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arxiv: 2603.05287 · v3 · submitted 2026-03-05 · 🌌 astro-ph.GA

Recognition: 2 theorem links

· Lean Theorem

The Local Tremaine-Weinberg Method for Galactic Pattern Speed: Theory and its Application to IllustrisTNG

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Pith reviewed 2026-05-15 16:34 UTC · model grok-4.3

classification 🌌 astro-ph.GA
keywords pattern speedTremaine-Weinberg methodgalactic barsgalactic spiralsIllustrisTNGcontinuity equationgalactic dynamics
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The pith

An integral of the continuity equation over any closed loop defines local galactic pattern speeds

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

The paper derives an integral form of the continuity equation over arbitrary closed loops in a galactic disk to define a local pattern speed for any chosen region. This formalism recovers all standard Tremaine-Weinberg variants as special cases when the loop takes particular shapes. Applied to TNG50 simulations of face-on barred galaxies and mock Milky Way configurations, it recovers both constant global speeds and radially varying profiles while distinguishing solid-body bars from spirals. A reader cares because it removes the need for rigid geometric assumptions when measuring how bars and spirals rotate.

Core claim

Integrating the continuity equation over arbitrary closed loops yields a local pattern speed that accurately recovers both constant global values for bars and radially varying profiles for spirals in TNG50 test galaxies, naturally differentiating coherent solid-body rotators from differential spirals.

What carries the argument

The integral form of the continuity equation over arbitrary closed loops, which defines the local pattern speed for the enclosed galactic region.

If this is right

  • Standard TW methods emerge exactly when the integration loop is restricted to straight lines or other conventional contours.
  • The approach measures both constant pattern speeds in bars and radially varying speeds in spirals within TNG50 face-on and mock Milky Way galaxies.
  • Coherent bars appear as solid-body rotators while spirals exhibit differential rotation without imposed geometric approximations.
  • The framework extends directly to any non-axisymmetric structure by choosing appropriate closed loops.

Where Pith is reading between the lines

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

  • The same loop integrals could be applied to observed surface-density maps to extract local pattern speeds from real telescope data.
  • Repeated application over simulation time steps would track how local speeds change as bars slow or spirals wind.
  • Inclusion of gas or star-formation tracers in the continuity integral could link pattern speeds to observable star-formation patterns.

Load-bearing premise

That integrating the continuity equation over arbitrary closed loops directly yields accurate local pattern speeds without significant biases from projection, noise, or non-steady flows.

What would settle it

A direct comparison showing mismatch between the local pattern speed computed from the integral method and the true pattern speed measured by tracking density feature rotation in the same simulation snapshot.

Figures

Figures reproduced from arXiv: 2603.05287 by Hangci Du, Junqiang Ge, Rui Guo, Yougang Wang.

Figure 1
Figure 1. Figure 1: Direct geometric interpretation of the local pattern speed. A coherent galactic pattern rotates around the origin with angular velocity Ωp. We verify the mass balance within a small annular sector (bounded by red or black lines). During a time interval δt, the pattern rotates from the black sector (A1 ∪ A2) to the red sector (A2 ∪ A3). Provided that the tracer particles are neither created nor destroyed, t… view at source ↗
Figure 2
Figure 2. Figure 2: A unified view of the local pattern speed measurement based on the continuity equation, generalized from [PITH_FULL_IMAGE:figures/full_fig_p005_2.png] view at source ↗
Figure 3
Figure 3. Figure 3: Schematic illustrating the application of the local pattern speed framework to a region harboring multiple, radially varying pattern speeds. The annular sector, bounded by the solid red lines, is conceptually subdivided into a series of thinner annuli (separated by dotted red lines), with each sub-annulus n assumed to host a pattern rotating with a distinct local speed Ωp(rn). As derived in Section 2.5, ap… view at source ↗
Figure 4
Figure 4. Figure 4: Local pattern speed analysis for three distinct TNG50 barred galaxies. Each panel corresponds to a specific galaxy: (a) a barred galaxy with grand-design spiral arms, (b) a classic bar with no significant outer structures, and (c) a failed candidate for an ultrafast bar. The layout follows [PITH_FULL_IMAGE:figures/full_fig_p009_4.png] view at source ↗
Figure 5
Figure 5. Figure 5: Local pattern speed analysis for three non-barred spiral galaxies in TNG50, illustrating three distinct dynamical regimes. The layout is identical to [PITH_FULL_IMAGE:figures/full_fig_p011_5.png] view at source ↗
Figure 6
Figure 6. Figure 6: Local pattern speed analysis illustrating the method’s capability to diagnose complex dynamical states. The layout mirrors [PITH_FULL_IMAGE:figures/full_fig_p013_6.png] view at source ↗
Figure 7
Figure 7. Figure 7: Schematic of the closed integration loop used to derive the classic Tremaine-Weinberg (TW) method from our general integral formalism. The path ∂S (red line) consists of a straight segment along the galaxy’s major axis (x-axis) and a large semicircular arc. The arrows along the straight segment represent the component of the velocity perpendicular to the integration path, vy, which corresponds to the negat… view at source ↗
Figure 8
Figure 8. Figure 8: Geometric schematic for deriving the J. L. Sanders et al. (2019) method for the Milky Way bar from our general framework, viewed from the North Galactic Pole. The integration surface ∂V is a semi-cylinder, whose flat cross-section (the straight red line) passes through the Sun and is oriented at an angle ℓ relative to the GC-Sun line. The red semi-circle curve represents the cylindrical wall at infinity. W… view at source ↗
Figure 9
Figure 9. Figure 9: Geometric schematic for a proposed method to measure the pattern speeds of local spiral arms, viewed from the North Galactic Pole. The integration surface ∂V is a sphere of radius s centered on the Sun. The outward normal vector nˆ at any point on the sphere is, by definition, the unit vector along the line of sight. Therefore, the physical flux term in our formalism, ρ(v·nˆ), directly corresponds to the f… view at source ↗
Figure 10
Figure 10. Figure 10: Geometric comparison between the traditional radial TW formulation and the exact flux balance required by the continuity equation. Left panel: The geometry near the galaxy center (small projected distance y0). Right panel: The geometry at a larger projected distance (large y0), where the deviation becomes significant. In both panels, the cyan curve represents the theoretical inner boundary of the integrat… view at source ↗
Figure 11
Figure 11. Figure 11: Schematic of the geometry for geometrically exact formulation radial TW method of a single slit when m = 0. The integration loop (solid red line) consists of a straight line segment at y = y0, analogous to an observational slit, and a closing semicircle at a large radius rN → ∞. The enclosed area is subdivided by N concentric circles (dotted red lines) at radii rn with all their centers at the origin, def… view at source ↗
Figure 12
Figure 12. Figure 12: Visualization of the matrix elements for the linear system KΩ = W (Eq. C34). We use multiple slits (m = 1, 2, 3, . . .) positioned at different projected heights ym to probe a disk subdivided into concentric radial annuli (n = 1, 2, . . .). The matrix element Kmn (represented by the colored line segments) is the luminosity-weighted moment integral R Σx dx calculated along the portions of the m-th slit tha… view at source ↗
Figure 13
Figure 13. Figure 13: An example of local pattern speed on TNG50-1 galaxy ID 585282. Left Panel: Face-on stellar surface density map. The analysis region extends to R = 15.0 kpc (cyan circle). The bar is aligned along the X-axis, with its length indicated by the black dashed line (Rbar ≈ 2.2 kpc). Right Panels: Radial analysis of the pattern speed and structural modes. Top Subplot: The blue solid line with markers represents t… view at source ↗
Figure 14
Figure 14. Figure 14: Validation of the 3D pattern speed measurement using a TNG50 Milky Way analogue. Left panel (a): Face-on density map rotated to a bar angle of ϕbar = 27◦ . The “Sun” is located at X = −8.1 kpc (black circle). Four thin dashed lines extending from the Sun indicate the lines of sight for Galactic longitudes ℓ = ±10◦ and ℓ = ±20◦ . The thick black dashed line marks the extent and orientation of the stellar b… view at source ↗
read the original abstract

The Tremaine-Weinberg (TW) method and its variations provide the most direct means to measure the pattern speeds of galactic bars. We establish a unifying framework by deriving an integral form of the continuity equation over an arbitrary closed loop. This naturally defines a local pattern speed for any chosen region in a galactic disk (including bars and spirals). We demonstrate that this intuitive formalism recovers all standard variants of the TW method as special cases corresponding to specific choices of the integration loop. In this paper, we validate this framework and demonstrate its diagnostic power. By applying it to a diverse set of test cases from the TNG50 simulation, including face-on prototype barred galaxies and highly constrained Mock Milky Way standard configurations, we show that this formalism accurately recovers both constant global pattern speeds and radially varying profiles. Rather than relying on rigid geometric approximations, our method naturally differentiates coherent solid-body rotators (bars) from spirals. Our results validate that this unified integral framework provides a robust, geometrically flexible, and practically extensible tool for decoding complex dynamics of galactic structures.

Editorial analysis

A structured set of objections, weighed in public.

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

Referee Report

2 major / 2 minor

Summary. The paper derives a local Tremaine-Weinberg method by integrating the 2D continuity equation over arbitrary closed loops to define a local pattern speed Ω_p for any region in a galactic disk. It shows that standard TW variants emerge as special cases for particular loop choices, and validates the approach on TNG50 simulations of face-on barred galaxies and mock Milky Way configurations, recovering both constant global pattern speeds and radially varying profiles while distinguishing solid-body bars from spirals.

Significance. If the central claim holds after addressing potential biases, the framework offers a geometrically flexible extension of the TW method that avoids rigid assumptions and can differentiate coherent rotators from spirals in both simulations and observations. The TNG50 tests on diverse cases provide initial support for its diagnostic utility in decoding complex galactic dynamics.

major comments (2)
  1. [Abstract and validation on TNG50] Abstract and validation description: the claim that the method accurately recovers expected pattern speeds in TNG50 test cases is not supported by reported quantification of continuity-equation residuals arising from star-formation sinks, supernova feedback, numerical diffusion, and finite particle sampling; these source terms violate the exact continuity assumption underlying the integral form ∮ (Σ v · dl) / ∮ (Σ x_perp dl) = Ω_p and could systematically bias the recovered Ω_p(r) profiles or the bar-versus-spiral distinction.
  2. [Theory section (integral form derivation)] Theory derivation: the integral framework assumes the continuity equation holds without source terms over the chosen closed loop, yet the manuscript does not derive or test correction terms for non-steady flows or discreteness effects present in IllustrisTNG snapshots; this assumption is load-bearing for the claim that the method yields unbiased local pattern speeds.
minor comments (2)
  1. [Application to mock Milky Way] Clarify the precise criteria used to select closed loops in the highly constrained mock Milky Way configurations and how projection effects are mitigated.
  2. [Results figures] Include explicit error bars or residual maps for the recovered Ω_p(r) in the TNG50 figures to allow assessment of precision.

Simulated Author's Rebuttal

2 responses · 0 unresolved

We thank the referee for their constructive comments, which highlight important aspects of the continuity assumption and validation. We address each major comment below and will revise the manuscript accordingly to strengthen the presentation.

read point-by-point responses
  1. Referee: [Abstract and validation on TNG50] Abstract and validation description: the claim that the method accurately recovers expected pattern speeds in TNG50 test cases is not supported by reported quantification of continuity-equation residuals arising from star-formation sinks, supernova feedback, numerical diffusion, and finite particle sampling; these source terms violate the exact continuity assumption underlying the integral form ∮ (Σ v · dl) / ∮ (Σ x_perp dl) = Ω_p and could systematically bias the recovered Ω_p(r) profiles or the bar-versus-spiral distinction.

    Authors: We agree that explicit quantification of residuals would strengthen the validation claims. While the TNG50 tests recover known pattern speeds from independent methods, the manuscript does not report the magnitude of source terms. In the revised manuscript we will add a dedicated analysis section (with new figure) that computes the integrated continuity residuals for the selected galaxies, estimates their contribution relative to the measured integrals, and discusses any resulting bias on Ω_p(r) and the bar/spiral distinction. revision: yes

  2. Referee: [Theory section (integral form derivation)] Theory derivation: the integral framework assumes the continuity equation holds without source terms over the chosen closed loop, yet the manuscript does not derive or test correction terms for non-steady flows or discreteness effects present in IllustrisTNG snapshots; this assumption is load-bearing for the claim that the method yields unbiased local pattern speeds.

    Authors: The integral form follows directly from integrating the source-free continuity equation, recovering the standard TW method as a special case. In TNG50 the assumption is necessarily approximate; our empirical recovery of expected pattern speeds indicates the net effect of sources and discreteness is small for the chosen loops. Deriving general analytic corrections for arbitrary source terms is not straightforward and lies outside the scope of the present work. We will nevertheless revise the theory section to include an explicit discussion of the assumption, provide order-of-magnitude estimates of discreteness and non-steady contributions from the simulation data, and add sensitivity tests that vary loop size and smoothing scale. revision: partial

Circularity Check

0 steps flagged

No circularity: derivation rests on standard continuity equation

full rationale

The paper starts from the continuity equation, integrates it over arbitrary closed loops to define local pattern speed, and shows that existing TW variants emerge as special cases for particular loop choices. This is a direct mathematical consequence of the continuity equation itself rather than a fit, self-citation chain, or redefinition of inputs. No load-bearing step reduces to a parameter fitted from the target result, and the TNG50 applications are presented as validation tests rather than part of the derivation. The framework is therefore self-contained against external benchmarks.

Axiom & Free-Parameter Ledger

0 free parameters · 1 axioms · 0 invented entities

Review based on abstract only; full paper text unavailable so ledger is provisional. The derivation rests on the continuity equation as the starting point.

axioms (1)
  • domain assumption The continuity equation holds for the surface density and velocity field in the galactic disk
    Invoked to derive the integral form over closed loops.

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Works this paper leans on

49 extracted references · 49 canonical work pages · 2 internal anchors

  1. [1]

    Aguerri, J. A. L., Méndez-Abreu, J., Falcón-Barroso, J., et al. 2015, A&A, 576, A102, doi: 10.1051/0004-6361/201423383

  2. [2]

    E., et al

    Ansar, S., Pearson, S., Sanderson, R. E., et al. 2025, ApJ, 978, 37, doi: 10.3847/1538-4357/ad8b45

  3. [3]

    1980, A&A, 88, 184

    Athanassoula, E. 1980, A&A, 88, 184

  4. [4]

    1992, MNRAS, 259, 345, doi: 10.1093/mnras/259.2.345

    Athanassoula, E. 1992, MNRAS, 259, 345, doi: 10.1093/mnras/259.2.345

  5. [5]

    S., Aldering , G., et al

    Athanassoula, E. 2003, MNRAS, 341, 1179, doi: 10.1046/j.1365-8711.2003.06473.x

  6. [6]

    2023, ApJ, 953, 173, doi: 10.3847/1538-4357/ace2b9

    Beane, A., Hernquist, L., D’Onghia, E., et al. 2023, ApJ, 953, 173, doi: 10.3847/1538-4357/ace2b9

  7. [7]

    2008, Galactic Dynamics: Second Edition

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

  8. [8]

    G., Sormani, M

    Borodina, O., Williams, T. G., Sormani, M. C., Meidt, S., & Schinnerer, E. 2023, MNRAS, 524, 3437, doi: 10.1093/mnras/stad2068

  9. [9]

    1980, A&A, 81, 198

    Contopoulos, G. 1980, A&A, 81, 198

  10. [10]

    Cuomo, V., Aguerri, J. A. L., Corsini, E. M., & Debattista, V. P. 2020, A&A, 641, A111, doi: 10.1051/0004-6361/202037945

  11. [11]

    H., Buttitta, C., et al

    Cuomo, V., Lee, Y. H., Buttitta, C., et al. 2021, A&A, 649, A30, doi: 10.1051/0004-6361/202040261

  12. [12]

    A., Corsini, E

    Cuomo, V., Lopez Aguerri, J. A., Corsini, E. M., et al. 2019, A&A, 632, A51, doi: 10.1051/0004-6361/201936415 de Araujo Ferreira, P., Napolitano, N. R., Casarini, L., et al. 2025, MNRAS, 539, 2855, doi: 10.1093/mnras/staf646

  13. [13]

    , keywords =

    Debattista, V. P., Gerhard, O., & Sevenster, M. N. 2002, MNRAS, 334, 355, doi: 10.1046/j.1365-8711.2002.05500.x

  14. [14]

    P., & Sellwood, J

    Debattista, V. P., & Sellwood, J. A. 2000, ApJ, 543, 704, doi: 10.1086/317148

  15. [15]

    2023, MNRAS, 518, 2712, doi: 10.1093/mnras/stac3184

    Dehnen, W., Semczuk, M., & Schönrich, R. 2023, MNRAS, 518, 2712, doi: 10.1093/mnras/stac3184

  16. [16]

    Revisiting the Excess of Bar-like Structures in TNG50 Early-type Galaxies: Consistency and Tension with Observations

    Du, H., Wang, Y., & Ge, J. 2026, arXiv e-prints, arXiv:2603.21279, doi: 10.48550/arXiv.2603.21279

  17. [17]

    1994, A&A, 285, 801

    Engstroem, S. 1994, A&A, 285, 801

  18. [18]

    B., Frogel, J

    Eskridge, P. B., Frogel, J. A., Pogge, R. W., et al. 2000, AJ, 119, 536, doi: 10.1086/301203

  19. [19]

    2022, ApJ, 940, 61, doi: 10.3847/1538-4357/ac9972

    Frankel, N., Pillepich, A., Rix, H.-W., et al. 2022, ApJ, 940, 61, doi: 10.3847/1538-4357/ac9972

  20. [20]

    2020, MNRAS, 491, 3655, doi: 10.1093/mnras/stz3101

    Garma-Oehmichen, L., Cano-Díaz, M., Hernández-Toledo, H., et al. 2020, MNRAS, 491, 3655, doi: 10.1093/mnras/stz3101

  21. [21]

    2022, MNRAS, 517, 5660, doi: 10.1093/mnras/stac3069 Géron, T., Smethurst, R

    Garma-Oehmichen, L., Hernández-Toledo, H., Aquino-Ortíz, E., et al. 2022, MNRAS, 517, 5660, doi: 10.1093/mnras/stac3069 Géron, T., Smethurst, R. J., Lintott, C., et al. 2023, MNRAS, 521, 1775, doi: 10.1093/mnras/stad501

  22. [22]

    2019, MNRAS, 482, 1733, doi: 10.1093/mnras/sty2715

    Guo, R., Mao, S., Athanassoula, E., et al. 2019, MNRAS, 482, 1733, doi: 10.1093/mnras/sty2715

  23. [23]

    2024, A&A, 691, A122, doi: 10.1051/0004-6361/202451028

    Habibi, A., Roshan, M., Hosseinirad, M., et al. 2024, A&A, 691, A122, doi: 10.1051/0004-6361/202451028

  24. [24]

    Knapen, J. H. 1999, in Astronomical Society of the Pacific Conference Series, Vol. 187, The Evolution of Galaxies on Cosmological Timescales, ed. J. E. Beckman & T. J. Mahoney, 72–87, doi: 10.48550/arXiv.astro-ph/9907290

  25. [25]

    C., & Shu, F

    Lin, C. C., & Shu, F. H. 1964, ApJ, 140, 646, doi: 10.1086/147955

  26. [26]

    E., Rand, R

    Meidt, S. E., Rand, R. J., & Merrifield, M. R. 2009, ApJ, 702, 277, doi: 10.1088/0004-637X/702/1/277

  27. [27]

    E., Rand, R

    Meidt, S. E., Rand, R. J., Merrifield, M. R., Debattista, V. P., & Shen, J. 2008, ApJ, 676, 899, doi: 10.1086/527530

  28. [28]

    R., & Kuijken, K

    Merrifield, M. R., & Kuijken, K. 1995, MNRAS, 274, 933, doi: 10.1093/mnras/274.3.933

  29. [29]

    2019, MNRAS, 490, 3234, doi: 10.1093/mnras/stz2306

    Nelson, D., Pillepich, A., Springel, V., et al. 2019, MNRAS, 490, 3234, doi: 10.1093/mnras/stz2306

  30. [30]

    2023, A&A, 673, A36, doi: 10.1051/0004-6361/202245463

    Pfenniger, D., Saha, K., & Wu, Y.-T. 2023, A&A, 673, A36, doi: 10.1051/0004-6361/202245463

  31. [31]

    2019, MNRAS, 490, 3196, doi: 10.1093/mnras/stz2338

    Pillepich, A., Nelson, D., Springel, V., et al. 2019, MNRAS, 490, 3196, doi: 10.1093/mnras/stz2338

  32. [32]

    2024, MNRAS, 535, 1721, doi: 10.1093/mnras/stae2165

    Pillepich, A., Sotillo-Ramos, D., Ramesh, R., et al. 2024, MNRAS, 535, 1721, doi: 10.1093/mnras/stae2165

  33. [33]

    R., Loebman, S

    Quinn, J. R., Loebman, S. R., Daniel, K. J., et al. 2026, ApJ, 997, 363, doi: 10.3847/1538-4357/ae2be1

  34. [34]

    2008, , 385, 1053, 10.1111/j.1365-2966.2008.12909.x

    Rautiainen, P., Salo, H., & Laurikainen, E. 2008, MNRAS, 388, 1803, doi: 10.1111/j.1365-2966.2008.13522.x 30

  35. [35]

    F., Lotz, J

    Rodriguez-Gomez, V., Snyder, G. F., Lotz, J. M., et al. 2019, MNRAS, 483, 4140, doi: 10.1093/mnras/sty3345

  36. [36]

    2022, MNRAS, 512, 5339, doi: 10.1093/mnras/stac816

    Rosas-Guevara, Y., Bonoli, S., Dotti, M., et al. 2022, MNRAS, 512, 5339, doi: 10.1093/mnras/stac816

  37. [37]

    L., Smith, L., & Evans, N

    Sanders, J. L., Smith, L., & Evans, N. W. 2019, MNRAS, 488, 4552, doi: 10.1093/mnras/stz1827

  38. [38]

    Sellwood, J. A. 2011, MNRAS, 410, 1637, doi: 10.1111/j.1365-2966.2010.17545.x

  39. [39]

    Sellwood, J. A. 2014, Reviews of Modern Physics, 86, 1, doi: 10.1103/RevModPhys.86.1

  40. [40]

    A., & Carlberg, R

    Sellwood, J. A., & Carlberg, R. G. 1984, ApJ, 282, 61, doi: 10.1086/162176

  41. [41]

    A., & Debattista, V

    Sellwood, J. A., & Debattista, V. P. 2006, ApJ, 639, 868, doi: 10.1086/499482

  42. [42]

    A., & Sparke, L

    Sellwood, J. A., & Sparke, L. S. 1988, MNRAS, 231, 25P, doi: 10.1093/mnras/231.1.25P

  43. [43]

    A., & Wilkinson, A

    Sellwood, J. A., & Wilkinson, A. 1993, Reports on Progress in Physics, 56, 173, doi: 10.1088/0034-4885/56/2/001

  44. [44]

    2024, A&A, 692, A159, doi: 10.1051/0004-6361/202451521

    Semczuk, M., Dehnen, W., Schönrich, R., & Athanassoula, E. 2024, A&A, 692, A159, doi: 10.1051/0004-6361/202451521

  45. [45]

    2020, Research in Astronomy and Astrophysics, 20, 159, doi: 10.1088/1674-4527/20/10/159

    Shen, J., & Zheng, X.-W. 2020, Research in Astronomy and Astrophysics, 20, 159, doi: 10.1088/1674-4527/20/10/159

  46. [46]

    C., & Rooke, P

    Speights, J. C., & Rooke, P. C. 2016, ApJ, 826, 2, doi: 10.3847/0004-637X/826/1/2

  47. [47]

    1981, in Structure and Evolution of Normal Galaxies, ed

    Toomre, A. 1981, in Structure and Evolution of Normal Galaxies, ed. S. M. Fall & D. Lynden-Bell, 111–136

  48. [48]

    Tremaine, S., & Weinberg, M. D. 1984, ApJL, 282, L5, doi: 10.1086/184292

  49. [49]

    G., Schinnerer, E., Emsellem, E., et al

    Williams, T. G., Schinnerer, E., Emsellem, E., et al. 2021, AJ, 161, 185, doi: 10.3847/1538-3881/abe243