Pith. sign in

REVIEW 3 major objections 5 minor 70 references

Stellar distributions around supermassive black holes in gas-rich nuclear star clusters

T0 review · 3 major / 5 minor · reviewed 2026-08-07 · deepseek-v4-flash

Pith's one-line read This paper derives a new steady-state stellar cusp, $f(E)\propto E^{\gamma+2}$, for stars around supermassive black holes embedded in gas-rich nuclear clusters, replacing the classical $p=-7/4$ cusp whenever gas drag dominates stellar…

desk verdict A clean limiting-case extension of Bahcall-Wolf to gas drag gives a new cusp slope α=γ+2, but one highlighted gas profile (Bondi, γ=-3/2) lands exactly on a singular point in the stellar scattering flux that the paper never addresses. read the letter →

arxiv 2506.04229 v2 pith:OTURXRW6 submitted 2025-06-04 astro-ph.GA astro-ph.HE

classification astro-ph.GAastro-ph.HE
keywords nuclearstarclusterssupermassiveblackholesstellarcuspgasdynamicalfrictionFokker-Planckequationtidaldisruptioneventsrelaxationgalacticnuclei
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

Gas in nuclear star clusters is normally ignored when predicting the stellar distribution around supermassive black holes. This paper argues that once gas is present, its drag on stars adds an energy flux that reshapes the steady-state cusp: in the gas-dominated limit the phase-space distribution becomes $f(E)\propto E^{\gamma+2}$, equivalent to a density $n(r)\propto r^{-(\gamma+7/2)}$ in a Keplerian potential, where $\gamma$ is the power-law index of the gas density. That replaces the classical $p=-7/4$ cusp whenever gas drag beats stellar scattering, and even subdominant gas leaves a residual inward flux that prevents the gas-free steady state from being exact. If true, rates of tidal disruption events, stellar collisions, and other nuclear transients must be corrected for the gas content of the cluster.

What carries the argument

The central object is the energy flux $F_E$ through energy space, the quantity that is made constant to find the steady state in the classical derivation. The paper adds a gas contribution $F_{\rm gas}=ER_g(E)$, where $R_g$ is the gas-induced particle flux computed from the supersonic gas-dynamical-friction dissipation rate $dE/dt=4\pi G^2 m\rho_g\ln\Lambda_g/v$. Equating the gas flux to a constant in the gas-dominated limit yields $\alpha=\gamma+2$; the convergence condition $\alpha-\gamma<3$ delimits the allowed parameter space.

What would settle it

Numerically integrate the full Fokker-Planck equation with the supersonic gas-drag term and a fixed power-law gas profile: if the relaxed distribution does not approach $\alpha=\gamma+2$ whenever the gas flux dominates, the central claim fails. Alternatively, resolved stellar cusps in gas-rich nuclear clusters whose observed slope does not track the independently measured gas-density slope would contradict the prediction.

Watch

Extended reading notes

Core claim

The paper extends the classical flux-balance derivation by adding a gas-drag energy flux. Starting from a power-law ansatz for the distribution function and gas density, it computes $F_{\rm gas}\propto E^{\alpha-\gamma-2}/(3+\gamma-\alpha)$ for supersonic gas dynamical friction, and shows that setting this flux constant gives $\alpha=\gamma+2$, which translates to $n(r)\propto r^{-(\gamma+7/2)}$ in a Keplerian potential. The paper identifies two limiting regimes, scattering-dominated and gas-dominated, with the transition near $M_{\rm gas}/M_\star\simeq10\%$, and notes that no single steady state exists in general: the gas-free cusp is always perturbed by a residual inward flux.

Load-bearing premise

The prediction rests on the gas density being a single power law $\rho_g\propto r^\gamma$ with a fixed index and on the supersonic gas-dynamical-friction law $dE/dt\propto\rho_g/v$ holding with a constant Coulomb logarithm; if the gas profile steepens with radius or the drag law differs, the exponent changes even if the qualitative effect survives.

Editorial extensions

If this is right

  • For a gas profile with $\gamma=-2$ (isothermal-type wind), the gas-dominated cusp is $n\propto r^{-3/2}$, shallower than the gas-free $r^{-7/4}$; for $\gamma=-3/2$ (Bondi-like), it is $n\propto r^{-2}$, steeper.
  • Gas-induced flux becomes comparable to stellar-scattering flux at $M_{\rm gas}/M_\star\gtrsim10\%$, so clusters with tens-of-percent gas fractions are in or near the modified regime.
  • Relaxation and mass-segregation timescales are shortened by a factor $\sim(1+\rho_g/\rho_\star)^{-1}$, meaning segregation proceeds a few times faster in gas-rich clusters.
  • TDE rates and related loss-cone transients change by a factor of a few because the relaxation time entering $\Gamma_{\rm TDE}$ is reduced.
  • Gas-driven inspiral can heat and expel the cluster gas on an estimated upper-limit timescale of $\sim800$ Myr, so the modified cusp may be an episodic rather than permanent state.

Reading between the lines

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

  • Editorial inference: if the gas density profile steepens with radius, the $\alpha=\gamma+2$ law predicts a broken power-law cusp whose break radius tracks the gas-profile break, a testable extension of the paper's single-power-law assumption.
  • Editorial inference: applied to a multi-mass cluster, the same flux-balance argument suggests that heavy remnants such as stellar-mass black holes sink faster and may form a steeper sub-cusp than the single-mass $\alpha=\gamma+2$, possibly accelerating extreme-mass-ratio inspiral rates in gas-rich nuclei.
  • Editorial inference: because the paper works only in energy space, gas-modified loss-cone refilling is not fully captured; an angular-momentum-dependent treatment could make TDE predictions diverge more strongly from the gas-free case than the factor-of-few quoted here.
Share X Bluesky LinkedIn Reddit HN

Editorial analysis

A structured set of objections, weighed in public.

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

Referee Report

3 major / 5 minor

Summary. This paper extends the Bahcall-Wolf (1976) steady-state stellar cusp derivation to include an energy dissipation term from gas dynamical friction. The authors model gas drag in a parameterized form, derive the gas-induced energy flux, and identify two limiting regimes: a scattering-dominated regime reproducing the standard Bahcall-Wolf slope α=1/4, and a gas-dominated regime where they predict f(E) ∝ E^{γ+2}, corresponding to a stellar density cusp n(r) ∝ r^{-(γ+7/2)}. They then explore the flux ratio as a function of gas fraction and gas profile slope, and discuss implications for tidal disruption event rates and relaxation in gas-rich nuclear star clusters.

Significance. The paper is clearly written and the limiting-case algebra is straightforward and self-contained against the Bahcall-Wolf benchmark. The qualitative idea that gas drag can alter the stellar cusp around a supermassive black hole is interesting and timely, and the discussion of observational implications is useful. However, the central prediction α=γ+2 has a self-consistency problem: for the fiducial gas density profiles (γ=-2 and γ=-3/2) the predicted α lies exactly on the poles of the stellar scattering flux, where the stellar flux diverges and cannot be neglected. This requires a revision of the central claim or a restriction to non-singular profiles.

major comments (3)
  1. [§4.2, Eqs. (9)-(10), (14)] The gas-dominated slope α=γ+2 coincides with singularities of the stellar scattering flux for the fiducial gas profiles: for γ=-2 (isothermal, used in Figs. 1-3) α=0, and for γ=-3/2 (Bondi) α=1/2. At these values the denominators of F_adv and F_cond in Eqs. (9)-(10) vanish, so F_star diverges rather than being negligible. Hence the assumption |F_gas/F_star| >> 1 that underlies setting F_gas alone constant in Eq. (14) is violated, and the predicted steady state is not self-consistent. This directly affects the quantitative claim n(r) ∝ r^{-3/2} for the isothermal profile. The paper should either restrict the gas-dominated prediction to γ values for which α=γ+2 is not one of the singular points, or demonstrate that the full Fokker-Planck equation regularizes these poles and yields the same slope.
  2. [§4.2, §5.5] The statement that all intermediate cases will obey an interpolation between the two limiting cases is asserted without derivation. The steady-state condition is F_star + F_gas = constant; since F_star ∝ E^{2α-1/2} and F_gas ∝ E^{α-γ-2} have different energy dependences, a constant total flux does not generally reduce to an interpolation between α=1/4 and α=γ+2. A proper treatment, or at least an explicit statement that this is a heuristic expectation pending full Fokker-Planck solutions, is needed.
  3. [§4.3, Figs. 1-3] The flux-ratio maps and the 10% threshold are computed at fixed α=1/4. If gas significantly alters the distribution, α changes and the ratio |F_gas/F_star| should be evaluated self-consistently at the new α. As it stands, the threshold is only indicative; the paper should clarify this or provide a self-consistent estimate.
minor comments (5)
  1. [Introduction] Several citation placeholders with '?;' appear in the second paragraph (e.g., after 'evolution of binaries' and after 'Li & Lai 2024'); these should be filled with proper references.
  2. [§3.1] The sentence 'the dependence of the NSCs masses is shallower, and scales as ∝ σ^2' is grammatically incomplete; please rephrase.
  3. [Figure 3 caption] The caption contains a duplicated word: 'correspondingly. correspondingly.' should be corrected to a single occurrence.
  4. [§1] The phrase 'as well as the altering the formation rates and properties' in the Introduction is garbled; it should likely read 'as well as altering the formation rates and properties'.
  5. [§3, Eq. (2) and Eq. (8)] The symbol F_gas is used both for the drag force (Eq. 2) and for the energy flux (Eq. 8); consider using distinct notation to avoid ambiguity.

Circularity Check

0 steps flagged · score 0.0 of 10

No circularity: the gas-dominated cusp α=γ+2 is derived by setting a derived gas flux constant, not by fitting and not by self-citation.

full rationale

The paper's derivation chain is self-contained. The gas-dominated prediction α=γ+2 is obtained by requiring the gas-induced energy flux (Eq. 14) to be energy-independent, exactly the same steady-flux logic used to recover the Bahcall-Wolf slope from the scattering flux (Eq. 1). The gas density index γ, the supersonic GDF normalization, and ln Λg=3.1 are explicit inputs taken from the cited drag/atmosphere models (Ostriker et al. 1999; Tagawa et al. 2020; Quataert 2004; De Colle et al. 2012), and none is adjusted to reproduce the target slope; the paper even calls the gas profile uncertain in §3.1. No fitted parameter is renamed as a prediction. The numerous co-authored citations supply context and gas-model precedents, but the central exponent follows from the manuscript's own Eqs. (8), (13), and (14), so self-citation is not load-bearing. The skeptical observation that the predicted α=0 (γ=−2) and α=1/2 (γ=−3/2) lie on poles of the stellar flux (Eqs. 9–10) raises an internal-consistency question for the limiting-case expansion, not a circular-input question; the paper's caveat that 'A detailed analysis of the problem described here requires solving full Fokker-Planck equations' (Section 5.5) is the acknowledged place where that consistency would need to be checked. Since no step assumes the conclusion it claims to derive, there is no circularity to report.

Assumptions & free parameters 4 free parameters · 5 assumptions · 0 invented entities

The paper's central prediction is parameterized by the gas density power-law index gamma and the gas fraction xi, both of which are inputs rather than fitted outputs. The biggest assumptions are the additive energy-flux treatment and the supersonic GDF drag law. No new physical entities are introduced.

free parameters (4)
  • gas density power-law index gamma = -2 (fiducial), -3/2 (Bondi)
    The gas density profile rho_g proportional to r^gamma is uncertain; the derived cusp slope alpha = gamma + 2 depends linearly on gamma. The paper adopts gamma = -2 (isothermal) or gamma = -3/2 (Bondi) in Section 3.1.
  • gas-to-stars mass ratio xi = M_gas / M_star = 0.1 (fiducial, varied in figures)
    Controls the relative strength of gas drag; the 10 percent threshold is read off the figures under fiducial assumptions, and the metric is energy-dependent.
  • Coulomb logarithm for gas ln Lambda_g = 3.1
    Sets the normalization of the gas drag force; taken from Tagawa et al. 2020.
  • drag force velocity exponent beta = -2 (supersonic GDF)
    Parameterizes the drag law in equation 4; the paper also considers the subsonic limit. The central result scales with beta.
assumptions (5)
  • domain assumption Stellar distribution is spherically symmetric, isotropic in velocity, and single-mass; interactions are weak and slow (Fokker-Planck regime).
    Inherited from Bahcall & Wolf 1976; stated in Section 4.1 and caveated in Section 5.5.
  • domain assumption The total energy flux is the sum of the stellar scattering flux and the gas drag flux (F_E = F_star + F_gas).
    Equation 7; assumes gas drag acts as an independent additive energy dissipation channel.
  • domain assumption The gas is stationary and follows a power-law density profile rho_g(r) = rho_g0 (r / R_inf)^gamma.
    Section 3.1; the paper notes the gas profile is uncertain.
  • domain assumption Gas drag is modeled by the supersonic GDF formula with dE/dt = 4 pi G^2 m rho_g ln Lambda_g / v (equation 13).
    From Ostriker et al. 1999; caveated in Section 5.5; other drag models may change the slope.
  • ad hoc to paper A steady state corresponds to constant energy flux in the gas-dominated limit (F_gas = const).
    Section 4.2; this is the defining condition for the new cusp slope, but it ignores the net inward flux that prevents a true equilibrium.

how reviews work

0 comments
Cite this review

Pith. "Pith review of Stellar distributions around supermassive black holes in gas-rich nuclear star clusters." pith.science (2026). https://pith.science/paper/OTURXRW6

@misc{pith2026250604229,
  author       = {Pith},
  title        = {Pith review of: Stellar distributions around supermassive black holes in gas-rich nuclear star clusters},
  year         = {2026},
  howpublished = {\url{https://pith.science/paper/OTURXRW6}},
  note         = {Machine review of arXiv:2506.04229}
}
read the original abstract

We study the stellar distribution around supermassive black holes (SMBHs) in gas-rich nuclear star clusters (NSCs). NSCs could contain vast amounts of gas, which contribute significantly to shaping the stellar distribution, typically altering the stellar density cusp from the usual Bahcall \& Wolf 1976 solution and consequently affecting the dynamics in the NSC. The dense gaseous environment in NSCs gives rise to dynamical phenomena that are otherwise rare in other gas-free environments. Here we extend the derivation introduced in Bahcall \& Wolf 1976 to include an additional energy dissipation term associated with gas drag. We examine the effect of different forms of gas drag on the stellar density distribution. Finally, we discuss implications on the rates of tidal disruption events and other transients triggered by stellar interactions in gas-rich galactic nuclei.

Figures

Figures reproduced from arXiv: 2506.04229 by the authors.

Figure 1
Figure 1. The ratio between gas-induced and scattering energy fluxes, at different locations at the cluster, or equiv￾alently, different specific energies, for different mass ratios between gas and stars. The energies are normalized by the specific energy at the radius of influence E0 = GM•/Rinf. The power laws of the phase space distribution and gas den￾sity are taken to be α = 1/4, γ = −2 correspondingly. In the left panel … view at source ↗
Figure 2
Figure 2. Left: Colormap of the ratio of fluxes (color) as calculated for different gas-to-stars mass ratios and gas density power law γ. The solid line is the contour where |Fgas/F⋆| = 1. The energies are evaluated at 0.1 pc and the power law for the phase space distribution is taken to be α = 1/4. The dashed line is the profile at the limit of gas-domination, for the given α. Right: Colormap of the ratio of fluxes (color) a… view at source ↗
Figure 3
Figure 3. Left: Colormap of the ratio of fluxes (color) as calculated for different gas-to-stars ratios and phase space density power laws α. The solid line is the contour where |Fgas/F⋆| = 1. The energies are evaluated at 0.1 pc and the power law for gas density profile taken to be γ = −2. Right: Colormap of the ratio of fluxes (color) as calculated for different gas-to-stars ratios and energies relative to the energy at the… view at source ↗

Discussion (0). Sign in to comment.

Reference graph

Works this paper leans on

70 extracted references · 11 canonical work pages

  1. [1]

    2009, ApJ, 697, 1861, doi: 10.1088/0004-637X/697/2/1861

    Alexander, T., & Hopman, C. 2009, ApJ, 697, 1861, doi: 10.1088/0004-637X/697/2/1861

  2. [2]

    2018, Living Reviews in Relativity, 21, 4, doi: 10.1007/s41114-018-0013-8

    Amaro-Seoane, P. 2018, Living Reviews in Relativity, 21, 4, doi: 10.1007/s41114-018-0013-8

  3. [3]

    R., Freitag, M., et al

    Amaro-Seoane, P., Gair, J. R., Freitag, M., et al. 2007, Classical and Quantum Gravity, 24, R113, doi: 10.1088/0264-9381/24/17/R01

  4. [4]

    2019, ApJ, 884, 22, doi: 10.3847/1538-4357/ab3466

    Antoni, A., MacLeod, M., & Ramirez-Ruiz, E. 2019, ApJ, 884, 22, doi: 10.3847/1538-4357/ab3466

  5. [5]

    2015, ApJ, 812, 72, doi: 10.1088/0004-637X/812/1/72

    Antonini, F., Barausse, E., & Silk, J. 2015, ApJ, 812, 72, doi: 10.1088/0004-637X/812/1/72

  6. [6]

    J., Lubow, S

    Artymowicz, P., Clarke, C. J., Lubow, S. H., & Pringle, J. E. 1991, ApJL, 370, L35, doi: 10.1086/185971

  7. [7]

    Artymowicz, P., Lin, D. N. C., & Wampler, E. J. 1993, ApJ, 409, 592, doi: 10.1086/172690

  8. [8]

    N., & Ostriker, J

    Bahcall, J. N., & Ostriker, J. P. 1975, Nature, 256, 23, doi: 10.1038/256023a0

Show all 70 references
  1. [9]

    N., & Wolf, R

    Bahcall, J. N., & Wolf, R. A. 1976, ApJ, 209, 214, doi: 10.1086/154711 —. 1977, ApJ, 216, 883, doi: 10.1086/155534

  2. [10]

    2007, PASA, 24, 77, doi: 10.1071/AS07008

    Bekki, K. 2007, PASA, 24, 77, doi: 10.1071/AS07008

  3. [11]

    2008, Galactic Dynamics: Second Edition

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

  4. [12]

    2014, A&A, 562, A21, doi: 10.1051/0004-6361/201322464

    Cicone, C., Maiolino, R., Sturm, E., et al. 2014, A&A, 562, A21, doi: 10.1051/0004-6361/201322464

  5. [13]

    Cohn, H., & Kulsrud, R. M. 1978, ApJ, 226, 1087, doi: 10.1086/156685

  6. [14]

    J., Fuerst, S

    Dai, L. J., Fuerst, S. V., & Blandford, R. 2010, MNRAS, 402, 1614, doi: 10.1111/j.1365-2966.2009.16038.x De Colle, F., Guillochon, J., Naiman, J., & Ramirez-Ruiz, E. 2012, ApJ, 760, 103, doi: 10.1088/0004-637X/760/2/103

  7. [15]

    2015, ApJ, 809, 143, doi: 10.1088/0004-637X/809/2/143

    Do, T., Kerzendorf, W., Winsor, N., et al. 2015, ApJ, 809, 143, doi: 10.1088/0004-637X/809/2/143

  8. [16]

    2024, ApJ, 972, 193, doi: 10.3847/1538-4357/ad5cf2

    Dodici, M., & Tremaine, S. 2024, ApJ, 972, 193, doi: 10.3847/1538-4357/ad5cf2

  9. [17]

    2021, ARA&A, 59, 21, doi: 10.1146/annurev-astro-111720-030029

    Gezari, S. 2021, ARA&A, 59, 21, doi: 10.1146/annurev-astro-111720-030029

  10. [18]

    2016, MNRAS, 461, 3620, doi: 10.1093/mnras/stw1570

    Guillard, N., Emsellem, E., & Renaud, F. 2016, MNRAS, 461, 3620, doi: 10.1093/mnras/stw1570

  11. [19]

    2013, ApJ, 767, 25, doi: 10.1088/0004-637X/767/1/25

    Guillochon, J., & Ramirez-Ruiz, E. 2013, ApJ, 767, 25, doi: 10.1088/0004-637X/767/1/25

  12. [20]

    B., Igumenshchev, I

    Ivanov, P. B., Igumenshchev, I. V., & Novikov, I. D. 1998, ApJ, 507, 131, doi: 10.1086/306324

  13. [21]

    2019, ApJ, 876, 142, doi: 10.3847/1538-4357/ab158b

    Kaaz, N., Antoni, A., & Ramirez-Ruiz, E. 2019, ApJ, 876, 142, doi: 10.3847/1538-4357/ab158b

  14. [22]

    2023, ApJ, 944, 44, doi: 10.3847/1538-4357/aca967

    Ramirez-Ruiz, E. 2023, ApJ, 944, 44, doi: 10.3847/1538-4357/aca967

  15. [23]

    2007, A&A, 470, 11, doi: 10.1051/0004-6361:20066068

    Karas, V., & Šubr, L. 2007, A&A, 470, 11, doi: 10.1051/0004-6361:20066068

  16. [24]

    Kaur, K., & Stone, N. C. 2025, ApJ, 979, 172, doi: 10.3847/1538-4357/ad9b86

  17. [25]

    2009, ApJL, 698, L64, doi: 10.1088/0004-637X/698/1/L64

    Keshet, U., Hopman, C., & Alexander, T. 2009, ApJL, 698, L64, doi: 10.1088/0004-637X/698/1/L64

  18. [26]

    2006, Mem

    Komossa, S. 2006, Mem. Soc. Astron. Italiana, 77, 733

  19. [27]

    Kormendy, J., & Ho, L. C. 2013, ARA&A, 51, 511, doi: 10.1146/annurev-astro-082708-101811

  20. [28]

    Krause, M. G. H., Charbonnel, C., Bastian, N., & Diehl, R. 2016, A&A, 587, A53, doi: 10.1051/0004-6361/201526685

  21. [29]

    2024, MNRAS, 531, 133, doi: 10.1093/mnras/stae1145

    Kritos, K., Berti, E., & Silk, J. 2024, MNRAS, 531, 133, doi: 10.1093/mnras/stae1145

  22. [30]

    H., Ramirez-Ruiz, E., & van de Ven, G

    Lee, W. H., Ramirez-Ruiz, E., & van de Ven, G. 2010, ApJ, 720, 953, doi: 10.1088/0004-637X/720/1/953

  23. [31]

    J., & Valtonen, M

    Lehto, H. J., & Valtonen, M. J. 1996, ApJ, 460, 207, doi: 10.1086/176962

  24. [32]

    M., Li, H., Lai, D., & Li, S

    Li, J., Dempsey, A. M., Li, H., Lai, D., & Li, S. 2023, ApJL, 944, L42, doi: 10.3847/2041-8213/acb934

  25. [33]

    2024, MNRAS, 529, 348, doi: 10.1093/mnras/stae504

    Li, R., & Lai, D. 2024, MNRAS, 529, 348, doi: 10.1093/mnras/stae504

  26. [34]

    P., & Shapiro, S

    Lightman, A. P., & Shapiro, S. L. 1977, ApJ, 211, 244, doi: 10.1086/154925

  27. [35]

    Lin, D. N. C., & Murray, S. D. 2007, ApJ, 661, 779, doi: 10.1086/515387

  28. [36]

    Linial, I., & Metzger, B. D. 2023, ApJ, 957, 34, doi: 10.3847/1538-4357/acf65b

  29. [37]

    H., Kruegel, E., & Tutukov, A

    Loose, H. H., Kruegel, E., & Tutukov, A. 1982, A&A, 105, 342

  30. [38]

    2014, ApJ, 794, 9, doi: 10.1088/0004-637X/794/1/9

    MacLeod, M., Goldstein, J., Ramirez-Ruiz, E., Guillochon, J., & Samsing, J. 2014, ApJ, 794, 9, doi: 10.1088/0004-637X/794/1/9

  31. [39]

    2013, ApJ, 777, 133, doi: 10.1088/0004-637X/777/2/133

    MacLeod, M., Ramirez-Ruiz, E., Grady, S., & Guillochon, J. 2013, ApJ, 777, 133, doi: 10.1088/0004-637X/777/2/133

  32. [40]

    McKernan, B., Ford, K. E. S., Lyra, W., & Perets, H. B. 2012, MNRAS, 425, 460, doi: 10.1111/j.1365-2966.2012.21486.x 9

  33. [41]

    C., & Hernquist, L

    Mihos, J. C., & Hernquist, L. 1996, ApJ, 464, 641, doi: 10.1086/177353 Milosavljević, M. 2004, ApJL, 605, L13, doi: 10.1086/420696

  34. [42]

    P., Ramirez-Ruiz, E., & Lin, D

    Naiman, J. P., Ramirez-Ruiz, E., & Lin, D. N. C. 2009, ApJL, 705, L153, doi: 10.1088/0004-637X/705/2/L153

  35. [43]

    P., Ramirez-Ruiz, E., & Lin, D

    Naiman, J. P., Ramirez-Ruiz, E., & Lin, D. N. C. 2011, ApJ, 735, 25, doi: 10.1088/0004-637X/735/1/25 O’Leary, R. M., Rasio, F. A., Fregeau, J. M., Ivanova, N., & O’Shaughnessy, R. 2006, ApJ, 637, 937, doi: 10.1086/498446

  36. [44]

    C., Gammie, C

    Ostriker, E. C., Gammie, C. F., & Stone, J. M. 1999, ApJ, 513, 259, doi: 10.1086/306842

  37. [45]

    Ostriker, J. P. 1983, ApJ, 273, 99, doi: 10.1086/161351

  38. [46]

    Peebles, P. J. E. 1972, ApJ, 178, 371, doi: 10.1086/151797

  39. [47]

    2004, ApJ, 613, 322, doi: 10.1086/422973

    Quataert, E. 2004, ApJ, 613, 322, doi: 10.1086/422973

  40. [48]

    2015, ApJL, 802, L22, doi: 10.1088/2041-8205/802/2/L22

    Ramirez-Ruiz, E., Trenti, M., MacLeod, M., et al. 2015, ApJL, 802, L22, doi: 10.1088/2041-8205/802/2/L22

  41. [49]

    Rees, M. J. 1988, Nature, 333, 523, doi: 10.1038/333523a0

  42. [50]

    L., Chatterjee, S., & Rasio, F

    Rodriguez, C. L., Chatterjee, S., & Rasio, F. A. 2016, PhRvD, 93, 084029, doi: 10.1103/PhysRevD.93.084029

  43. [51]

    2023, ApJ, 951, 14, doi: 10.3847/1538-4357/acd54f

    Rom, B., Linial, I., & Sari, R. 2023, ApJ, 951, 14, doi: 10.3847/1538-4357/acd54f

  44. [52]

    C., & MacLeod, M

    Rose, S. C., & MacLeod, M. 2024, ApJL, 963, L17, doi: 10.3847/2041-8213/ad251f

  45. [53]

    P., Böker, T., et al

    Rossa, J., van der Marel, R. P., Böker, T., et al. 2006, AJ, 132, 1074, doi: 10.1086/505968

  46. [54]

    2009, ApJL, 705, L128, doi: 10.1088/0004-637X/705/2/L128

    Rosswog, S., Kasen, D., Guillochon, J., & Ramirez-Ruiz, E. 2009, ApJL, 705, L128, doi: 10.1088/0004-637X/705/2/L128

  47. [55]

    2023, MNRAS, 524, 2770, doi: 10.1093/mnras/stad1926

    Rowan, C., Boekholt, T., Kocsis, B., & Haiman, Z. 2023, MNRAS, 524, 2770, doi: 10.1093/mnras/stad1926

  48. [56]

    2025, MNRAS, doi: 10.1093/mnras/staf547

    Rowan, C., Whitehead, H., Fabj, G., et al. 2025, MNRAS, doi: 10.1093/mnras/staf547

  49. [57]

    Rozner, M., Generozov, A., & Perets, H. B. 2023, MNRAS, 521, 866, doi: 10.1093/mnras/stad603

  50. [58]

    Rozner, M., & Perets, H. B. 2022, ApJ, 931, 149, doi: 10.3847/1538-4357/ac6d55 —. 2024, ApJ, 968, 80, doi: 10.3847/1538-4357/ad4bdd

  51. [59]

    A., Samsing, J., & Perets, H

    Rozner, M., Trani, A. A., Samsing, J., & Perets, H. B. 2025, MNRAS, 537, 1220, doi: 10.1093/mnras/staf072

  52. [60]

    2014, ApJ, 784, 71, doi: 10.1088/0004-637X/784/1/71

    Samsing, J., MacLeod, M., & Ramirez-Ruiz, E. 2014, ApJ, 784, 71, doi: 10.1088/0004-637X/784/1/71

  53. [61]

    Scott, N., & Graham, A. W. 2013, ApJ, 763, 76, doi: 10.1088/0004-637X/763/2/76

  54. [62]

    L., & Lightman, A

    Shapiro, S. L., & Lightman, A. P. 1976, Nature, 262, 743, doi: 10.1038/262743a0

  55. [63]

    1987, Dynamical evolution of globular clusters

    Spitzer, L. 1987, Dynamical evolution of globular clusters

  56. [64]

    C., Metzger, B

    Stone, N. C., Metzger, B. D., & Haiman, Z. 2017, MNRAS, 464, 946, doi: 10.1093/mnras/stw2260

  57. [65]

    2020, ApJ, 898, 25, doi: 10.3847/1538-4357/ab9b8c

    Tagawa, H., Haiman, Z., & Kocsis, B. 2020, ApJ, 898, 25, doi: 10.3847/1538-4357/ab9b8c

  58. [66]

    2019, Monthly Notices of the Royal Astronomical Society, 487, 819, doi: 10.1093/mnras/stz1280

    Trebitsch, M., Volonteri, M., & Dubois, Y. 2019, Monthly Notices of the Royal Astronomical Society, 487, 819, doi: 10.1093/mnras/stz1280

  59. [67]

    P., Mapelli, M., Périgois, C., et al

    Vaccaro, M. P., Mapelli, M., Périgois, C., et al. 2024, A&A, 685, A51, doi: 10.1051/0004-6361/202348509

  60. [68]

    2017, ApJ, 848, 10, doi: 10.3847/1538-4357/aa8cc8

    Vasiliev, E. 2017, ApJ, 848, 10, doi: 10.3847/1538-4357/aa8cc8

  61. [69]

    2023, arXiv e-prints, arXiv:2309.11561, doi: 10.48550/arXiv.2309.11561

    Whitehead, H., Rowan, C., Boekholt, T., & Kocsis, B. 2023, arXiv e-prints, arXiv:2309.11561, doi: 10.48550/arXiv.2309.11561

  62. [70]

    Zentsova, A. S. 1983, Ap&SS, 95, 11, doi: 10.1007/BF00661152

Pith tools

Reviewed August 7, 2026 · model on record in the stance chip above.