measure the X-ray polarization angle and degree in the e1 and e2 knots: if the polarization degree is below 20% or the electric vector is parallel rather than transverse to the jet, the anisotropic-turbulence mechanism fails. Alternatively, detection of a hadronic gamma-ray component from the jet itself at a level above the predicted leptonic emission would falsify the claim that the gamma-ray emission is purely leptonic.

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

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If this is right

  • If the central claim is right, the extended jets of SS433/W50 are not the narrow baryonic jet remnants but recollimation shocks in a two-component accretion-disk wind; the bright X-ray knots are shock fronts, not cooling regions.
  • The source is a PeV proton accelerator: the eastern outflow alone injects about 5e37 erg/s of protons above 50 TeV, and both outflows together about 1e38 erg/s, a substantial fraction of the galactic PeV cosmic-ray budget.
  • The gamma-ray emission detected above 100 TeV is leptonic inverse Compton radiation from electrons that escape the axial jet into a surrounding cocoon, not hadronic emission from the jet itself.
  • X-ray polarization with the electric vector transverse to the jet and degree above 20% is a robust prediction; it has already been reported and is consistent with the model.
  • If the electron accelerator can reach about 1 PeV (with slightly modified parameters), the Head region should emit synchrotron radiation at MeV energies with flux ~1e-12 erg/cm2/s, detectable by future MeV missions, providing a direct test of maximal proton energy.

Where Pith is reading between the lines

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

  • If the recollimation-shock mechanism is generic for supercritical accretion disks, then other microquasars and ultraluminous X-ray sources with similar two-component winds should show extended polarized X-ray jets and PeV proton escape; the model's geometry could be used to predict which nearby sources to search.
  • The model's success would imply that calorimetric estimates of cosmic-ray output from gamma-ray pion decay miss a large fraction of proton power from microquasars, since most PeV protons escape into low-density regions and collide only with distant molecular clouds; the gamma-ray flux from those clouds could be estimated from the toy diffusion model in Section VII.
  • The anisotropic-turbulence polarization mechanism, if confirmed, could be applied to other collisionless shocks (e.g., supernova remnants) to infer shock orientation from polarization maps; however, this is my inference, not the paper's claim.
  • The paper leaves the ambient medium parameters non-unique; a future degeneracy-breaking test is to map the full multiwavelength morphology (radio to TeV) and compare with the two alternative parameter sets, which predict different shock timing (about 100,000 years for the denser ambient case).

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

3 major / 6 minor

Summary. The paper presents a multi-stage model of the W50/SS433 extended jets in the framework of the 'minimalist' two-component outflow scenario of Churazov, Khabibullin, and Bykov (2024). Axisymmetric MHD simulations are used to identify recollimation shocks with the observed X-ray knots e1 and e2. A nonlinear Monte Carlo diffusive-shock-acceleration model, with upstream conditions taken from the MHD run, is applied to these shocks and yields proton spectra extending to PeV energies with a claimed efficiency above 10% of the jet power, and electron spectra normalized to the X-ray synchrotron flux via an electron-to-proton ratio K_ep=3.3e-3. The downstream magnetic-field anisotropy is modeled with MHD simulations of Bell-instability turbulence passing through the shock, and is used to predict polarized synchrotron X-ray emission. The same electron population is then used to compute inverse-Compton gamma-ray emission, with an additional cocoon component needed to reproduce the LHAASO and H.E.S.S. spectra. The paper claims consistency with XMM-Newton, NuSTAR, IXPE, H.E.S.S., and LHAASO observations, and argues that the system is a PeV proton accelerator of Galactic relevance.

Significance. If the central claim holds, the paper is significant: it offers a self-consistent physical mechanism (recollimation shocks in a two-component outflow) that simultaneously accounts for the morphology, X-ray spectra, X-ray polarization, and VHE gamma-ray emission of W50/SS433, and it identifies a plausible PeV cosmic-ray source with a concrete efficiency budget. The modeling is ambitious and combines MHD, kinetic Monte Carlo DSA, turbulence-transport simulations, and radiative transfer. The paper also makes falsifiable predictions, e.g., a MeV synchrotron flux from the head region for alternative shock parameters, and the polarization direction/degree profiles. However, the strength of the conclusions is currently limited by the acknowledged degeneracy of the MHD/ambient parameters and by several fitted parameters in the emission model. The PeV acceleration and >10% efficiency claims are therefore conditional on a specific, non-unique MHD solution.

major comments (3)
  1. [Sections II-III] The upstream conditions used in the Monte Carlo DSA simulations (u_sh=0.2c, n0=5e-6 cm^-3, T0=5e5 K, B0=0.2 uG, Bturb0=1 uG) are taken from a single axisymmetric MHD setup. The authors explicitly state in Section II that 'the ambient matter parameters used above are not unique' and that 'various combinations of these parameters can lead to a qualitatively similar morphology of the nebula.' Since the maximum proton energy and the acceleration efficiency depend sensitively on the shock velocity, density, and magnetic field, the claims of PeV proton acceleration and >10% efficiency (Section VII) are not robustly established. I request a sensitivity study over the degenerate parameter range, e.g. (rho_amb=0.005 cm^-3, T_amb=8e4 K) versus (rho_amb=0.05 cm^-3, T_amb=8.6e3 K), showing the resulting shock conditions and whether the PeV proton conclusion survives. Without this, the central claim
  2. [Section VI, Fig. 12] The gamma-ray agreement is not a pure prediction of the shock-acceleration model. The jet-only inverse-Compton component (red curve) lies significantly below the LHAASO data, and the agreement is obtained by adding a cocoon component with an ad hoc escape fraction of ~30% and a diffusion coefficient D~1e28 cm^2/s chosen to match the observed VHE flux. These transport parameters are not derived from the MHD or Monte Carlo model. This tuning substantially weakens the claim that the model 'reproduces' the gamma-ray spectra. Please state how the escape fraction and diffusion coefficient are constrained by independent observations or by the microphysics of the model, or provide explicit predictions (e.g., cocoon extent, energy-dependent morphology) that can be tested with future data.
  3. [Section V] The agreement with X-ray observations is achieved after several fitting steps: K_ep=3.3e-3 is fixed to match the observed synchrotron flux, and the magnetic field profiles in the downstream are adjusted through parameters such as B_front, the constant residual field, and the turbulence normalization length l*. Consequently, the X-ray spectra and profiles are partly a reproduction with fitted parameters rather than an independent model prediction. The paper should clearly distinguish, for each comparison, which outputs are parameter-free predictions and which are fitted, and should quantify the number of free parameters relative to the number of observational constraints. This is important for assessing the weight of the 'model able to reproduce the observed spectra' claim.
minor comments (6)
  1. [Section II] The PLUTO MHD code is cited as [55], but reference [55] is Derouillat et al. (2018), which describes the Smilei particle-in-cell code, not PLUTO. The correct citation is Mignone et al. (2007), reference [47]. This should be corrected.
  2. [Section V (Eq. 5)] The function k(z) is used in Eq. (5) before its definition in the following line; consider moving the definition before the equation for readability.
  3. [Section VI] The terms 'thin target regime' and 'thick target regime' are used without definition. A brief definition or a reference would help the reader understand why the cocoon component changes the radiative regime.
  4. [Section VII] The text mentions a system age of ~30,000 years, while Section II mentions a later evolution time of ~100,000 years for the alternative ambient-parameter case. Please clarify which age corresponds to the main MHD setup and whether the age is an input or an output of the simulation.
  5. [Section IV, Fig. 5] The definition of B_perp as sqrt(Bx^2+By^2) is given, but the underlying quantities Bx and By are described as RMS values while B_parallel is also an RMS value. Please clarify whether the plotted perpendicular component is the RMS of the perpendicular field magnitude or the quadrature sum of the two RMS components; the notation is currently ambiguous.
  6. [Abstract and Section I] The phrase 'minimalist' model is hyphenated inconsistently ('minimalist' vs 'minimalists' scenario in Section II). Minor typographical consistency would improve the manuscript.

Circularity Check

2 steps flagged

X-ray flux normalization is fitted via the electron-to-proton ratio, and the gamma-ray agreement is obtained by tuning cocoon escape/diffusion parameters; the polarization prediction is independent.

specific steps
  1. fitted input called prediction [Section III, paragraph after Eq. (3)]
    "In our case of sub-relativistic shock in the outflow with weak magnetic field, we used the ratio 3.3×10−3 to fit the observed level of synchrotron radiation, as it is shown in Section V."

    The electron-to-proton ratio is a free normalization chosen so that the model synchrotron X-ray flux matches the observed X-ray data. Consequently, Section V's statement that the modeled synchrotron level 'fits well' is the fitting condition rather than an independent test. Because the same electron distribution is the source of the inverse-Compton gamma-ray emission, the gamma-ray flux normalization is inherited from this fit to X-ray data, so the gamma-ray 'prediction' is not independent of the observed X-ray normalization.

  2. fitted input called prediction [Section VI, gamma-ray emission model (around Fig. 12)]
    "In our model,∼30 % of the electrons accelerated at the shock front had escaped from the jet and diffused in the cocoon. This allows us to explain the observational data from LHAASO as shown in Figure 12."

    The base advection-only gamma-ray curve is explicitly below the observed data ('The red curve is significantly below the observational data'). The agreement with LHAASO is then achieved by adding a cocoon component whose escape fraction (~30%), diffusion coefficient (~10^28 cm2/s), and cocoon size (~30 pc) are selected to match the gamma-ray observations; H.E.S.S. is additionally accommodated by assigning a smaller emitting region. Section V also concedes that the transport model is 'not feasible now' and that the diffusion coefficient is 'parameterized.' Thus the gamma-ray reproduction is obtained by construction from parameters tuned to the gamma-ray data, not derived uniquely from the shock-acceleration model.

full rationale

The paper is not globally circular: the polarization prediction is generated from simulated anisotropic Bell-turbulence downstream and compared to IXPE data without being fitted to those polarization measurements, providing an independent external benchmark. The self-citations, e.g., the 'minimalist' model [46] and the shock-turbulence method [66], are not used as uniqueness theorems and the model is re-derived here, so they are not load-bearing in a circular way. However, the central emission claims are partially constructed from the data they claim to reproduce. The electron population is normalized by fitting the electron-to-proton ratio to the observed synchrotron X-ray level, so the X-ray spectral reproduction is the fitting condition; the inverse-Compton gamma-ray emission from the same electrons then inherits that fitted normalization. The gamma-ray agreement is further obtained by tuning the cocoon diffusion coefficient, escape fraction, and region size to match LHAASO and H.E.S.S. data. The paper also explicitly acknowledges that the ambient-medium parameters are not unique ('The ambient matter parameters used above are not unique... Various combinations of these parameters can lead to a qualitatively similar morphology'), which weakens the robustness of the PeV-efficiency claim but is a degeneracy/uncertainty issue rather than circularity. Overall, because some 'reproductions' reduce to fitted parameters while a genuinely independent polarization prediction survives, a score of 6 is appropriate.

Axiom & Free-Parameter Ledger

7 free parameters · 6 axioms · 0 invented entities

The model rests on the prior minimalist outflow geometry, a large set of tuned MHD/plasma parameters, a fixed electron injection ratio, and standard DSA/MHD assumptions. No new physical entities are introduced; the 'cocoon' is a spatial region, not a new entity.

free parameters (7)
  • Electron-to-proton ratio K_ep = 3.3e-3 at 1 GeV
    Fixed to match the observed level of synchrotron X-ray emission (Section III).
  • Free escape boundary L_FEB = 2 pc (first shock), 4 pc (second shock); alternative 6 pc
    Chosen by hand; sets maximal particle energy (Section III).
  • Upstream magnetic field B0 and turbulent Bturb0 = B0=0.2 uG, Bturb0=1.0 uG, Lls~3 pc
    Inputs to Monte Carlo DSA, chosen to match inferred conditions (Section III).
  • Ambient medium density and temperature = 0.005 cm^-3, 8e4 K; alternative 0.05 cm^-3, 8.6e3 K
    The authors state the parameters are not unique and yield similar morphologies (Section II).
  • Outflow parameters (velocities, opening angle, powers, magnetic fields) = vi=3000 km/s, vj=0.2c, half-angle 5 deg, Pi=Pj=2.1e39 erg/s, B_jet=100 uG, B_amb=1 uG
    Model inputs tuned to reproduce W50 morphology (Section II).
  • Magnetic field profile parameters for emission = e1: l*=3e17 cm, B_front=15 uG, B_const=8 uG; e2: l*=2e18 cm, B_front=9 uG, B_const=3 uG; model2: l*=3e19 cm
    Chosen to reproduce X-ray intensity profiles (Section V, Figures 8-10).
  • Cocoon diffusion coefficient and escape fraction = D~1e28 cm^2/s at 100 TeV, f_esc~30%
    Set to match LHAASO gamma-ray data; the jet-only IC flux is below the data (Section VI, Figure 12).
axioms (6)
  • domain assumption The minimalist two-component outflow model of SS433 (collimated polar wind + isotropic wind) describes the real system.
    Adopted from Churazov et al. 2024 (ref [46]); foundational to the whole paper (Section II).
  • domain assumption The extended X-ray jets are recollimation shocks formed by the interaction of the collimated outflow with the isotropic wind termination surface.
    Section II: 'The observed extended X-ray jets with bright knots in this model are associated with the formation of strong recollimation MHD shocks'.
  • domain assumption Diffusive shock acceleration with the implemented scattering prescription and no injection mechanism for protons is valid for these sub-relativistic shocks.
    Section III: the Monte Carlo model 'simulates the proton spectra within the basic assumptions of the proton scattering prescription'.
  • domain assumption Electrons are injected with a fixed number ratio and follow the proton spectral shape above m_p c^2.
    Section III: K_ep=3.3e-3 is assumed constant; this is a modeling assumption, not derived.
  • domain assumption Magnetic field amplification is dominated by Bell's instability driven by the escaping CR current, and the turbulence transport is captured by the 3D MHD simulations.
    Section IV: the two-stage PLUTO setup assumes this mechanism and scale separation.
  • domain assumption The non-thermal radiation is dominated by synchrotron and inverse Compton emission of electrons; hadronic gamma-ray emission is negligible due to low gas density.
    Section VI: 'most of the accelerated protons would escape... and then contribute to the gamma-ray emission from the denser gas' outside the model; within the jet/cocoon, leptonic emission dominates.

pith-pipeline@v1.3.0-alltime-deepseek · 17232 in / 15478 out tokens · 151716 ms · 2026-08-04T18:31:26.204084+00:00 · methodology

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Cite this review

Pith. "Pith review of PeV particle acceleration and non-thermal emission in the `minimalist' model of the extended jets in W50/SS433." pith.science (2026). https://pith.science/paper/OMT5C6TJ

@misc{pith2026250909883,
  author       = {Pith},
  title        = {Pith review of: PeV particle acceleration and non-thermal emission in the `minimalist' model of the extended jets in W50/SS433},
  year         = {2026},
  howpublished = {\url{https://pith.science/paper/OMT5C6TJ}},
  note         = {Machine review of arXiv:2509.09883}
}
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read the original abstract

The W50 nebula around microquasar SS~433, powered by supercritical accretion, features two `extended jets' (tens of pc long and a few pc wide) from which polarized X-ray and very high energy radiation above 100 TeV is detected. Here we present a model of very high energy particle acceleration in these extended jets. In the `minimalist' model (discussed in Churazov, Khabibullin, and Bykov, 2024), a collimated outflow aligned with the rotation axis is propagating through a more isotropic wind produced by the accretion disk. The observed extended X-ray jets with bright knots in this model are associated with the formation of strong recollimation MHD shocks after the collision of the collimated outflow with the isotropic wind termination surface. The spectra of electrons and protons up to PeV energies are simulated with a nonlinear Monte Carlo model of diffusive shock acceleration with turbulent magnetic field amplification. The overall efficiency of the jets power transfer to accelerated protons in this model is above 10\% and about 0.5\% for electrons above 50 TeV. The magnetic field amplification by Bell's instability due to the electric current of cosmic rays escaping the accelerator produces highly anisotropic magnetic turbulence in the shock downstream. This results in the polarized synchrotron X-ray emission with the photon electric vector predominantly transverse to the jet direction and the degree of polarization above 20\%. The model is able to reproduce the observed spectra and intensity profiles of non-thermal X-ray and gamma-ray emission, which are both dominated by the leptonic radiation.

Figures

Figures reproduced from arXiv: 2509.09883 by A.M. Bykov, E. Churazov, I. Khabibullin, S.M. Osipov, V.I. Romansky, Y.A. Uvarov.

Figure 1
Figure 1. Figure 1: FIG. 1. Schematic representation of the SS433+W50 system adopted here. The structures with bright non-thermal X-ray [PITH_FULL_IMAGE:figures/full_fig_p003_1.png] view at source ↗
Figure 2
Figure 2. Figure 2: FIG. 2. Morphology of the W50 nebula in simulations: a) [PITH_FULL_IMAGE:figures/full_fig_p004_2.png] view at source ↗
Figure 3
Figure 3. Figure 3: FIG. 3. Density, velocity, and entropy profiles in the MHD [PITH_FULL_IMAGE:figures/full_fig_p004_3.png] view at source ↗
Figure 4
Figure 4. Figure 4: FIG. 4. Simulated Monte Carlo spectra of accelerated par [PITH_FULL_IMAGE:figures/full_fig_p005_4.png] view at source ↗
Figure 5
Figure 5. Figure 5: FIG. 5. Profiles of RMS components of the magnetic field in [PITH_FULL_IMAGE:figures/full_fig_p006_5.png] view at source ↗
Figure 7
Figure 7. Figure 7: FIG. 7. Modeled spectrum of X-ray synchrotron radiation in [PITH_FULL_IMAGE:figures/full_fig_p007_7.png] view at source ↗
Figure 8
Figure 8. Figure 8: FIG. 8. Spatial profiles of synchrotron emission in e1 region [PITH_FULL_IMAGE:figures/full_fig_p008_8.png] view at source ↗
Figure 9
Figure 9. Figure 9: FIG. 9. Modeled spatial profile of synchrotron radiation in [PITH_FULL_IMAGE:figures/full_fig_p008_9.png] view at source ↗
Figure 11
Figure 11. Figure 11: FIG. 11. The upper panel shows polarization degree and [PITH_FULL_IMAGE:figures/full_fig_p009_11.png] view at source ↗
Figure 10
Figure 10. Figure 10: FIG. 10. The upper panel shows the downstream rms mag [PITH_FULL_IMAGE:figures/full_fig_p009_10.png] view at source ↗
Figure 12
Figure 12. Figure 12: FIG. 12. Modeled spectrum of the inverse Compton radiation [PITH_FULL_IMAGE:figures/full_fig_p009_12.png] view at source ↗

discussion (0)

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Reference graph

Works this paper leans on

78 extracted references · 46 linked inside Pith

  1. [1]

    Margon, Ann

    B. Margon, Ann. Rev. Astron. Astrophys.22, 507 (1984)

    1984

  2. [2]

    Fabrika, Sov

    S. Fabrika, Sov. Sci. Rev. Sect. E12, 1 (2004), astro- ph/0603390

    arXiv 2004

  3. [3]

    A. M. Cherepashchuk, A. V. Dodin, and K. A. Postnov, arXiv e-prints arXiv:2506.01106 (2025), 2506.01106

    arXiv 2025

  4. [4]

    Fabrika, Y

    S. Fabrika, Y. Ueda, A. Vinokurov, O. Sholukhova, and M. Shidatsu, Nature Physics11, 551 (2015), 1512.00435

    Pith/arXiv arXiv 2015

  5. [5]

    E. P. J. van den Heuvel, S. F. Portegies Zwart, and S. E. de Mink, MNRAS471, 4256 (2017), 1701.02355

    Pith/arXiv arXiv 2017

  6. [6]

    Cherepashchuk, A

    A. Cherepashchuk, A. Belinski, A. Dodin, and K. Post- 13 nov, New Astronomy103, 102060 (2023), 2305.07093

    Pith/arXiv arXiv 2023

  7. [7]

    M. C. Begelman, C. L. Sarazin, S. P. Hatchett, C. F. McKee, and J. Arons, ApJ238, 722 (1980)

    1980

  8. [8]

    Calvani and L

    M. Calvani and L. Nobili, Astroph. Space Sci.79, 387 (1981)

    1981

  9. [9]

    H. L. Marshall, C. R. Canizares, and N. S. Schulz, ApJ 564, 941 (2002), astro-ph/0108206

    Pith/arXiv arXiv 2002

  10. [10]

    Khabibullin, P

    I. Khabibullin, P. Medvedev, and S. Sazonov, MNRAS 455, 1414 (2016), 1510.05563

    Pith/arXiv arXiv 2016

  11. [11]

    K. M. Blundell, R. Laing, S. Lee, and A. Richards, ApJ Lett.867, L25 (2018), 1811.00760

    Pith/arXiv arXiv 2018

  12. [12]

    P. S. Medvedev, I. I. Khabibullin, and S. Y. Sazonov, Astronomy Letters45, 299 (2019), 2005.12416

    Pith/arXiv arXiv 2019

  13. [13]

    Waisberg, J

    I. Waisberg, J. Dexter, P. Olivier-Petrucci, G. Dubus, and K. Perraut, Astron. Astrophys.624, A127 (2019), 1811.12564

    Pith/arXiv arXiv 2019

  14. [14]

    R. M. Hjellming and K. J. Johnston, ApJ Lett.246, L141 (1981)

    1981

  15. [15]

    K. M. Blundell and M. G. Bowler, ApJ Lett.616, L159 (2004), astro-ph/0410456

    Pith/arXiv arXiv 2004

  16. [16]

    Migliari, R

    S. Migliari, R. P. Fender, K. M. Blundell, M. M´ endez, and M. van der Klis, MNRAS358, 860 (2005), astro- ph/0501097

    arXiv 2005

  17. [17]

    J. C. A. Miller-Jones, S. Migliari, R. P. Fender, T. W. J. Thompson, M. van der Klis, and M. M´ endez, ApJ682, 1141 (2008), 0804.1337

    Pith/arXiv arXiv 2008

  18. [18]

    W. J. Zealey, M. A. Dopita, and D. F. Malin, MNRAS 192, 731 (1980)

    1980

  19. [19]

    Eichler, ApJ272, 48 (1983)

    D. Eichler, ApJ272, 48 (1983)

    1983

  20. [20]

    Peter and D

    W. Peter and D. Eichler, ApJ417, 170 (1993)

    1993

  21. [21]

    P. F. Vel´ azquez and A. C. Raga, Astron. Astrophys.362, 780 (2000)

    2000

  22. [22]

    Zavala, P

    J. Zavala, P. F. Vel´ azquez, A. H. Cerqueira, and G. M. Dubner, MNRAS387, 839 (2008)

    2008

  23. [23]

    P. T. Goodall, F. Alouani-Bibi, and K. M. Blundell, MN- RAS414, 2838 (2011), 1101.3486

    Pith/arXiv arXiv 2011

  24. [24]

    Asahina, T

    Y. Asahina, T. Ogawa, T. Kawashima, N. Furukawa, R. Enokiya, H. Yamamoto, Y. Fukui, and R. Matsumoto, ApJ789, 79 (2014), 1407.2381

    Pith/arXiv arXiv 2014

  25. [25]

    Monceau-Baroux, O

    R. Monceau-Baroux, O. Porth, Z. Meliani, and R. Kep- pens, Astron. Astrophys.574, A143 (2015)

    2015

  26. [26]

    A. A. Panferov, Astron. Astrophys.599, A77 (2017), 1607.02043

    Pith/arXiv arXiv 2017

  27. [27]

    Ohmura, K

    T. Ohmura, K. Ono, H. Sakemi, Y. Tashima, R. Omae, and M. Machida, ApJ910, 149 (2021), 2102.06728

    Pith/arXiv arXiv 2021

  28. [28]

    G. M. Dubner, M. Holdaway, W. M. Goss, and I. F. Mirabel, Astron. J.116, 1842 (1998)

    1998

  29. [29]

    J. S. Farnes, B. M. Gaensler, C. Purcell, X. H. Sun, M. Haverkorn, E. Lenc, S. P. O’Sullivan, and T. Aka- hori, MNRAS467, 4777 (2017), 1604.06552

    Pith/arXiv arXiv 2017

  30. [30]

    J. W. Broderick, R. P. Fender, J. C. A. Miller-Jones, S. A. Trushkin, A. J. Stewart, G. E. Anderson, T. D. Staley, K. M. Blundell, M. Pietka, S. Markoff, et al., MNRAS 475, 5360 (2018), 1802.03406

    Pith/arXiv arXiv 2018

  31. [31]

    M. G. Watson, R. Willingale, J. E. Grindlay, and F. D. Seward, ApJ273, 688 (1983)

    1983

  32. [32]

    Yamauchi, N

    S. Yamauchi, N. Kawai, and T. Aoki, PASJ46, L109 (1994)

    1994

  33. [33]

    Safi-Harb and H

    S. Safi-Harb and H. ¨Ogelman, ApJ483, 868 (1997)

    1997

  34. [34]

    Safi-Harb and R

    S. Safi-Harb and R. Petre, ApJ512, 784 (1999)

    1999

  35. [35]

    Brinkmann, G

    W. Brinkmann, G. W. Pratt, S. Rohr, N. Kawai, and V. Burwitz, Astron. Astrophys.463, 611 (2007), astro- ph/0610781

    arXiv 2007

  36. [36]

    Safi-Harb, B

    S. Safi-Harb, B. Mac Intyre, S. Zhang, I. Pope, S. Zhang, N. Saffold, K. Mori, E. V. Gotthelf, F. Aharonian, M. Band, et al., ApJ935, 163 (2022), 2207.00573

    Pith/arXiv arXiv 2022

  37. [37]

    Kaaret, R

    P. Kaaret, R. Ferrazzoli, S. Silvestri, M. Negro, A. Man- freda, K. Wu, E. Costa, P. Soffitta, S. Safi-Harb, J. Poutanen, et al., ApJ Lett.961, L12 (2024), 2311.16313

    Pith/arXiv arXiv 2024

  38. [38]

    M. M. Reynoso, G. E. Romero, and H. R. Christiansen, MNRAS387, 1745 (2008), 0801.2903

    Pith/arXiv arXiv 2008

  39. [39]

    F. A. Aharonian and A. M. Atoyan, New Astron. Rev. 42, 579 (1998)

    1998

  40. [40]

    S. S. Kimura, K. Murase, and P. M´ esz´ aros, ApJ904, 188 (2020), 2008.04515

    Pith/arXiv arXiv 2020

  41. [41]

    Sudoh, Y

    T. Sudoh, Y. Inoue, and D. Khangulyan, ApJ889, 146 (2020), 1911.00013

    Pith/arXiv arXiv 2020

  42. [42]

    A. U. Abeysekara, A. Albert, R. Alfaro, C. Alvarez, J. D. ´Alvarez, R. Arceo, J. C. Arteaga-Vel´ azquez, D. Avila Ro- jas, H. A. Ayala Solares, E. Belmont-Moreno, et al., Na- ture562, 82 (2018)

    2018

  43. [43]

    H. E. S. S. Collaboration, F. Aharonian, F. Ait Benkhali, J. Aschersleben, H. Ashkar, M. Backes, V. Barbosa Mar- tins, R. Batzofin, Y. Becherini, D. Berge, et al., Science 383, 402 (2024), 2401.16019

    arXiv 2024

  44. [44]

    LHAASO Collaboration, arXiv e-prints arXiv:2410.08988 (2024), 2410.08988

    arXiv 2024

  45. [45]

    Churazov, I

    E. Churazov, I. Khabibullin, and R. Sunyaev, MNRAS 495, L51 (2020), 2002.02027

    Pith/arXiv arXiv 2020

  46. [46]

    E. M. Churazov, I. I. Khabibullin, and A. M. Bykov, Astron. Astrophys.688, A4 (2024), 2401.14770

    Pith/arXiv arXiv 2024

  47. [47]

    Mignone, G

    A. Mignone, G. Bodo, S. Massaglia, T. Matsakos, O. Tesileanu, C. Zanni, and A. Ferrari, Astrophys. J. Suppl. Ser.170, 228 (2007), astro-ph/0701854

    Pith/arXiv arXiv 2007

  48. [48]

    Heinz and R

    S. Heinz and R. Sunyaev, Astron. Astrophys.390, 751 (2002), astro-ph/0204183

    Pith/arXiv arXiv 2002

  49. [49]

    Bosch-Ramon, F

    V. Bosch-Ramon, F. A. Aharonian, and J. M. Paredes, Astron. Astrophys.432, 609 (2005), astro-ph/0411508

    Pith/arXiv arXiv 2005

  50. [50]

    G. E. Romero, M. Boettcher, S. Markoff, and F. Tavec- chio, Space Sci. Rev.207, 5 (2017), 1611.09507

    Pith/arXiv arXiv 2017

  51. [51]

    Peretti, M

    E. Peretti, M. Petropoulou, G. Vasilopoulos, and S. Gabici, Astron. Astrophys.698, A188 (2025), 2411.08762

    arXiv 2025

  52. [52]

    B. T. Zhang, S. S. Kimura, and K. Murase, arXiv e-prints arXiv:2506.20193 (2025), 2506.20193

    arXiv 2025

  53. [53]

    Carpio, A

    J. Carpio, A. Kheirandish, and B. Zhang, arXiv e-prints arXiv:2506.22550 (2025), 2506.22550

    arXiv 2025

  54. [54]

    J. Wang, B. Reville, and F. Aharonian, arXiv e-prints arXiv:2507.21048 (2025), 2507.21048

    Pith/arXiv arXiv 2025

  55. [55]

    Derouillat, A

    J. Derouillat, A. Beck, F. P´ erez, T. Vinci, M. Chiaramello, A. Grassi, M. Fl´ e, G. Bouchard, I. Plotnikov, N. Aunai, et al., Computer Physics Communications222, 351 (2018), 1702.05128

    Pith/arXiv arXiv 2018

  56. [56]

    J. M. Mart ´ ı, M. Perucho, J. L. G´ omez, and A. Fuentes, International Journal of Modern Physics D27, 1844011 (2018)

    2018

  57. [57]

    A. M. Bykov, D. C. Ellison, S. M. Osipov, and A. E. Vladimirov, ApJ789, 137 (2014), 1406.0084

    Pith/arXiv arXiv 2014

  58. [58]

    Bykov, V

    A. Bykov, V. Romansky, and S. Osipov, Universe8, 32 (2022), 2201.11791

    Pith/arXiv arXiv 2022

  59. [59]

    J. Park, D. Caprioli, and A. Spitkovsky, Phys. Rev. Lett. 114, 085003 (2015), 1412.0672

    Pith/arXiv arXiv 2015

  60. [60]

    Marcowith, A

    A. Marcowith, A. Bret, A. Bykov, M. E. Dieckman, L. O’C Drury, B. Lemb` ege, M. Lemoine, G. Morlino, G. Murphy, G. Pelletier, et al., Rep. on Progr. in Phys. 14 79, 046901 (2016), 1604.00318

    Pith/arXiv arXiv 2016

  61. [61]

    Gupta, D

    S. Gupta, D. Caprioli, and A. Spitkovsky, ApJ968, 17 (2024), 2312.13365

    Pith/arXiv arXiv 2024

  62. [62]

    Inoue, J

    T. Inoue, J. Shimoda, Y. Ohira, and R. Yamazaki, ApJ Lett.772, L20 (2013), 1305.4656

    Pith/arXiv arXiv 2013

  63. [63]

    V. N. Zirakashvili and V. S. Ptuskin, ApJ678, 939 (2008), 0801.4488

    Pith/arXiv arXiv 2008

  64. [64]

    Y. Hu, S. Xu, J. M. Stone, and A. Lazarian, ApJ941, 133 (2022), 2207.06941

    Pith/arXiv arXiv 2022

  65. [65]

    J. K. J. Hew and C. Federrath, MNRAS520, 6268 (2023), 2301.06033

    Pith/arXiv arXiv 2023

  66. [66]

    A. M. Bykov, S. M. Osipov, Y. A. Uvarov, D. C. El- lison, and P. Slane, Phys. Rev. D110, 023041 (2024), 2407.04160

    Pith/arXiv arXiv 2024

  67. [67]

    V. L. Ginzburg and S. I. Syrovatskii, Annual Review of Astronomy and Astrophysics3, 297 (1965)

    1965

  68. [68]

    Fabiani, E

    S. Fabiani, E. Costa, E. Del Monte, F. Muleri, P. Sof- fitta, A. Rubini, R. Bellazzini, A. Brez, L. de Ruvo, M. Minuti, et al., Astrophys. J. Suppl. Ser.212, 25 (2014), 1403.7200

    Pith/arXiv arXiv 2014

  69. [69]

    Abaroa, G

    L. Abaroa, G. E. Romero, G. C. Mancuso, and F. N. Rizzo, Astron. Astrophys.691, A93 (2024), 2409.16315

    Pith/arXiv arXiv 2024

  70. [70]

    Kayama, T

    K. Kayama, T. Tanaka, H. Uchida, T. G. Tsuru, Y. In- oue, D. Khangulyan, N. Tsuji, and H. Yamamoto, arXiv e-prints arXiv:2505.10620 (2025), 2505.10620

    Pith/arXiv arXiv 2025

  71. [71]

    F. J. Lockman, K. M. Blundell, and W. M. Goss, MN- RAS381, 881 (2007), 0707.0506

    Pith/arXiv arXiv 2007

  72. [72]

    A. W. Strong, I. V. Moskalenko, and V. S. Ptuskin, An- nual Review of Nuclear and Particle Science57, 285 (2007), astro-ph/0701517

    Pith/arXiv arXiv 2007

  73. [73]

    V. S. Ptuskin, V. N. Zirakashvili, and A. A. Plesser, Ad- vances in Space Research42, 486 (2008)

    2008

  74. [74]

    A. M. Bykov, A. Brandenburg, M. A. Malkov, and S. M. Osipov, Space Sci. Rev.178, 201 (2013), 1304.7081

    Pith/arXiv arXiv 2013

  75. [75]

    Marcowith, Frontiers in Astronomy and Space Sci- ences11, 1411076 (2025)

    A. Marcowith, Frontiers in Astronomy and Space Sci- ences11, 1411076 (2025)

    2025

  76. [76]

    J. F. McKenzie and H. J. Voelk, Astron. Astrophys.116, 191 (1982)

    1982

  77. [77]

    Murase and M

    K. Murase and M. Fukugita, Phys. Rev. D99, 063012 (2019), 1806.04194

    Pith/arXiv arXiv 2019

  78. [78]

    Abbasi, M

    R. Abbasi, M. Ackermann, J. Adams, S. K. Agarwalla, T. Aguado, J. A. Aguilar, M. Ahlers, J. M. Alameddine, N. M. Amin, K. Andeen, et al., ApJ981, 182 (2025), 2412.05046

    arXiv 2025