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Heat-flux Instabilities of Regularized Kappa Distributed Strahl Electrons Resolved with ALPS

T0 review · 1 major / 5 minor · reviewed 2026-08-06 · deepseek-v4-flash

Pith's one-line read Regularized Kappa strahl electrons grow firehose heat-flux instabilities at $\kappa<3/2$, a regime where standard Kappa models predict stability, with growth rates set by the exponential cutoff parameter $\alpha$.

desk verdict A solid numerical study with a new but unverified central claim: the κ<3/2 firehose heat-flux instability for RKD strahls needs an independent susceptibility check. read the letter →

arxiv 2507.03084 v1 pith:FTU2NRCY submitted 2025-07-03 physics.plasm-ph astro-ph.SRphysics.space-ph

classification physics.plasm-phastro-ph.SRphysics.space-ph PACS 52.35.-g
keywords regularizedkappadistributionstrahlelectronsheat-fluxinstabilityelectronfirehosewhistlersolarwindlinearkineticdispersionALPSsolver
verification ladder T0 review T1 audit T2 compute T3 formal

The pith

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

The reading

The paper asks how the solar-wind electron strahl, the main carrier of parallel heat flux, becomes unstable when its suprathermal tail is modeled with a regularized Kappa distribution rather than an idealized Maxwellian or a standard Kappa power law. Using the ALPS solver to evaluate the kinetic dispersion relation numerically, it resolves two parallel heat-flux instabilities, the whistler and the firehose, for a Maxwellian core plus drifting RKD strahl. The central result is that the firehose heat-flux instability can be unstable for $\kappa<3/2$ when the RKD cutoff is small, a regime in which standard Kappa models predict stability and where moments are not even defined. This matters because observed strahl distributions can show such hard suprathermal tails, so the choice of distribution shape changes whether heat flux is predicted to be self-regulated by instabilities.

What carries the argument

The central object is the regularized Kappa distribution, a kappa power-law tail multiplied by an exponential cutoff, with power-law index $\kappa$ and dimensionless cutoff parameter $\alpha$. The cutoff makes all velocity moments finite, so distributions with $\kappa<3/2$, inaccessible in the standard Kappa model because temperature would diverge, become physically admissible. The argument is carried by the ALPS solver, a numerical dispersion solver that evaluates plasma susceptibilities directly from arbitrary velocity distributions, which computes the complex frequencies $\omega(k)=\omega_r(k)+i\gamma(k)$ without requiring an analytic dielectric tensor for the RKD; the solver is validated against an independent code for standard Kappa and Maxwellian cases and against the RKD in the $\alpha=0$ limit.

What would settle it

An independent numerical integration of the same parallel dispersion relation for the FHFI case with $\kappa=1$ and $\alpha=0.1$ that fails to reproduce growth rates of order $\gamma/\Omega_e \approx 10^{-4}$ would refute the paper's central claim.

Watch

Extended reading notes

Core claim

The paper's central claim is that replacing the standard Kappa strahl with a regularized Kappa distribution qualitatively changes the linear stability of parallel heat-flux instabilities. For the whistler heat-flux instability, the RKD reproduces the standard Kappa result when the cutoff parameter $\alpha$ is zero and approaches the Maxwellian result as $\alpha$ grows, with growth rates ordered monotonically by $\alpha$ and enhanced for low $\kappa$. For the firehose heat-flux instability, the RKD predicts unstable modes for $\kappa<3/2$ (e.g., $\kappa=1$ with $\alpha=0.2$ or $\alpha=0.1$), whereas the standard Kappa model yields only stability in this regime. The paper further shows that Maxwellian models can overrate or underrate growth rates at different parameters, and that combined temperature-anisotropy plus heat-flux cases are similarly sensitive to the tail shape.

Load-bearing premise

The results for $\kappa<3/2$ depend on ALPS's numerical evaluation of the RKD plasma susceptibility being accurate at low $\kappa$ and small cutoff $\alpha$, a regime in which the solver was not independently cross-checked.

Editorial extensions

If this is right

  • For $\kappa<3/2$, the firehose heat-flux instability can grow, so heat-flux regulation by self-generated waves occurs in strahl regimes that standard Kappa models mark stable.
  • Growth rates increase as $\alpha$ decreases (stronger suprathermal tails), with $\alpha\to0$ recovering standard Kappa results and large $\alpha$ approaching Maxwellian behavior.
  • Maxwellian models can either overestimate or underestimate whistler and firehose growth rates depending on parameters, so distribution shape matters for predicting strahl stability.
  • RKD strahls with finite cutoff are now amenable to linear kinetic stability analysis without a closed-form dielectric tensor.
  • The same numerical setup can be extended to anisotropic cutoffs and to a three-component core-halo-strahl model, both flagged by the authors as next steps.

Reading between the lines

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

  • The paper leaves implicit that if the FHFI threshold extends to $\kappa<3/2$, strahl heat-flux regulation by firehose modes may operate in observed low-$\kappa$ events where standard Kappa models would say the strahl is stable.
  • A testable extension is a particle-in-cell simulation initialized with an RKD strahl at $\kappa=1$, $\alpha=0.1$; growth of parallel firehose modes would confirm the linear prediction and reveal the nonlinear saturation level.
  • The cutoff parameter $\alpha$ could be fitted to spacecraft electron distribution data, turning it into an observable that predicts whether whistler or firehose heat-flux instabilities dominate.
  • The same numerical machinery should map oblique propagation angles and anisotropic cutoffs, where competing temperature anisotropy and tail shape may shift thresholds further.
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Editorial analysis

A structured set of objections, weighed in public.

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

Referee Report

1 major / 5 minor

Summary. The paper studies linear kinetic instabilities driven by counterstreaming core and strahl electron populations in the solar wind, with the strahl modeled by a regularized Kappa distribution (RKD). Using the ALPS solver, the authors compute dispersion relations for parallel-propagating modes and obtain growth rates for whistler heat-flux, firehose heat-flux, and temperature-anisotropy instabilities. They validate ALPS against the DIS-K code for Maxwellian and standard Kappa (SKD) strahls, reproducing previous results by Shaaban et al. For RKD strahls, they find that growth rates depend sensitively on the cutoff parameter alpha and the spectral index kappa, converging to SKD at alpha = 0 and Maxwellian-like behavior for large alpha. The central new claim is that for the electron firehose heat-flux instability, RKDs with kappa < 3/2 (specifically kappa = 1, alpha = 0.1-0.2) support unstable modes, whereas SKDs in this regime are stable or unphysical.

Significance. If correct, the result that the exponential cutoff in the RKD qualitatively changes the linear stability of the strahl would be significant for solar wind modeling, since observed electron distributions often have kappa <= 3/2 and heat-flux regulation depends on the stability thresholds. The paper's validation against DIS-K for four instability types (WHFI, FHFI, WI, EFHI) is convincing and demonstrates the reliability of ALPS for SKD and Maxwellian distributions. The systematic parameter study of RKD effects is a useful contribution. However, the specific kappa < 3/2 FHFI result rests on ALPS's numerical evaluation of the non-analytic RKD susceptibility in a regime not covered by the validation, and therefore needs additional verification before it can be accepted.

major comments (1)
  1. [Section 4.2, Figure 9] The central result of the paper - that the RKD with kappa = 1 and alpha = 0.1 or 0.2 supports electron firehose heat-flux instabilities - rests entirely on ALPS's numerical solution of the dispersion relation for the non-analytic RKD in Eq. (4). The validations in Section 3 (against DIS-K) and Section 4.1 (RKD alpha = 0 limit) cover only Maxwellian/SKD distributions and the alpha = 0 limit, which reduces to the SKD; they do not test the numerical treatment of the exponential cutoff for small alpha. The reported growth rates in Figure 9 are of order gamma/Omega_e ~ 2 x 10^-4, which is comparable to typical quadrature and root-finding errors. The paper does not provide a grid-convergence study, a velocity-domain-size test, or any error estimate for the RKD susceptibility. I request an independent verification of the susceptibility for the kappa = 1, alpha = 0.1 case (e.g., a different numerical integration scheme or a cross-check with another dispersion solver) and a convergence study showing that the growth rate converges to a positive value. Without this, the existence of the kappa < 3/2 FHFI cannot be considered established.
minor comments (5)
  1. [Section 4.2, Figure 9 caption] The caption states that 'Increasing kappa while having a nonzero value for alpha leads to unstable solutions,' but the text and the plotted curves show that the unstable cases correspond to kappa = 1 (lower kappa) relative to kappa = 2; the caption appears to have the direction of the kappa-dependence reversed.
  2. [Section 4.1, Figure 6 caption] The caption says 'Increasing kappa amplifies the growth rates noticeably,' which contradicts the curves showing higher growth rates for kappa = 1 than for kappa = 2; the statement should presumably refer to decreasing kappa.
  3. [Table 1 and Section 4.3.2] The acronym for the electron firehose instability appears as both 'EFHI' (Table 1) and 'EHFI' (Sections 4.3.2 and Figure 13); please use one consistently.
  4. [Section 5] The sentence 'All cases for kappa <3/2 would not be accessible with an SKD model' is awkward and potentially misleading; consider rephrasing to 'Cases with kappa <3/2 are not accessible with an SKD model.'
  5. [Section 2] The reference to 'Appendix 5' should be simply 'the Appendix,' since the appendix is unnumbered.

Circularity Check

0 steps flagged · score 1.0 of 10

No significant circularity: the FHFI and WHFI growth rates are direct numerical solutions of the dispersion relation for the stated RKD model, with no fitted parameters or assumed unstable modes.

full rationale

The growth rates in Figures 2, 3, 6, 9, 12, and 13 are obtained by solving the ALPS dispersion relation det D = 0 (Appendix Eqs. 1-5) for the background velocity distribution specified in Eqs. (1)-(4). No parameter (κ or α) is fitted to the target growth rates, and no unstable mode is inserted by hand; the κ<3/2 FHFI result is an emergent numerical consequence of the stated distribution, not an input. Validation against DIS-K for SKD (Section 3) and the α=0 limit (Section 4.1) is a consistency check, not a circular reduction, because the target RKD case with α>0 and κ=1 is not used in that validation. Self-citations (e.g., Scherer et al. for the RKD definition and Schröder et al. 2025 for ALPS/RKD convergence) supply model and solver context, but they do not assert the FHFI result. The abstract's admission that analytical kinetic formalism for RKDs is 'still inaccessible' is a verification limitation, not circularity: it explains why the computation is numerical. No quoted equation reduces to its own input by construction, and no fitted quantity is renamed as a prediction. The central claim therefore has independent content; only minor self-citation, not load-bearing, appears in the paper.

Assumptions & free parameters 2 free parameters · 6 assumptions · 0 invented entities

The central result rests on the RKD model (Eq. 4), which is imported from prior work by the same group, and on the numerical accuracy of ALPS for the non-analytic RKD. The varied model parameters κ and α are chosen by hand and are not fitted to the target growth rates. No new physical entities are introduced.

free parameters (2)
  • kappa (κ) = varied: 1.0, 2.0, 3.0 (SKD)
    The power-law index of the strahl RKD is chosen by hand to sample different suprathermal tail strengths; the central claim that growth rates vary with tail shape depends on this parameter.
  • alpha (α) = varied: 0.0, 0.1, 0.2, 0.5
    The cutoff parameter controls the exponential decay of the RKD tail and is chosen by hand; the ordering of growth rates with α is a central result.
assumptions (6)
  • domain assumption The strahl electrons follow the drifting bi-regularized Kappa distribution of Eq. (4) with a single isotropic cutoff α and normalization W given by Eq. (5).
    The RKD is imported from prior work (Scherer et al.) to avoid superluminal particles and divergent moments; the paper does not derive it from microphysics.
  • standard math The linear Vlasov-Maxwell dispersion relation det D = 0 (Eq. 5 in the Appendix) correctly describes the waves and instabilities.
    This is the standard linear kinetic theory framework used in plasma physics.
  • domain assumption ALPS numerically evaluates the susceptibility integral (Eq. 1 in the Appendix) and performs the required analytic continuation in complex frequency for the non-analytic RKD.
    The solver's numerical accuracy for RKDs is not derived or independently verified in the paper, except in the α=0 limit.
  • domain assumption Protons are modeled as an isotropic Maxwellian and are dynamically negligible for the electron heat-flux instabilities.
    This follows prior studies (Shaaban et al.) and is stated in Section 3.
  • domain assumption Quasi-parallel propagation (k⊥≈0) is sufficient to capture the WHFI, FHFI, WI, and EFHI modes.
    The paper only solves for k⊥≈0 and cites prior studies for the validity of this reduction.
  • standard math The normalization constant W = U(3/2, (3-2κ)/2, α²κ) ensures finite moments for all κ>0.
    The Tricomi function normalization is taken from Scherer et al. (2019b) and used without proof.

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Cite this review

Pith. "Pith review of Heat-flux Instabilities of Regularized Kappa Distributed Strahl Electrons Resolved with ALPS." pith.science (2026). https://pith.science/paper/FTU2NRCY

@misc{pith2026250703084,
  author       = {Pith},
  title        = {Pith review of: Heat-flux Instabilities of Regularized Kappa Distributed Strahl Electrons Resolved with ALPS},
  year         = {2026},
  howpublished = {\url{https://pith.science/paper/FTU2NRCY}},
  note         = {Machine review of arXiv:2507.03084}
}
read the original abstract

The fluid behavior of the solar wind is affected by the heat flux carried by the suprathermal electron populations, especially the electron strahl (or beam) that propagates along the magnetic field. In turn, the electron strahl cannot be stable, and in the absence of collisions, its properties are regulated mainly by self-generated instabilities. This paper approaches the description of these heat-flux instabilities in a novel manner using regularized Kappa distributions (RKDs) to characterize the electron strahl. RKDs conform to the velocity distributions with suprathermal tails observed in situ, and at the same time allow for consistent macromodeling, based on their singularity-free moments. In contrast, the complexity of RKD models makes the analytical kinetic formalism complicated and still inaccessible, and therefore, here heat-flux instabilities are resolved using the advanced solver ALPS. Two primary types of instabilities emerge depending on plasma conditions: the whistler and firehose heat-flux instabilities. The solver is successfully tested for the first time for such instabilities by comparison with previous results for standard distributions, such as Maxwellian and Kappa. Moreover, the new RKD results show that idealized Maxwellian models can overrate or underestimate the effects of these instabilities, and also show differences from those obtained for the standard Kappa, which, for instance, underestimate the firehose heat-flux growth rates.

Figures

Figures reproduced from arXiv: 2507.03084 by the authors.

Figure 1
Figure 1. Plot of the VDF Core-Strahl model. The Maxwellian core is plotted with blue dots, the RKD Strahl is dashed red, and the combination is shown in solid black. The parameter κ is essential in determining the high-energy tails, and Γ is the Gamma function. The thermal speeds are defined as Θ∥,⊥ = q 2kBT κ ∥,⊥ /m with T κ ∥,⊥ = κ κ − 3/2 T M ∥,⊥ > T M ∥,⊥ (M. Lazar et al. 2015). The magnetohydrodynamic equations in fluid… view at source ↗
Figure 2
Figure 2. Comparison of ALPS and DIS-K for WHFI with different SKD strahl (blue: Maxwellian, black: SKD κ = 3, red: SKD κ = 2; solid: results derived with ALPS, dots: DIS-K results). All parameters are stated above the panels. 0.00 0.02 0.04 0.06 0.08 kc/ωpe −1 0 1 2 3 ω r / Ω e ×10 − 3 Maxwellian SKD κ = 3 SKD κ = 2 0.00 0.02 0.04 0.06 0.08 kc/ωpe −3 −2 −1 0 1 2 3 γ/ Ω e ×10 − 4 ALPS DIS-K FHFI, Ac = As = 1, βc = 1.2, βs = 0… view at source ↗
Figure 3
Figure 3. Comparison of ALPS and DIS-K for FHFI with different SKD strahl (blue: Maxwellian, black: SKD κ = 3, red: SKD κ = 2; solid: results derived with ALPS, dots: DIS-K results). All parameters are stated above the panels. 3.3. Temperature anisotropy + Heat flux While the whistler mode arises for a temperature excess in the direction perpendicular to the magnetic field, A = T⊥/T∥ > 1, at lower beam velocities, the firehos… view at source ↗
Figures from the paper (10 more)
Figure 4
Figure 4. Figure 4: Comparison of ALPS and DIS-K for WI+heat flux with different SKD strahl (blue: Maxwellian, black: SKD κ = 3, red: SKD κ = 2 ; solid: results derived with ALPS, dots: Dis-K results). All parameters are stated above the panels. 0.00 0.02 0.04 0.06 kc/ωpe 0 2 4 6 8 ω r / …
Figure 5
Figure 5. Figure 5: Comparison of ALPS and DIS-K for EFHI with different SKD strahl (blue: Maxwellian, black: SKD κ = 3, red: SKD κ = 2 ; solid: results derived with ALPS, dots: DIS-K results). All parameters are stated above the panels. Notice that the agreement between solvers is not on…
Figure 6
Figure 6. Figure 6: WHFI with different RKD strahl with reference to [PITH_FULL_IMAGE:figures/full_fig_p007_6.png]
Figure 7
Figure 7. Figure 7: Plot of the different VDFs with a counterstreaming strahl normalized to their maximum for the WHFI case corre￾sponding to [PITH_FULL_IMAGE:figures/full_fig_p008_7.png]
Figure 8
Figure 8. Figure 8: Contour plots of three different RKD core-strahl VDFs normalized to their maximum for the WHFI case. With ((κ = 2, α = 0.5); (κ = 2, α = 0.0); (κ = 1, α = 0.1)) from left to right. The anisotropy generated through the counterstreaming strahl is clearly visible. Note th…
Figure 9
Figure 9. Figure 9: FHFI with different RKD strahl with reference to [PITH_FULL_IMAGE:figures/full_fig_p009_9.png]
Figure 10
Figure 10. Figure 10: Plot of the different VDFs with a counterstreaming strahl normalized to their maximum for the FHFI case corre￾sponding to [PITH_FULL_IMAGE:figures/full_fig_p009_10.png]
Figure 11
Figure 11. Figure 11: Contour plots of three different RKD core-strahl VDFs normalized to their maximum for the FHFI case. With ((κ = 2, α = 0.5); (κ = 2, α = 0.0); (κ = 1, α = 0.1)) from left to right. The anisotropy generated through the counterstreaming strahl is clearly visible. Note t…
Figure 12
Figure 12. Figure 12: WI + Heat flux with different RKD strahl with reference to [PITH_FULL_IMAGE:figures/full_fig_p010_12.png]
Figure 13
Figure 13. Figure 13: EHFI with different RKD strahl with reference to [PITH_FULL_IMAGE:figures/full_fig_p011_13.png]

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Works this paper leans on

39 extracted references · 22 canonical work pages

  1. [1]

    , " * write output.state after.block = add.period write newline

    ENTRY address archivePrefix author booktitle chapter doi edition editor eprint howpublished institution journal key month number organization pages publisher school series title misctitle type volume year version url label extra.label sort.label short.list INTEGERS output.state before.all mid.sentence after.sentence after.block FUNCTION init.state.consts ...

  2. [2]

    write newline

    " write newline "" before.all 'output.state := FUNCTION format.url url empty "" new.block "" url * "" * if FUNCTION format.eprint eprint empty "" archivePrefix empty "" archivePrefix "arXiv" = new.block " " eprint * " " * new.block " " eprint * " " * if if if FUNCTION format.doi doi empty "" " " doi * " " * if FUNCTION format.pid doi empty eprint empty ur...

  3. [3]

    Clarifying the solar wind heat-flux instabilities

    thebibliography [1] 20pt to REFERENCES 6pt =0pt \@twocolumntrue 12pt -12pt 10pt plus 3pt =0pt =0pt =1pt plus 1pt =0pt =0pt -12pt =13pt plus 1pt =20pt =13pt plus 1pt \@M =10000 =-1.0em =0pt =0pt 0pt =0pt =1.0em @enumiv\@empty 10000 10000 `\.\@m \@noitemerr \@latex@warning Empty `thebibliography' environment \@ifnextchar \@reference \@latexerr Missing key o...

  4. [4]

    B., Owen , C

    Abraham , J. B., Owen , C. J., Verscharen , D., et al. 2022, title Radial Evolution of Thermal and Suprathermal Electron Populations in the Slow Solar Wind from 0.13 to 0.5 au: Parker Solar Probe Observations , , 931, 118, 10.3847/1538-4357/ac6605

  5. [5]

    Astfalk , P., G \"o rler , T., & Jenko , F. 2015, title DSHARK: A dispersion relation solver for obliquely propagating waves in bi-kappa-distributed plasmas , Journal of Geophysical Research (Space Physics), 120, 7107, 10.1002/2015JA021507

  6. [6]

    Astfalk, P., & Jenko, F. 2017, title LEOPARD: A grid-based dispersion relation solver for arbitrary gyrotropic distributions, Journal of Geophysical Research: Space Physics, 122, 89, https://doi.org/10.1002/2016JA023522

  7. [7]

    2019, title Scattering of strahl electrons in the solar wind between 0.3 and 1 au: Helios observations , , 486, 3404, 10.1093/mnras/stz1007

    Ber c i c , L., Maksimovi \'c , , M., Landi , S., & Matteini , L. 2019, title Scattering of strahl electrons in the solar wind between 0.3 and 1 au: Helios observations , , 486, 3404, 10.1093/mnras/stz1007

  8. [8]

    2024, title A dispersion function for the regularized kappa distribution function , Physics of Plasmas, 31, 072112, 10.1063/5.0212434

    Gaelzer , R., Fichtner , H., & Scherer , K. 2024, title A dispersion function for the regularized kappa distribution function , Physics of Plasmas, 31, 072112, 10.1063/5.0212434

Show all 39 references
  1. [9]

    Gaelzer, R., & Ziebell, L. F. 2016b, title Obliquely propagating electromagnetic waves in magnetized kappa plasmas, Physics of Plasmas, 23, 022110, 10.1063/1.4941260

  2. [10]

    F., & Meneses, A

    Gaelzer, R., Ziebell, L. F., & Meneses, A. R. 2016a, title The general dielectric tensor for bi-kappa magnetized plasmas, Physics of Plasmas, 23, 062108, 10.1063/1.4953430

  3. [11]

    A., Mason , G

    Gloeckler , G., Fisk , L. A., Mason , G. M., Roelof , E. C., & Stone , E. C. 2012, in American Institute of Physics Conference Series, Vol. 1436, Physics of the Heliosphere: A 10 Year Retrospective, ed. J. Heerikhuisen , G. Li , N. Pogorelov , & G. Zank , 136--143, 10.1063/1.4723601

  4. [12]

    2021, in Kappa Distributions; From Observational Evidences via Controversial Predictions to a Consistent Theory of Nonequilibrium Plasmas, ed

    Husidic , E., Lazar , M., Scherer , K., Fichtner , H., & Gaelzer , R. 2021, in Kappa Distributions; From Observational Evidences via Controversial Predictions to a Consistent Theory of Nonequilibrium Plasmas, ed. M. Lazar & H. Fichtner (Cham: Springer), 279--297, 10.1007/978-3...

  5. [13]

    H., López, R

    Kim, S., Schlickeiser, R., Yoon, P. H., López, R. A., & Lazar, M. 2017, title Spontaneous emission of electromagnetic fluctuations in Kappa magnetized plasmas, Plasma Physics and Controlled Fusion, 59, 125003, 10.1088/1361-6587/aa8898

  6. [14]

    G., Verscharen , D., Koskela , T., & Stansby , D

    Klein , K. G., Verscharen , D., Koskela , T., & Stansby , D. 2023, title danielver02/ALPS: Zenodo release, , v1.0.1 Zenodo, 10.5281/zenodo.8075682

  7. [15]

    2021, Astrophysics and Space Science Library, Vol

    Lazar , M., & Fichtner , H., eds. 2021, Astrophysics and Space Science Library, Vol. 464, Kappa Distributions; From Observational Evidences via Controversial Predictions to a Consistent Theory of Nonequilibrium Plasmas (Cham: Springer), 10.1007/978-3-030-82623-9

  8. [16]

    2016, title On the interpretation and applicability of tributions, Astronomy & Astrophysics, 589, A39, 10.1051/0004-6361/201527593

    Lazar , M., Fichtner , H., & Yoon , P. 2016, title On the interpretation and applicability of tributions, Astronomy & Astrophysics, 589, A39, 10.1051/0004-6361/201527593

  9. [17]

    2015, title Destabilizing effects of the supra-thermal populations in the solar wind , Astronomy & Astrophysics, 582, A124, 10.1051/0004-6361/201526509

    Lazar , M., Poedts , S., & Fichtner , H. 2015, title Destabilizing effects of the supra-thermal populations in the solar wind , Astronomy & Astrophysics, 582, A124, 10.1051/0004-6361/201526509

  10. [18]

    2020, title Toward a realistic macroscopic parametrization of space plasmas with regularized -distributions , , 634, A20, 10.1051/0004-6361/201936861

    Lazar , M., Scherer , K., Fichtner , H., & Pierrard , V. 2020, title Toward a realistic macroscopic parametrization of space plasmas with regularized -distributions , , 634, A20, 10.1051/0004-6361/201936861

  11. [19]

    Q., Dai , B., & Xue , T

    Liu , Y., Liu , S. Q., Dai , B., & Xue , T. L. 2014, title Dispersion and damping rates of dispersive Alfv \'e n wave in a nonextensive plasma , Physics of Plasmas, 21, 032125, 10.1063/1.4869243

  12. [20]

    L \'o pez, R. A. 2023, title ralopezh/dis-k: First Public Version, , v1.0.0 Zenodo, 10.5281/zenodo.8184896

  13. [21]

    A., Lazar , M., Shaaban , S

    L \'o pez , R. A., Lazar , M., Shaaban , S. M., Poedts , S., & Moya , P. S. 2020, title Alternative High-plasma Beta Regimes of Electron Heat-flux Instabilities in the Solar Wind , , 900, L25, 10.3847/2041-8213/abaf56

  14. [22]

    A., Moya, P

    L \'o pez, R. A., Moya, P. S., Shaaban, S. M., et al. 2021b, Advanced Numerical Tools for Studying Waves and Instabilities in Kappa Distributed Plasmas, ed. M. Lazar & H. Fichtner (Cham: Springer), 163--184, 10.1007/978-3-030-82623-9_9

  15. [23]

    A., Shaaban, S., & Lazar, M

    L \'o pez, R. A., Shaaban, S., & Lazar, M. 2021a, title General dispersion properties of magnetized plasmas with drifting bi-Kappa distributions. DIS-K: Dispersion Solver for Kappa Plasmas, Journal of Plasma Physics, 87, 905870310, 10.1017/S0022377821000593

  16. [24]

    N., López, R

    Micera, A., Zhukov, A. N., López, R. A., et al. 2020, title Particle-in-cell Simulation of Whistler Heat-flux Instabilities in the Solar Wind: Heat-flux Regulation and Electron Halo Formation, The Astrophysical Journal Letters, 903, L23, 10.3847/2041-8213/abc0e8

  17. [25]

    1968, Summary of Experimental Results from M.I.T

    Olbert, S. 1968, Summary of Experimental Results from M.I.T. Detector on IMP-1, Physics of the Magnetosphere Astrophysics and Space Science Library, Vol. 10:S 641-659 (Springer Netherlands), 641--659

  18. [26]

    J., & Lazar, M

    Scherer, K., Fichtner, H., Fahr, H. J., & Lazar, M. 2019a, title On the Applicability of κ-distributions, The Astrophysical Journal, 881, 93, 10.3847/1538-4357/ab2df9

  19. [27]

    2018, title Regularized -distributions with non-diverging moments, Europhysics Letters, 120, 50002, 10.1209/0295-5075/120/50002

    Scherer, K., Fichtner, H., & Lazar, M. 2018, title Regularized -distributions with non-diverging moments, Europhysics Letters, 120, 50002, 10.1209/0295-5075/120/50002

  20. [28]

    2019b, title Moments of the Anisotropic Regularized -distributions, Astrophys

    Scherer, K., Lazar, M., Husidic, E., & Fichtner, H. 2019b, title Moments of the Anisotropic Regularized -distributions, Astrophys. J., 880, 118, 10.3847/1538-4357/ab1ea1

  21. [29]

    L., Fichtner, H., Lazar, M., Verscharen, D., & Klein, K

    Schröder, D. L., Fichtner, H., Lazar, M., Verscharen, D., & Klein, K. G. 2025, title Temperature anisotropy instabilities of solar wind electrons with regularized kappa-halos resolved with ALPS, Physics of Plasmas, 32, 032109, 10.1063/5.0254526

  22. [30]

    M., Lazar , M., & Poedts , S

    Shaaban , S. M., Lazar , M., & Poedts , S. 2018a, title Clarifying the solar wind heat flux instabilities , , 480, 310, 10.1093/mnras/sty1567

  23. [31]

    M., Lazar, M., Yoon, P

    Shaaban , S. M., Lazar, M., Yoon, P. H., & Poedts, S. 2018b, title Beaming electromagnetic (or heat-flux) instabilities from the interplay with the electron temperature anisotropies, Physics of Plasmas, 25, 10.1063/1.5042481

  24. [32]

    M., Lazar, M., Yoon, P

    Shaaban, S. M., Lazar, M., Yoon, P. H., Poedts, S., & López, R. A. 2019, title Quasi-linear approach of the whistler heat-flux instability in the solar wind, Monthly Notices of the Royal Astronomical Society, 486, 4498–4507, 10.1093/mnras/stz830

  25. [33]

    Vasyliunas, V. M. 1968, title A survey of low-energy electrons in the evening sector of the magnetosphere with OGO 1 and OGO 3, Journal of Geophysical Research, 73, 2839. https://doi.org/10.1029/JA073i009p02839

  26. [34]

    Verscharen , D., Chandran , B. D. G., Jeong , S.-Y., et al. 2019, title Self-induced Scattering of Strahl Electrons in the Solar Wind , , 886, 136, 10.3847/1538-4357/ab4c30

  27. [35]

    G., Chandran, B

    Verscharen, D., Klein, K. G., Chandran, B. D. G., et al. 2018, title ALPS : the Arbitrary Linear Plasma Solver, Journal of Plasma Physics, 84, 10.1017/s0022377818000739

  28. [36]

    2008, title Electron temperature anisotropy constraints in the solar wind, Journal of Geophysical Research: Space Physics, 113, A03103, https://doi.org/10.1029/2007JA012733

    S tver\' a k, v., Tr\' a vn\' i c ek, P., Maksimovic, M., et al. 2008, title Electron temperature anisotropy constraints in the solar wind, Journal of Geophysical Research: Space Physics, 113, A03103, https://doi.org/10.1029/2007JA012733

  29. [37]

    B., Chen, L.-J., Wang, S., et al

    Wilson, L. B., Chen, L.-J., Wang, S., et al. 2019b, title Electron Energy Partition across Interplanetary Shocks. II. Statistics, The Astrophysical Journal Supplement Series, 245, 24, 10.3847/1538-4365/ab5445

  30. [38]

    B., Chen , L.-J., Wang , S., et al

    Wilson , III, L. B., Chen , L.-J., Wang , S., et al. 2019a, title Electron Energy Partition across Interplanetary Shocks. I. Methodology and Data Product , , 243, 8, 10.3847/1538-4365/ab22bd

  31. [39]

    F., & Moya, P

    Zenteno-Quinteros, B., Viñas, A. F., & Moya, P. S. 2021, title Skew-kappa Distribution Functions and Whistler Heat Flux Instability in the Solar Wind: The Core-strahlo Model, The Astrophysical Journal, 923, 180, 10.3847/1538-4357/ac2f9c

Pith tools

Reviewed August 6, 2026 · model on record in the stance chip above.