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Ripples spreading across the Galactic disc. Interplay of direct and indirect effects of the Sagittarius dwarf impact

T0 review · 4 major / 5 minor · reviewed 2026-08-10 · deepseek-v4-flash

Pith's one-line read A Sagittarius-like impact bends the Milky Way disc and then, through the spiral arms it induces, makes it breathe — dating the jolt to more than 400 million years ago.

desk verdict Strong simulation paper with a plausible new clock for dating the Sgr impact; the clock's transfer to the Milky Way is conditional on assumptions the authors honestly flag. read the letter →

arxiv 2501.12436 v2 pith:I2X4NS4I submitted 2025-01-21 astro-ph.GA

classification astro-ph.GA
keywords phasespiralbendingmodebreathingSagittariusdwarfgalaxyMilkyWaydiscN-bodysimulationGaiaarms
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

Gaia has found spiral patterns in the vertical position–velocity space of Milky Way stars, and those patterns come in one-arm and two-arm forms. This paper argues that both forms can be produced by a single Sagittarius-like satellite impact, in two stages with a measurable delay: the dwarf's gravity directly excites the disc's bending mode, and the two-arm spiral arms it tidally induces then excite the breathing mode. The bending mode decays quickly, the breathing mode persists, so the disc switches from bending-dominated to breathing-dominated, earliest in the inner galaxy. In the simulation, two-arm phase spirals appear about 200–250 million years after that switch. Applying this clock to Gaia implies the Milky Way disc was significantly perturbed more than about 400 million years ago.

What carries the argument

The central diagnostic is the separation of the disc's vertical velocity field into a bending part, $V_{\rm bend}=\frac{1}{2}[v_z(z)+v_z(-z)]$, and a breathing part, $V_{\rm breath}=\frac{1}{2}[v_z(z)-v_z(-z)]$, averaged over height. A Fourier decomposition in azimuth then separates the $m=1$ (bending) and $m=2$ (breathing) components and ties them to one-arm and two-arm phase spirals. The argument's clock is the horizontal-mixing damping timescale $\tau_D=R/\sigma_R$, which sets how quickly the bending mode fades after an impulsive satellite passage, together with the measured 200–250 Myr delay before two-arm phase spirals appear; that delay is what converts a mode-amplitude transition into a date for the Milky Way's perturbation.

What would settle it

Measure the winding age of Gaia's two-arm phase spirals and separately date the bending-to-breathing transition from the radial pattern of mode amplitudes: the paper's mechanism requires the spiral age to exceed the transition age by 200–250 Myr and requires the transition to happen earlier at smaller radii. If the two-arm spirals are no older than the transition, or if the transition is seen first in the outer disc, the central claim is contradicted.

Watch

Extended reading notes

Core claim

On its own terms, the central discovery is that the breathing mode of a galactic disc — the vertical oscillation in which material above and below the mid-plane moves in opposite directions — can be an indirect product of a satellite impact. In the five-billion-particle simulation of a Milky Way-like disc and a Sagittarius-like satellite, the satellite's direct gravitational pull excites the bending mode across the disc, while the same encounter tidally raises two-arm spiral arms. Those spiral arms, not the satellite itself, then drive the breathing mode, whose spectrogram tracks the pattern speeds of the bar and of the tidally induced arms rather than the satellite's orbit. The bending mode decays on the horizontal-mixing timescale $R/\sigma_R$, whereas the breathing mode persists as long as the arms do, so the disc transitions from bending-dominated to breathing-dominated, with the transition running from the inside out. Two-arm phase spirals appear 200–250 Myr after that transition, and applying this clock to Gaia implies the Milky Way disc was significantly perturbed more than about 400 Myr ago.

Load-bearing premise

The load-bearing premise is that the real Sagittarius dwarf was once much heavier and farther out, starting at roughly $5\times10^{10}$ solar masses on an apocentre near 130 kpc, because only such an earlier massive passage produces phase spirals as bright as Gaia's; if the real dwarf was lighter or on a different orbit, the more-than-400-million-year inference does not transfer to the Milky Way.

Editorial extensions

If this is right

  • The one-arm phase spiral seen in the solar neighbourhood is reproduced as a direct bending response to the satellite's passage, and the two-arm phase spirals seen at small guiding radii in Gaia appear naturally in the inner disc.
  • The breathing mode should not be read as a direct footprint of the satellite; it is excited by the tidally induced spiral arms, so phase-spiral analyses need to include self-gravity and spiral-armed discs.
  • A disc perturbed like the simulation should show a bending-to-breathing transition propagating from the inner to the outer galaxy on the $R/\sigma_R$ timescale, which can be compared with Gaia at different radii.
  • If the Gaia two-arm phase spirals are the same phenomenon, the Milky Way disc was perturbed more than about 400 million years ago, likely by an earlier, more massive Sagittarius dwarf.

Reading between the lines

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

  • A testable extension would be to measure the bending-to-breathing amplitude ratio as a function of radius in Gaia and check whether the transition front moves outward at roughly $R/\sigma_R$; if not, the clock is wrong.
  • If the real Sagittarius dwarf was never as massive as the simulation's initial satellite, the more-than-400-million-year date would not transfer to the Milky Way, and the same two-arm spirals would need an alternative driver such as bar buckling or repeated minor impacts.
  • The paper's own comparison with an isolated disc implies that the offset between the breathing-signal minimum and the arm peak (trailing for tidally induced arms, none for dynamic arms) could serve as a kinematic test to separate satellite-induced from internal spiral structure in other disc galaxies.
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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

4 major / 5 minor

Summary. This paper uses GPU-accelerated N-body simulations with roughly five billion particles to study how a Sagittarius-like dwarf galaxy perturbs a cold, self-gravitating Milky Way-like disc. The central dynamical claim is that the satellite directly excites the bending mode while simultaneously inducing two-arm spiral arms; those tidally induced arms subsequently excite the breathing mode, so that the breathing mode is an indirect consequence of the satellite interaction. The simulations show a bending-to-breathing dominance transition whose timescale follows roughly R/sigma_R, a longer-lived breathing mode, and the emergence of one-arm and two-arm phase spirals with a 200-250 Myr delay between the mode transition and the appearance of two-arm spirals. Applying this clock to Gaia data, the authors infer that the Milky Way disc was perturbed more than about 400 Myr ago, likely by Sagittarius. The final sections discuss the Sgr mass problem, the role of the LMC and multi-component disc effects, and the limitations of the model.

Significance. If the central mechanism is robust, this is an important step beyond earlier hot-disc simulations: the cold, self-gravitating disc allows internal and external drivers to interact, and the paper makes a specific, falsifiable prediction that two-arm phase spirals appear 200-250 Myr after the bending-to-breathing transition, with the delay shorter at smaller radii. The Fourier and spectral analyses are careful, the single-impact control run is a genuine strength, the comparison with an isolated galaxy model helps separate dynamic from tidally induced arms, and the simulation data are made available. The main caveat is that the Milky Way dating at the heart of the abstract and conclusions relies on a clock calibrated in a single encounter model and then transferred to the real Galaxy with additional assumptions; the model-internal dynamical results are much better supported than the MW-age inference.

major comments (4)
  1. [Section 6.1, Figs. 12-13] The claim that the MW disc was perturbed more than about 400 Myr ago rests on the 200-250 Myr interval between the bending-to-breathing transition and the appearance of two-arm phase spirals. This interval is read by eye from a single simulation with one Sgr initial mass (5x10^10 M_sun), one scale radius, and one apocentre (130 kpc); no parameter variation demonstrates that the delay is a robust clock rather than a property of that particular encounter strength, orbit, disc temperature, or bar slowdown rate. In addition, Section 6.1 substitutes the MW value sigma_R ~ 35 km/s at R=7 kpc for the transition timescale, but the final velocity dispersion of the simulated disc is not reported, so the transfer of the internal clock to the MW is not quantitatively established. I ask for a robustness study (varying satellite mass/orbit or disc temperature) or, failing that, for the MW-dating inference to be explicitly presented as illustrative rather than as a firm conclusion.
  2. [Section 6.2] The dating chain contains a tension that the paper acknowledges but does not resolve: at the epoch matching the present-day Sgr position (t=1.78 Gyr), the simulated phase spirals are much fainter than those observed by Gaia, so the observed MW spirals are attributed to an earlier, more massive Sgr passage. However, the 200-250 Myr delay used for the MW inference was calibrated on the first pericentre passage of the simulated dwarf, not on the earlier, heavier passage that is invoked to explain the Gaia data. The paper should either simulate that earlier passage directly or justify, with a concrete test, why the delay is independent of the passage strength and mass-loss history.
  3. [Sections 3.3, 4.2, 6.3] The central causal statement that tidally induced spiral arms excite the breathing mode (conclusion item 2) is inferred from the similarity of Fourier amplitudes and spectrograms and from a comparison with an isolated model. The single-impact control run removes the satellite after first apocentre but does not suppress the spiral arms, so it does not isolate the arm contribution to the breathing mode. A controlled experiment, for example an identical run with the tidally induced arms artificially suppressed or with an axisymmetric host potential, would make the causal claim conclusive. As written, the text should present the arm-driving mechanism as a well-motivated interpretation rather than a demonstrated result.
  4. [Section 5.3, Figs. 12-13] The timing of the first appearance of two-arm phase spirals is based on visual inspection of chronogram panels, with no quantitative metric such as the azimuthal Fourier amplitude of the z-v_z density contrast. Given that the claimed delay is only 50 Myr wide and is then used as a clock for the Milky Way, the classification of one-arm versus two-arm spirals and the first-appearance time should be made objective, with an uncertainty estimate.
minor comments (5)
  1. [Eq. (15) and Fig. 7] The quantity omega_k is defined with a factor 1/m, so it is effectively a pattern speed for the m-th Fourier component rather than the angular frequency of that component. Please clarify the notation in the text to avoid confusion, especially because the same Figure overplots Omega and nu, which are angular frequencies.
  2. [Fig. 3 and Fig. 6 captions] Several axis labels in Fig. 3 use placeholder symbols (e.g., '□50') where minus signs should appear, and the caption of Fig. 6 says 'as a faction of time' instead of 'as a function of time'. These rendering and typographical errors should be fixed in the final version.
  3. [Section 5.1] The citation 'GRA VITY Collaboration et al. 2022' has an unusual spacing and should be formatted consistently as 'GRAVITY Collaboration' in both text and references.
  4. [Section 2.2 and 6.2] The paper states that the dwarf's initial conditions are chosen so that t=1.78 Gyr matches the present-day Sgr, but it does not report the initial orbital energy or angular momentum with error bars. Since Section 6.2 later discusses how different orbital histories can reproduce the present-day Sgr, a brief quantification of the orbital match would help the reader assess the sensitivity of the encounter history.
  5. [Section 6.4] The paragraph on the gas disc ends with 'if we can include star formations in such simulations', which is grammatically awkward; please rephrase as 'if star formation can be included'.

Circularity Check

0 steps flagged · score 0.0 of 10

No circularity: the phase-spiral timing and mode-transition claims are forward simulation outputs, not re-statements of the fitted Sgr/MW initial conditions.

full rationale

The paper's central mechanism (direct satellite excitation of the bending mode, indirect excitation of the breathing mode by tidally induced spiral arms) and the 200-250 Myr delay between the bending-to-breathing transition and the emergence of two-arm phase spirals are extracted from a forward N-body simulation. The initial conditions (MWa disc of Fujii et al. 2019; Sgr-like dwarf with 5x10^10 Msun at 130 kpc apocentre) are matched to present-day Sgr observables and to the literature threshold for exciting phase spirals, but the two-arm-spiral delay and the R/sigma_R transition timescale are outputs of the simulation, not parameters fitted to the Gaia phase-spiral data. The MW dating in Section 6.1 uses the simulated delay together with observed R/sigma_R and the Rg<7 kpc locus of the observed two-arm spiral; this is a model-based inference rather than an inversion of a fit. The acknowledged limitations in Sections 6.2 and 6.4 (final-epoch phase spirals are fainter than Gaia's; no LMC, thick disc, or gas) genuinely weaken the transfer of the calibrated clock to the Milky Way and the attribution to Sgr, but they are robustness concerns, not circular reductions. The self-citations to the authors' prior MW model and isolated-galaxy comparison supply reproducible model inputs and controls, not an unverified uniqueness argument. No equation or fitted parameter is renamed as a prediction, so the derivation chain is self-contained.

Assumptions & free parameters 3 free parameters · 4 assumptions · 0 invented entities

The central claims rest on the fiducial MW host model (MWa of Fujii et al. 2019), the chosen initial Sgr mass and orbit, numerical resolution assumptions, and the transfer of the simulated R/sigma_R transition timescale to the real Milky Way.

free parameters (3)
  • Initial total mass of the Sgr-like dwarf = 5 x 10^10 solar masses
    Chosen because satellites must be heavier than roughly 3 x 10^10 solar masses to excite phase spirals (Section 6.2). The final mass is tuned to match the present-day Sgr, but the initial mass is not independently constrained.
  • Dwarf DM scale radius = 7.5 kpc
    Ad hoc choice in Section 2.1; the outer cutoff is set to the tidal radius at the initial position.
  • Initial apocentre of the dwarf orbit = 130 kpc
    Chosen so the dwarf reaches the observed Sgr position at t = 1.78 Gyr (Section 2.2); controls the number and timing of pericentre passages.
assumptions (4)
  • domain assumption The 5-billion-particle simulation with softening 0.01 kpc and shared timestep 0.61 Myr adequately resolves the vertical phase-space structures and mode amplitudes discussed.
    No convergence study is presented; resolution is asserted in Section 2.1.
  • domain assumption A single-component stellar thin disc dominates the disc's dynamical response, so omitting the thick disc, gas, and LMC does not change the qualitative conclusions.
    Authors justify in Section 6.4 by citing mass fractions and Stelea et al. (2024), but the LMC is known to affect the warp and possibly the Sgr orbit.
  • domain assumption The simulated R/sigma_R bending-to-breathing transition timescale is transferable to the real Milky Way disc.
    Used in Section 6.1 to convert the observed presence of two-arm phase spirals into a perturbation age of more than 400 Myr; only calibrated on one simulation.
  • domain assumption Axisymmetric potential approximation for computing guiding radius and angles is valid despite strong spiral arms.
    Appendix A.1 uses the Staeckel fudge in Agama; the authors note Debattista et al. (2025) warn of biases when spiral arms are strong.

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Cite this review

Pith. "Pith review of Ripples spreading across the Galactic disc. Interplay of direct and indirect effects of the Sagittarius dwarf impact." pith.science (2026). https://pith.science/paper/I2X4NS4I

@misc{pith2026250112436,
  author       = {Pith},
  title        = {Pith review of: Ripples spreading across the Galactic disc. Interplay of direct and indirect effects of the Sagittarius dwarf impact},
  year         = {2026},
  howpublished = {\url{https://pith.science/paper/I2X4NS4I}},
  note         = {Machine review of arXiv:2501.12436}
}
abstract

Gaia data have revealed vertically asymmetric phase-space structures in the Milky Way (MW) disc, such as phase spirals, indicating vertical oscillations. These oscillations exhibit two distinct modes: the bending mode and the breathing mode, associated with one-arm and two-arm phase spirals, respectively. This study aims to explore the excitation mechanisms of the bending and breathing modes and their subsequent evolution in the MW disc, focusing on the interplay between direct perturbations from the Sagittarius dwarf galaxy and indirect contributions from tidally induced spiral arms. We perform high-resolution $N$-body simulations to model the interaction between an MW-like disc galaxy and a Sagittarius dwarf-like satellite. These simulations resolve fine phase-space structures, enabling analysis of the bending and breathing modes at both macroscopic (global bending and breathing waves) and microscopic (local phase spirals) scales. Our simulations demonstrate that the satellite's perturbation directly excites the bending mode and induces spiral arms in the galactic disc. These spiral arms excite the breathing mode, making it an indirect consequence of the satellite interaction. Initially, the bending mode dominates, but it rapidly decays due to horizontal mixing. In contrast, the breathing mode persists for a longer duration, sustained by the spiral arms, leading to a transition from a bending-dominated to a breathing-dominated state. This transition progresses faster in the inner galaxy than in the outer regions. The simulations reproduce the one-arm phase spiral observed in the solar neighbourhood and reveal two-arm phase spirals, particularly in the inner galaxy, associated with spiral arm-induced breathing modes. Our findings highlight the combined effects of direct satellite perturbations and indirect spiral arm dynamics in shaping the vertical structure of the MW disc.

Figures

Figures reproduced from arXiv: 2501.12436 by the authors.

Figure 1
Figure 1. Upper panel: Position of the dwarf as a function of time. Blue solid, orange dashed, and green dotted lines show r = p x 2 + y 2 + z 2 , R = p x 2 + y 2 , and z, respectively. Lower panel: Mass of the dwarf as a function of time. Blue solid and orange dashed lines show the total mass and stellar mass enclosed within 5 kpc. The Green dotted line shows the stellar mass fraction. The red vertical line indicates the tim… view at source ↗
Figure 3
Figure 3. Face-on maps of the disc at t = 1.15 Gyr, which is ∼ 250 Myr after the first pericentre passage of the dwarf. Tidal forces from the dwarf induce prominent two-arm spiral arms and cause vertical corrugations (bending) and a breathing pattern in the galactic disc. The breathing pattern is aligned with the spiral arms. arm kinematic density wave (Kalnajs 1973). This wave develops into the two-arm spiral pattern due to … view at source ↗
Figure 4
Figure 4. Time evolution of the bending mode, breathing mode, and sur￾face density in the ring of R = 8–8.5 kpc. First panel: Total amplitudes of the bending (solid line) and breathing (dashed line) as functions of time. Second panel: Fourier amplitudes of the bending mode for m = 0, 1, 2, 3, and 4. Different line styles correspond to different Fourier com￾ponents as indicated in the legend. Third panel: Same as the second pa… view at source ↗
Figures from the paper (10 more)
Figure 5
Figure 5. Figure 5: Bending amplitude, breathing amplitude, and their ratio as func￾tions of time and galactocentric radius. First panel: Total amplitude of the bending mode. Second panel: Total amplitude of the breathing mode. Third panel: Amplitude ratio between the bending mode and the…
Figure 6
Figure 6. Figure 6: Evolution of the bending mode and the breathing mode in the single-impact model. First panel: Bending and breathing amplitude ra￾tio as a faction of time and the galactocentric radius. The horizontal axis indicates the time since the pericentre passage of the dwarf. A …
Figure 7
Figure 7. Figure 7: First panel: Spectrogram of the m = 1 bending mode. Lines indicate characteristic frequencies: Ω (solid), ±ν (dashed), Ω ± ν, and Ω ± 2ν (dotted). Second panel: Spectrogram of the m = 2 breathing mode. Solid and dashed lines indicate Ω and Ω ± κ/2, respectively. Third …
Figure 8
Figure 8. Figure 8: Maps of z-vz of the particles in the ‘solar neighbourhood’. The panels are colour-coded by number density (left column), density contrast (middle left column), radial velocity (middle right column), and azimuthal velocity (right column). The maps in the first row are a…
Figure 9
Figure 9. Figure 9: Grid in the R-ϕ space. The grid size is 1 kpc × 20◦ . The contour map shows the normalised surface density at t = 1.47 Gyr. are more tightly wound, reflecting the faster vertical winding rate in this region. No clear trends in azimuthal variation are evident from [PIT…
Figure 10
Figure 10. Figure 10: Variation of R-ϕ of the phase spiral in the snapshot at t = 1.47 Gyr. Each panel shows z/hz-vz/σz map for a set of particles grouped by R and ϕ. The maps are colour-coded by the density contrast, ∆ρ. Panels exhibiting one-arm phase spirals are painted in red tone, whi…
Figure 12
Figure 12. Figure 12: Time evolution of the phase spiral at R = 8 kpc. Columns represent azimuths equally spaced by 20◦ . Rows correspond to time, from t = 0.9 Gyr to 1.28 Gyr on the left block, and t = 1.29 Gyr to 1.67 Gyr on the right block. Each panel shows z/hz-vz/σz maps colour-coded …
Figure 13
Figure 13. Figure 13: Same as [PITH_FULL_IMAGE:figures/full_fig_p014_13.png]
Figure 14
Figure 14. Figure 14: Breathing signature around spiral arms. Upper panel: Breathing signature in the isolated model. Colour map shows the breathing veloc￾ity, vz,>0−vz,>0. Contours indicate the normalised density, Σ(R, ϕ)/Σ0(R). Black dots indicate the density peaks. Lower panel: Same as …
Figure 16
Figure 16. Figure 16: Two-arm phase spiral in the isolated model (left) and in the per￾turbed model (right). The two-arm phase spiral is fainter in the isolated model than in the perturbed model. tion. They also discussed the growth and disruption of the other arms based on the tentative s…

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Forward citations

Cited by 2 Pith papers

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

  1. Formation of the Two-Armed Phase Spiral from Multiple External Perturbations

    astro-ph.GA 2025-06 conditional novelty 6.0 of 10

    The two-armed phase spiral seen in Gaia's inner-disk stars is likely the overlap of two one-armed spirals created by two external perturbations separated by roughly 180 Myr.

  2. Influence of Bar Formation on Star Formation Segregation and Stellar Migration: Implications for Variations in the Age Distribution of Milky Way Disk Stars

    astro-ph.GA 2025-05 conditional novelty 5.0 of 10

    Bar formation in a simulated Milky Way analog drives inner stars outward and shifts star formation, producing a predicted peak in the outer disk's stellar age distribution at the bar formation epoch.

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Works this paper leans on

132 extracted references · 63 canonical work pages · cited by 2 Pith papers

  1. [1]

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

    ENTRY address archiveprefix author booktitle chapter edition editor howpublished institution eprint journal key month note number organization pages publisher school series title type volume year label extra.label sort.label short.list INTEGERS output.state before.all mid.sentence after.sentence after.block FUNCTION init.state.consts #0 'before.all := #1 ...

  2. [2]

    write newline

    " write newline "" before.all 'output.state := FUNCTION n.dashify 't := "" t empty not t #1 #1 substring "-" = t #1 #2 substring "--" = not "--" * t #2 global.max substring 't := t #1 #1 substring "-" = "-" * t #2 global.max substring 't := while if t #1 #1 substring * t #2 global.max substring 't := if while FUNCTION word.in bbl.in " " * FUNCTION format....

  3. [3]

    J., & Bensby , T

    Alinder , S., McMillan , P. J., & Bensby , T. 2023, , 678, A46

  4. [4]

    J., & Bensby , T

    Alinder , S., McMillan , P. J., & Bensby , T. 2024, , 690, A15

  5. [5]

    2018, , 561, 360

    Antoja , T., Helmi , A., Romero-G \'o mez , M., et al. 2018, , 561, 360

  6. [6]

    2023, , 673, A115

    Antoja , T., Ramos , P., Garc \' a-Conde , B., et al. 2023, , 673, A115

  7. [7]

    2022, , 668, A61

    Antoja , T., Ramos , P., L \'o pez-Guitart , F., et al. 2022, , 668, A61

  8. [8]

    Ard \`e vol , J., Mongui \'o , M., Figueras , F., Romero-G \'o mez , M., & Carrasco , J. M. 2023, , 678, A111

Show all 132 references
  1. [9]

    S., & Baba , J

    Asano , T., Kawata , D., Fujii , M. S., & Baba , J. 2024, , 529, L7

  2. [10]

    M., Lim , P

    Astropy Collaboration , Price-Whelan , A. M., Lim , P. L., et al. 2022, , 935, 167

  3. [11]

    M., Sip o cz , B

    Astropy Collaboration , Price-Whelan , A. M., Sip o cz , B. M., et al. 2018, , 156, 123

  4. [12]

    P., Tollerud , E

    Astropy Collaboration , Robitaille , T. P., Tollerud , E. J., et al. 2013, , 558, A33

  5. [13]

    R., & Wada , K

    Baba , J., Saitoh , T. R., & Wada , K. 2013, , 763, 46

  6. [14]

    C., & Weinberg , M

    Banik , U., van den Bosch , F. C., & Weinberg , M. D. 2023, , 952, 65

  7. [15]

    D., & van den Bosch , F

    Banik , U., Weinberg , M. D., & van den Bosch , F. C. 2022, , 935, 135

  8. [16]

    S., et al

    B \'e dorf , J., Gaburov , E., Fujii , M. S., et al. 2014, in Proceedings of the International Conference for High Performance Computing, 54--65

  9. [17]

    2012, Journal of Computational Physics, 231, 2825

    B \'e dorf , J., Gaburov , E., & Portegies Zwart , S. 2012, Journal of Computational Physics, 231, 2825

  10. [18]

    & Bovy , J

    Bennett , M. & Bovy , J. 2019, , 482, 1417

  11. [19]

    & Bovy , J

    Bennett , M. & Bovy , J. 2021, , 503, 376

  12. [20]

    Bennett , M., Bovy , J., & Hunt , J. A. S. 2022, , 927, 131

  13. [21]

    2012, , 426, 1324

    Binney , J. 2012, , 426, 1324

  14. [22]

    2024, , 535, 1898

    Binney , J. 2024, , 535, 1898

  15. [23]

    & Sch \"o nrich , R

    Binney , J. & Sch \"o nrich , R. 2018, , 481, 1501

  16. [24]

    & Tremaine , S

    Binney , J. & Tremaine , S. 2008, Galactic Dynamics: Second Edition

  17. [25]

    & Gerhard , O

    Bland-Hawthorn , J. & Gerhard , O. 2016, , 54, 529

  18. [26]

    2019, , 486, 1167

    Bland-Hawthorn , J., Sharma , S., Tepper-Garcia , T., et al. 2019, , 486, 1167

  19. [27]

    & Tepper-Garc \' a , T

    Bland-Hawthorn , J. & Tepper-Garc \' a , T. 2021, , 504, 3168

  20. [28]

    N., Smith , R., Fellhauer , M., et al

    Candlish , G. N., Smith , R., Fellhauer , M., et al. 2014, , 437, 3702

  21. [29]

    2024, , 975, 292

    Cao , C., Li , Z.-Y., Sch \"o nrich , R., & Antoja , T. 2024, , 975, 292

  22. [30]

    2019, , 490, 797

    Carrillo , I., Minchev , I., Steinmetz , M., et al. 2019, , 490, 797

  23. [31]

    R., et al

    Cheng , X., Anguiano , B., Majewski , S. R., et al. 2020, , 905, 49

  24. [32]

    Chequers , M. H. & Widrow , L. M. 2017, , 472, 2751

  25. [33]

    H., Widrow , L

    Chequers , M. H., Widrow , L. M., & Darling , K. 2018, , 480, 4244

  26. [34]

    2025, arXiv e-prints, arXiv:2503.20869

    Chiba , R., Frankel , N., & Hamilton , C. 2025, arXiv e-prints, arXiv:2503.20869

  27. [35]

    & Widrow , L

    Darling , K. & Widrow , L. M. 2019 a , , 490, 114

  28. [36]

    & Widrow , L

    Darling , K. & Widrow , L. M. 2019 b , , 484, 1050

  29. [37]

    Darragh-Ford , E., Hunt , J. A. S., Price-Whelan , A. M., & Johnston , K. V. 2023, , 955, 74

  30. [38]

    Debattista , V. P. 2014, , 443, L1

  31. [39]

    P., Khachaturyants , T., Amarante , J

    Debattista , V. P., Khachaturyants , T., Amarante , J. A. S., et al. 2025, , 537, 1620

  32. [40]

    2014, , 440, 2564

    Faure , C., Siebert , A., & Famaey , B. 2014, , 440, 2564

  33. [41]

    Frankel , N., Bovy , J., Tremaine , S., & Hogg , D. W. 2023, , 521, 5917

  34. [42]

    Friske , J. K. S. & Sch \"o nrich , R. 2019, , 490, 5414

  35. [43]

    S., B \'e dorf , J., Baba , J., & Portegies Zwart , S

    Fujii , M. S., B \'e dorf , J., Baba , J., & Portegies Zwart , S. 2019, , 482, 1983

  36. [44]

    Gaia Collaboration , Brown , A. G. A., Vallenari , A., et al. 2018 a , , 616, A1

  37. [45]

    2018 b , , 616, A11

    Gaia Collaboration , Katz , D., Antoja , T., et al. 2018 b , , 616, A11

  38. [46]

    Gaia Collaboration , Prusti , T., de Bruijne , J. H. J., et al. 2016, , 595, A1

  39. [47]

    Gaia Collaboration , Vallenari , A., Brown , A. G. A., et al. 2023, , 674, A1

  40. [48]

    S., Johnston , K

    Gandhi , S. S., Johnston , K. V., Hunt , J. A. S., et al. 2022, , 928, 80

  41. [49]

    2024, , 683, A47

    Garc \' a-Conde , B., Antoja , T., Roca-F \`a brega , S., et al. 2024, , 683, A47

  42. [50]

    2022, , 510, 154

    Garc \' a-Conde , B., Roca-F \`a brega , S., Antoja , T., Ramos , P., & Valenzuela , O. 2022, , 510, 154

  43. [51]

    P., & Khachaturyants , T

    Ghosh , S., Debattista , V. P., & Khachaturyants , T. 2022, , 511, 784

  44. [52]

    2025, , 980, 24

    Gilman , D., Bovy , J., Frankel , N., & Benson , A. 2025, , 980, 24

  45. [53]

    A., Minchev , I., O'Shea , B

    G \'o mez , F. A., Minchev , I., O'Shea , B. W., et al. 2013, , 429, 159

  46. [54]

    2023, scipy/scipy: SciPy 1.11.4

    Gommers, R., Virtanen, P., Haberland, M., et al. 2023, scipy/scipy: SciPy 1.11.4

  47. [55]

    Grand , R. J. J., Pakmor , R., Fragkoudi , F., et al. 2023, , 524, 801

  48. [56]

    2022, , 657, L12

    GRAVITY Collaboration , Abuter , R., Aimar , N., et al. 2022, , 657, L12

  49. [57]

    V., Poggio , E., et al

    Grion Filho , D., Johnston , K. V., Poggio , E., et al. 2021, , 507, 2825

  50. [58]

    2024, , 960, 133

    Guo , R., Li , Z.-Y., Shen , J., Mao , S., & Liu , C. 2024, , 960, 133

  51. [59]

    2019, , 879, L15

    Haines , T., D'Onghia , E., Famaey , B., Laporte , C., & Hernquist , L. 2019, , 879, L15

  52. [60]

    R., Millman, K

    Harris, C. R., Millman, K. J., van der Walt, S. J., et al. 2020, Nature, 585, 357

  53. [61]

    1990, , 356, 359

    Hernquist , L. 1990, , 356, 359

  54. [62]

    Hunt , J. A. S., Price-Whelan , A. M., Johnston , K. V., & Darragh-Ford , E. 2022, , 516, L7

  55. [63]

    Hunt , J. A. S., Stelea , I. A., Johnston , K. V., et al. 2021, , 508, 1459

  56. [64]

    Hunter , J. D. 2007, Computing in Science and Engineering, 9, 90

  57. [65]

    & Binney , J

    Jiang , I.-G. & Binney , J. 2000, , 314, 468

  58. [66]

    Kalnajs , A. J. 1973, , 2, 174

  59. [67]

    2018, , 479, L108

    Kawata , D., Baba , J., Ciuc a , I., et al. 2018, , 479, L108

  60. [68]

    P., Ghosh , S., Beraldo e Silva , L., & Daniel , K

    Khachaturyants , T., Debattista , V. P., Ghosh , S., Beraldo e Silva , L., & Daniel , K. J. 2022, , 517, L55

  61. [69]

    2019, , 489, 4962

    Khanna , S., Sharma , S., Tepper-Garcia , T., et al. 2019, , 489, 4962

  62. [70]

    2019, , 622, L6

    Khoperskov , S., Di Matteo , P., Gerhard , O., et al. 2019, , 622, L6

  63. [71]

    2016, in IOS Press, 87--90

    Kluyver , T., Ragan-Kelley , B., P \'e rez , F., et al. 2016, in IOS Press, 87--90

  64. [72]

    & Dubinski , J

    Kuijken , K. & Dubinski , J. 1995, , 277, 1341

  65. [73]

    Kumar , A., Das , M., & Kataria , S. K. 2021, , 506, 98

  66. [74]

    K., Das , M., & Debattista , V

    Kumar , A., Ghosh , S., Kataria , S. K., Das , M., & Debattista , V. P. 2022, , 516, 1114

  67. [75]

    Laporte , C. F. P., Johnston , K. V., G \'o mez , F. A., Garavito-Camargo , N., & Besla , G. 2018, , 481, 286

  68. [76]

    Laporte , C. F. P., Koposov , S. E., & Belokurov , V. 2022, , 510, L13

  69. [77]

    Laporte , C. F. P., Minchev , I., Johnston , K. V., & G \'o mez , F. A. 2019, , 485, 3134

  70. [78]

    2023, , 524, 6331

    Li , C., Siebert , A., Monari , G., Famaey , B., & Rozier , S. 2023, , 524, 6331

  71. [79]

    & Widrow , L

    Li , H. & Widrow , L. M. 2021, , 503, 1586

  72. [80]

    & Widrow , L

    Li , H. & Widrow , L. M. 2023, , 520, 3329

  73. [81]

    2021, , 911, 107

    Li , Z.-Y. 2021, , 911, 107

  74. [82]

    A., et al

    Lin , J., Guo , R., Bird , S. A., et al. 2024, , 528, 3281

  75. [83]

    F., et al

    L \'o pez-Corredoira , M., Garz \'o n , F., Wang , H. F., et al. 2020, , 634, A66

  76. [84]

    R., Skrutskie , M

    Majewski , S. R., Skrutskie , M. F., Weinberg , M. D., & Ostheimer , J. C. 2003, , 599, 1082

  77. [85]

    McMillan , P. J. 2017, , 465, 76

  78. [86]

    J., Petersson , J., Tepper-Garcia , T., et al

    McMillan , P. J., Petersson , J., Tepper-Garcia , T., et al. 2022, , 516, 4988

  79. [87]

    & Sellwood , J

    Merritt , D. & Sellwood , J. A. 1994, , 425, 551

  80. [88]

    2016 a , , 457, 2569

    Monari , G., Famaey , B., & Siebert , A. 2016 a , , 457, 2569

  81. [89]

    2016 b , , 461, 3835

    Monari , G., Famaey , B., Siebert , A., et al. 2016 b , , 461, 3835

  82. [90]

    & Sofue , Y

    Nakanishi , H. & Sofue , Y. 2016, , 68, 5

  83. [91]

    F., Frenk , C

    Navarro , J. F., Frenk , C. S., & White , S. D. M. 1997, , 490, 493

  84. [92]

    2024, pandas-dev/pandas: Pandas

    pandas development team, T. 2024, pandas-dev/pandas: Pandas

  85. [93]

    & Granger , B

    Perez , F. & Granger , B. E. 2007, Computing in Science and Engineering, 9, 21

  86. [94]

    R., Tasker , E

    Pettitt , A. R., Tasker , E. J., & Wadsley , J. W. 2016, , 458, 3990

  87. [95]

    2024, arXiv e-prints, arXiv:2407.18659

    Poggio , E., Khanna , S., Drimmel , R., et al. 2024, arXiv e-prints, arXiv:2407.18659

  88. [96]

    Poggio , E., Laporte , C. F. P., Johnston , K. V., et al. 2021, , 508, 541

  89. [97]

    P., Quinn , T

    Ro s kar , R., Debattista , V. P., Quinn , T. R., & Wadsley , J. 2012, , 426, 2089

  90. [98]

    J., & Cassisi , S

    Ruiz-Lara , T., Gallart , C., Bernard , E. J., & Cassisi , S. 2020, Nature Astronomy, 4, 965

  91. [99]

    & Dehnen , W

    Sch \"o nrich , R. & Dehnen , W. 2018, , 478, 3809

  92. [100]

    Sellwood , J. A. & Athanassoula , E. 1986, , 221, 195

  93. [101]

    Sellwood , J. A. & Merritt , D. 1994, , 425, 530

  94. [102]

    A., Hunt , J

    Stelea , I. A., Hunt , J. A. S., & Johnston , K. V. 2024, , 977, 252

  95. [103]

    L., & Hwang , J.-S

    Struck , C., Dobbs , C. L., & Hwang , J.-S. 2011, , 414, 2498

  96. [104]

    2022, , 515, 5951

    Tepper-Garc \' a , T., Bland-Hawthorn , J., & Freeman , K. 2022, , 515, 5951

  97. [105]

    2023, , 521, 114

    Tremaine , S., Frankel , N., & Bovy , J. 2023, , 521, 114

  98. [106]

    2019, , 482, 1525

    Vasiliev , E. 2019, , 482, 1525

  99. [107]

    & Belokurov , V

    Vasiliev , E. & Belokurov , V. 2020, , 497, 4162

  100. [108]

    2021, , 501, 2279

    Vasiliev , E., Belokurov , V., & Erkal , D. 2021, , 501, 2279

  101. [109]

    E., et al

    Virtanen , P., Gommers , R., Oliphant , T. E., et al. 2020, Nature Methods, 17, 261

  102. [110]

    2024, TomWagg/software-citation-station: v1.2

    Wagg, T., Broekgaarden, F., & Gültekin, K. 2024, TomWagg/software-citation-station: v1.2

  103. [111]

    & Broekgaarden , F

    Wagg , T. & Broekgaarden , F. S. 2024, arXiv e-prints, arXiv:2406.04405

  104. [112]

    B., et al

    Wang , C., Huang , Y., Yuan , H. B., et al. 2019, , 877, L7

  105. [113]

    L., & Deng , L

    Wang , H., L \'o pez-Corredoira , M., Carlin , J. L., & Deng , L. 2018 a , , 477, 2858

  106. [114]

    2022, , 940, L3

    Wang , H.-F., Hammer , F., Yang , Y.-B., & Wang , J.-L. 2022, , 940, L3

  107. [115]

    2018 b , , 478, 3367

    Wang , H.-F., Liu , C., Xu , Y., Wan , J.-C., & Deng , L. 2018 b , , 478, 3367

  108. [116]

    F., L \'o pez-Corredoira , M., Huang , Y., et al

    Wang , H. F., L \'o pez-Corredoira , M., Huang , Y., et al. 2020, , 491, 2104

  109. [117]

    2024, , 533, L31

    Wang , T., Chen , B.-Q., Lian , J.-H., Xiang , M.-S., & Liu , X.-W. 2024, , 533, L31

  110. [118]

    2010, in P roceedings of the 9th P ython in S cience C onference, ed

    W es M c K inney. 2010, in P roceedings of the 9th P ython in S cience C onference, ed. S t\'efan van der W alt & J arrod M illman, 56 -- 61

  111. [119]

    Widmark , A., Hunt , J. A. S., Laporte , C. F. P., & Monari , G. 2022 a , , 663, A16

  112. [120]

    Widmark , A., Laporte , C., & de Salas , P. F. 2021 a , , 650, A124

  113. [121]

    Widmark , A., Laporte , C. F. P., de Salas , P. F., & Monari , G. 2021 b , , 653, A86

  114. [122]

    Widmark , A., Laporte , C. F. P., & Monari , G. 2022 b , , 663, A15

  115. [123]

    M., & Naik , A

    Widmark , A., Widrow , L. M., & Naik , A. 2022 c , , 668, A95

  116. [124]

    Widrow , L. M. 2023, , 522, 477

  117. [125]

    M., Barber , J., Chequers , M

    Widrow , L. M., Barber , J., Chequers , M. H., & Cheng , E. 2014, , 440, 1971

  118. [126]

    Widrow , L. M. & Dubinski , J. 2005, , 631, 838

  119. [127]

    M., Gardner , S., Yanny , B., Dodelson , S., & Chen , H.-Y

    Widrow , L. M., Gardner , S., Yanny , B., Dodelson , S., & Chen , H.-Y. 2012, , 750, L41

  120. [128]

    M., Pym , B., & Dubinski , J

    Widrow , L. M., Pym , B., & Dubinski , J. 2008, , 679, 1239

  121. [129]

    Williams , M. E. K., Steinmetz , M., Binney , J., et al. 2013, , 436, 101

  122. [130]

    2023, , 956, 13

    Xu , Y., Liu , C., Li , Z., et al. 2023, , 956, 13

  123. [131]

    2020, , 905, 6

    Xu , Y., Liu , C., Tian , H., et al. 2020, , 905, 6

  124. [132]

    J., Carlin , J

    Xu , Y., Newberg , H. J., Carlin , J. L., et al. 2015, , 801, 105

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