Pith. sign in

REVIEW 3 major objections 5 minor 25 references

Galaxy infall models for arbitrary velocity directions

T0 review · 3 major / 5 minor · reviewed 2026-08-10 · deepseek-v4-flash

Challenge this review Re-run · record.json Download PDF Read on arXiv ↗ Review JSON

Pith's one-line read Infall-model velocities misestimate individual radial velocities for most galaxies, yet the dispersions they yield systematically bracket the true velocity dispersion, predicting the M81 group's at 99–180 km/s.

desk verdict Solid kinematic generalization and a useful dispersion-bracketing result, but the M81 application is internally inconsistent and the quoted numbers don't follow from the stated fits. read the letter →

arxiv 2501.13149 v3 pith:Z4ZUNG3W submitted 2025-01-22 astro-ph.GA astro-ph.COastro-ph.IMgr-qc

Jenny Wagner , David Benisty This is my paper · ORCID
classification astro-ph.GAastro-ph.COastro-ph.IMgr-qc
keywords radialinfallvelocityminormodelmajordispersionline-of-sightIllustrissimulationgalaxygroupsM81group
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 whether the two standard infall models — the minor and major models used to turn measured line-of-sight velocities into the radial velocity between a galaxy and a group — deliver what observers need. Working from the exact kinematics of a binary motion, the authors show that the two recipes are just different projections of one cosmology-independent velocity identity, and that both are accurate only under a fine-tuned ratio condition involving the unobservable velocity components perpendicular to the line of sight. Tested on more than 5000 subhalos around 344 halos in the Illustris-3 simulation, the individual model velocities fail: the true radial velocity lies between the two model estimates for only about 34% of subhalos, even at angular separations below $10^\circ$. The positive finding is that the scatter statistics survive — the velocity dispersions computed from the model velocities bracket the true dispersion for most halos, and for distant systems the plain difference of line-of-sight velocities reproduces the true dispersion almost exactly — which is why the authors can still predict the M81-group radial velocity dispersion and argue that dispersion-based mass estimates remain trustworthy.

What carries the argument

The load-bearing object is the exact relative-velocity decomposition of two galaxies into radial and tangential parts: projecting $\mathbf{v}_2 - \mathbf{v}_1$ onto the connection line $\hat{\mathbf{r}}_{21}$ gives Eq. (22), which contains the observable line-of-sight components, the angular separation $\theta$, the distances $r_1, r_2$, and the unobservable perpendicular speeds $|v_{\perp 1}|$ and $|v_{\perp 2}|$. Two derived conditions carry the argument. First, the fine-tuning condition $|v_{\perp 1}|/|v_{\perp 2}| = |r_1|/|r_2|$ is the only generic situation in which the perpendicular terms vanish, and it fixes whether the minor and major models over- or underestimate the true radial velocity. Second, the small-angle identity $|v_r| \approx |v_{l2}| - |v_{l1}|$ (Eq. 46) makes all models coincide for small $\theta$, and in the simulation it reproduces the true velocity dispersion almost exactly for distant halos, converting a kinematic approximation into a practical dispersion estimator.

What would settle it

Measure the full three-dimensional velocities of M81-group members, for instance proper motions of its dwarf galaxies from high-precision astrometry, compute the true radial velocity dispersion of the group, and check whether it falls inside the predicted 142–180 km/s bracket and near the $(99 \pm 36)$ km/s line-of-sight-difference estimate. A cheaper falsification is to rerun the dispersion calibration on a higher-resolution simulation, such as Illustris-1 or TNG, with the same M81-like selection: if the fitted slopes and intercepts move by more than their stated $1\sigma$ confidence bounds, the M81 prediction loses its calibration anchor.

Watch

Extended reading notes

Core claim

The paper's central claim is that the minor and major infall models are not rival physical pictures of galaxy motion but two projections of a single, cosmology-independent kinematics identity for the relative velocity $\mathbf{v}_2 - \mathbf{v}_1$ of two galaxies: the minor model projects the line-of-sight velocity components onto the connection line $\hat{\mathbf{r}}_{21}$, while the major model projects onto one galaxy's line of sight and divides by a distance factor. Because the exact radial-velocity expression contains the unobservable perpendicular components $|v_{\perp 1}|$ and $|v_{\perp 2}|$, each model is accurate only under the fine-tuned ratio condition $|v_{\perp 1}|/|v_{\perp 2}| = |r_1|/|r_2|$, which real subhalos essentially never satisfy: in Illustris-3, more than 90% of the 5036 subhalos have non-negligible perpendicular or tangential velocity, and only 34% have their true radial velocity bracketed by the two model estimates. The constructive part of the claim is that the velocity dispersions built from the model velocities are systematically related to the true dispersion — the minor model underestimates it, the major model overestimates it, and the small-angle difference of line-of-sight velocities, $|v_{l2}| - |v_{l1}|$, matches it almost one-to-one for halos beyond 18 Mpc — so that linear calibrations yield reliable brackets on the true dispersion. Applied to M81-group observations, the calibrated relations give a radial velocity dispersion of $(180 \pm 42)$ km/s from the minor model, $(142 \pm 64)$ km/s from the major model, and $(99 \pm 36)$ km/s from the line-of-sight difference, with the last identified as the most likely value because the M81 group satisfies the small-angle condition.

Load-bearing premise

The load-bearing premise is that the 281 Illustris-3 halos selected to mimic the M81 group — matched in mass, distance, subhalo count, and observer geometry — are representative enough of the real, actively merging M81 group that the simulated linear calibration between infall-model dispersion and true dispersion carries over to the observed M81 velocities.

Editorial extensions

If this is right

  • Minor- and major-model velocity dispersions bracket the true velocity dispersion for most simulated halos, so dispersion-based quantities such as virial masses can be bounded even where individual infall velocities are untrustworthy.
  • For structures far enough from the observer that $\theta < 10^\circ$, the velocity dispersion inferred from the difference of line-of-sight velocities alone coincides with the true dispersion, justifying this shortcut for high-redshift groups and clusters.
  • The M81-group's radial velocity dispersion is predicted at $(99 \pm 36)$ km/s from the line-of-sight difference, with the two infall models providing a conservative bracket of roughly 142–180 km/s.
  • Selecting galaxies at large distances or along the line of sight in front of and behind a cluster centre does not suppress the perpendicular and tangential velocity components, so individual infall-model velocities cannot be used for precise radial-velocity work.
  • The major infall model's motivation from a vanishing total angular momentum fails for individual halos; the model retains its value as a dispersion-bounding estimator rather than an exact velocity predictor.

Reading between the lines

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

  • A decisive external test is available: for any nearby group whose member velocities can be measured in three dimensions, whether by proper-motion surveys or high-resolution zoom simulations, one can check that the dispersion-bracket property holds outside Illustris-3 and that the M81 prediction of roughly 99–180 km/s contains the measured dispersion.
  • Because the fitted dispersion calibrations come from one simulation suite and one halo-selection recipe, their transfer to real groups is a testable hypothesis; rerunning the calibration with a higher-resolution simulation or a different halo finder would show whether the slopes and intercepts are stable or selection-dependent.
  • The paper's kinematics-only treatment suggests the bracket property is cosmology-independent; a natural check is whether the same dispersion brackets appear in simulations with modified gravity or different expansion histories, where the Hubble-flow term the models assume would differ.
  • If the line-of-sight-difference dispersion remains unbiased for all small-angle systems, virial masses of high-redshift clusters derived from single-spectroscopy surveys would rest on firmer footing; a comparison against X-ray or Sunyaev-Zeldovich mass estimates could test this directly.
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 generalizes the minor and major infall models of Karachentsev & Kashibadze (2006) to arbitrary velocity directions, deriving exact geometric expressions for the radial and tangential components of the relative velocity between two galaxies in terms of observable line-of-sight components, distances, and angular separation. The authors test the models on Illustris-3 simulated halos, finding that the infall-model velocities themselves reproduce the true radial velocity only for a minority (~34%) of subhalos, whereas the velocity dispersions computed from the infall-model velocities bracket the true dispersion for most halos. They then apply the models to the M81 group, quoting debiased radial-velocity dispersions of (180±42), (142±64), and (99±36) km/s from the minor, major, and line-of-sight-difference estimators.

Significance. The purely kinematical derivation in Sect. 2 is a valuable contribution: it shows that the two classical infall models correspond to different projections of the same relative-velocity vector and that they are cosmology-independent. The simulation analysis provides a concrete, quantitative warning that perpendicular and tangential velocity components cannot be neglected even at small angular separations, and the demonstration that the infall-model dispersions bracket the true dispersion is a practically useful result for group/cluster studies. The paper also makes a falsifiable prediction for the M81 group. However, the M81 prediction is currently presented with internally inconsistent bound labels and non-reproducible numbers, so a revision is needed before the headline claim can be accepted.

major comments (3)
  1. [Abstract and Sect. 5.2] The abstract labels the minor-infall estimate as an 'upper bound' and the major-infall estimate as a 'lower bound' on the M81 radial-velocity dispersion, but Sect. 4 and Fig. 7 establish the opposite bias: the minor infall model systematically underestimates the true dispersion and the major infall model systematically overestimates it. If the raw infall-model dispersions are to serve as bounds, the minor model provides the lower bound and the major model the upper bound. This reversal must be corrected in the abstract and in the conclusions.
  2. [Sect. 5.2, Eqs. (63)-(65)] The quoted debiased dispersions (180±42, 142±64, 99±36 km/s) are not derivable from the stated linear fits in Fig. 10 (centre). Using the natural inversion sigma_true = (sigma_obs - b)/m with the given fits (minor: m=0.53, b=22.21 km/s; major: m=4.01, b=254.60 km/s; Eq. (46): m=1.03, b=37.31 km/s) yields approximate values of 139, 77, and 63 km/s, not 180, 142, and 99. The quoted values are close to sigma_obs/m, which ignores the intercept b; if that is the intended bias correction, it should be stated explicitly with proper error propagation from both m and b. As written, the M81 prediction is not reproducible from the presented fits.
  3. [Sect. 5.2, Bayesian estimates] The Bayesian re-analysis in the same section gives different central values (150, 88, 100 km/s for minor, major, and Delta-v models) from the abstract's (180, 142, 99). The paper does not explain which set of numbers is the final prediction, nor does it reconcile the two. This ambiguity affects the headline claim and needs to be resolved.
minor comments (5)
  1. [Sect. 4, linear fit description] The description of the linear fit '|v_inf| = m |v_r| ... with its 1-sigma confidence bounds b_v' is ambiguous: are the b_v values (81.06 km/s etc.) intercepts or scatter bounds? If intercepts, include them in the equation; if bounds, report them differently. This ambiguity propagates to the calibration fits in Sect. 5.
  2. [Fig. 5 (left)] The text reports a major-infall fit (m_v=1.01, b_v=5578.32 km/s) but states the fit is not shown because its confidence bound covers the entire plot; this should be clarified, since the reported numbers are otherwise untestable.
  3. [Sect. 5.1] The M81-like halo selection does not explicitly select for merging groups with strong interactions like M81/M82/NGC 3077; the authors note that the simulated structures may not fully represent the M81 group, but a more quantitative discussion of this extrapolation (e.g., using the 100 kpc offset criterion as a proxy for the merging state) would strengthen the application.
  4. [Abstract] The phrase 'for more than 90% of all, more than 5000 infalling subhalos' is grammatically awkward and should be rephrased for clarity.
  5. [Sect. 2.1] The statement 'Amplitudes |.| can be negative' is confusing because the notation |.| is normally reserved for non-negative magnitudes; the paper already uses ||.||_2 for the latter, so consider using a different symbol for the signed amplitude.

Circularity Check

0 steps flagged · score 0.0 of 10

No circularity: the infall-model equations are vector-projection identities, the Illustris simulation is an independent test/calibration, and the self-citations are not load-bearing; the M81 numeric/label inconsistencies are reproducibility issues, not circularity.

full rationale

The paper's central derivation (Sect. 2, Eqs. 22-46) is a direct vector-projection identity: the true radial velocity is Eq. (22), the minor infall model is the same expression with the perpendicular terms dropped (Eq. 34), and the major infall model is the projection onto one line of sight (Eqs. 37-38). No quantity in these equations is defined in terms of the quantity it claims to predict, so there is no self-definitional reduction. The Illustris-3 application (Sects. 4-5) provides an external, independent benchmark: the fit parameters m_sigma and b_sigma are fitted to simulated halos and then applied to observed M81 dispersions; the M81 observations were not used to fit those parameters, so the calibration is not a fitted input disguised as a prediction. The self-citations (Benisty et al. 2022, 2025a, 2025b) are pointers to related binaries work, a known Local Group system, and a Coma-cluster confirmation; none carries a central premise or imports a uniqueness theorem, so they are not load-bearing. A non-circular reproducibility concern should be flagged: the abstract labels the minor-infall estimate an 'upper bound' and the major-infall estimate a 'lower bound,' which reverses the Sect. 4 statement that minor systematically underestimates and major overestimates the true dispersion, and the quoted debiased M81 values (180, 142, 99 km/s; Eqs. 63-65) do not follow from the stated m_sigma,b_sigma fits applied to the raw dispersions (96, 564, 102 km/s; Eqs. 60-62). This is an internal consistency/correctness problem, not a circularity, because the claimed values are not equivalent by construction to the fitted inputs.

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

All derivations are analytic; no invented entities are introduced. The free parameters are calibration constants or selection thresholds used only in the M81 application. The simulation-based axioms are domain assumptions, not standard math.

free parameters (5)
  • m_sigma_minor, b_sigma_minor = 0.53, 22.21 km/s
    Linear fit between minor-infall velocity dispersion and true dispersion for 281 M81-like Illustris-3 halos (Sect. 5.2); used to convert the observed M81 minor dispersion of 96 km/s into the quoted 180 km/s.
  • m_sigma_major, b_sigma_major = 4.01, 254.60 km/s
    Linear fit for major-infall dispersion, used to convert the observed 564 km/s into 142 km/s.
  • m_sigma_delta, b_sigma_delta = 1.03, 37.31 km/s
    Linear fit for Eq. (46) dispersion, used to convert 102 km/s into 99 km/s.
  • major-infall velocity cutoff = 3000 km/s
    Subhalos with major-infall velocity magnitude above 3000 km/s are excluded from the dispersion fit (about 2% of bound subhalos); the threshold is chosen by hand.
  • M81-like halo selection thresholds = m_halo in [0.5,5.0]e12 M_sun, at least 6 subhalos, offset up to 100 kpc, observer distance 3.7 Mpc, relative velocity…
    Chosen to mimic M81-group properties; not fitted to data but tuning the calibration sample.
assumptions (5)
  • standard math Euclidean vector geometry and standard trigonometric projections are valid for the relative positions and velocities of galaxies.
    Used throughout Sect. 2 to derive Eqs. (22)-(27).
  • domain assumption Galaxies and subhalos move non-relativistically, so the group center-of-mass velocity can be defined as in Eq. (47).
    Invoked in Sect. 3 to define the center of mass and angular momentum.
  • domain assumption The Illustris-3 simulation at z=0 is a representative sample of cosmic structures for quantifying the perpendicular and tangential velocity components.
    Basis for all percentages and dispersion fits in Sect. 4 and 5.
  • domain assumption The observer can be placed at the origin of the Illustris-3 snapshot as a random position.
    Stated in Sect. 4: 'we assume that the origin of the simulation is a random position in the snapshot'.
  • ad hoc to paper The selected M81-like halos are representative of the real M81 group despite its merging nature.
    The M81 prediction relies on this; the paper itself notes the simulated structures 'may not fully represent the characteristics of the M81-group'.

how reviews work

0 comments
Cite this review

Pith. "Pith review of Galaxy infall models for arbitrary velocity directions." pith.science (2026). https://pith.science/paper/Z4ZUNG3W

@misc{pith2026250113149,
  author       = {Pith},
  title        = {Pith review of: Galaxy infall models for arbitrary velocity directions},
  year         = {2026},
  howpublished = {\url{https://pith.science/paper/Z4ZUNG3W}},
  note         = {Machine review of arXiv:2501.13149}
}
abstract

For most galaxies in the cosmos, our knowledge of their motion is limited to line-of-sight velocities from redshift observations. To determine the radial velocity between two galaxies the minor and major infall models were established by Karachentsev & Kashibadze (2006). Regardless of the background cosmology, our derivations reveal that these infall models approximate the total radial velocity between two galaxies by two different projections employing different information about the system. For galaxies having small angular separations $\theta$, all infall models agree that the radial velocity is the difference of their line-of-sight components. Applying these models to ca. $500$ halos of the Illustris-3 simulation, we find the perpendicular and tangential velocity parts to be non-negligible for more than 90% of all, more than 5000 infalling subhalos. Thus, even for $\theta < 10$ deg, the infall-model velocities deviate from the true radial velocity. Only for 30% we found the true one lay between the minor and major infall velocity. However, the infall models yield robust upper and lower bounds to the true radial velocity dispersion. Observed under $\theta < 10$ deg the velocity dispersion inferred from the sole difference of line-of-sight velocity components even coincides with the true one, justifying this approach for high-redshift groups and clusters. Based on these findings, we predict the radial velocity dispersion of the M81-group from the minor infall model (upper bound) $\sigma_{\mathrm{r,min}} = (180 \pm 42)~\mbox{km}/\mbox{s}$, from the major infall model (lower bound) $\sigma_{\mathrm{r,maj}} = (142 \pm 64) ~\mbox{km}/\mbox{s}$ and $\sigma_\mathrm{r,\Delta v} = (99 \pm 36)~\mbox{km}/\mbox{s}$ from the line-of-sight-velocity difference.

Figures

Figures reproduced from arXiv: 2501.13149 by the authors.

Figure 1
Figure 1. Three-dimensional motion of two galaxies and definition of no￾tations. Maximum information measurable for a distant observer are velocity components along the line of sight vl1, vl2 to high precision via spectroscopy, highly precise angle between the galaxy positions on the sky, θ, and line-of-sight distances r1, r2 with a precision depending on the probe used, see, Tully et al. (2023) for recent examples. with resp… view at source ↗
Figure 2
Figure 2. Minor infall model: the line-of-sight velocity components of both galaxies are projected onto their connection line. The difference of these projections yields the relative radial velocity. For vi ≈ vli , i = 1, 2, meaning v⊥i ≈ 0, we find that Eq. (26) is reduced to the first term which consists of observable quan￾tities up to the unknown direction of rˆ⊥21. So it is impossible to calculate vt in general, which exp… view at source ↗
Figure 3
Figure 3. Major infall model for galaxy 1: the radial infall velocity of galaxy 1 onto galaxy 2 is determined from the projection of the radial infall velocity and the line-of-sight velocity of galaxy 2 onto the line￾of-sight of galaxy 1. An analogous procedure yields the major infall model for galaxy 2. Due to the asymmetry of this model, both radial infall velocities need not be of the same size. A special case is |vt | = 0… view at source ↗
Figures from the paper (8 more)
Figure 4
Figure 4. Figure 4: Physical distances from an observer at the origin to the centre of mass of 344 isolated, relaxed halos versus their halo masses in the z = 0-snapshot of Illustris-3. In the notation of Sect. 3, |rhalo| ≡ |rcm|. the halos and subhalos in addition to the position of the …
Figure 5
Figure 5. Figure 5: Left: Reconstructed infall velocities by Eqs. (34), (37), and (46) for all subhalos (bound in dark colours, Hubble-flow subhalos in light colours) onto their parent-halo centre versus the true radial velocity by Eq. (22). Linear fits with 1-σ confidence bounds to the p…
Figure 6
Figure 6. Figure 6: Left: Radial velocity of all 5036 subhalos onto their parent halo versus the mass of their parent halo, highlighted in blue are those subhalos whose radial velocity lies between the minor and major infall velocity (dark colours mark bound halos, light colours mark subh…
Figure 7
Figure 7. Figure 7: Velocity dispersions of bound subhalos for halos containing at least 5 bound subhalos j = 1, ..., 109, calculated based on the minor and major infall models, as well as the infall velocity approximated by Eq. (46). of a subhalo and its parent halo mass or the physical …
Figure 8
Figure 8. Figure 8: Left: Difference between the centre of mass of the parent halo and the centre of mass of the bound subhalos calculated as the mass-weighted sum of all their centre-of-mass positions versus the number of bound subhalos. The difference in the centre-of-mass positions is …
Figure 9
Figure 9. Figure 9: Same as [PITH_FULL_IMAGE:figures/full_fig_p009_9.png]
Figure 10
Figure 10. Figure 10: Left: Infall-model velocities defined in Eqs. (34), (37), and (46) for each member of the M81-group (see Table A.1 for details on the data). Centre: Velocity dispersions of the infall models and the approximation of Eq. (46) of the bound subhalos in the simulation set…
Figure 11
Figure 11. Figure 11: Summary of all results: conditions to apply the infall models, their formulae, relations, and accuracy. ity is to investigate if observations of tangential velocity compo￾nents projected on the sky can alleviate the deviations or whether it is necessary to include sat…

Discussion (0). Continue with ORCID to comment.

Reference graph

Works this paper leans on

25 extracted references · 20 canonical work pages

  1. [1]

    k., Cea, P., Chingangbam, P., et al

    Aluri, P. k., Cea, P., Chingangbam, P., et al. 2023, Classical and Quantum Grav- ity, 40, 094001

    work page 2023

  2. [2]

    Line-of-Sight Velocity Projection Impact on the Local Group Mass

    Benisty, D. & Mota, D. 2025, forthcoming in A&A, arXiv:2504.16991

    work page Pith review arXiv 2025

  3. [3]

    W., et al

    Benisty, D., Vasiliev, E., Evans, N. W., et al. 2022, ApJ, 928, L5

    2022

  4. [4]

    2025b, submitted to ApJ, arXiv:2504.04135

    Benisty, D., Wagner, J., Haridasu, S., & Salucci, P. 2025b, submitted to ApJ, arXiv:2504.04135

    arXiv

  5. [5]

    A., Tully, R

    Chiboucas, K., Jacobs, B. A., Tully, R. B., & Karachentsev, I. D. 2013, AJ, 146, 126 DESI Collaboration. 2024, AJ, 168, 58

    work page 2013

  6. [6]

    D., Koposov, S

    Diaz, J. D., Koposov, S. E., Irwin, M., Belokurov, V ., & Evans, N. W. 2014, MNRAS, 443, 1688

    work page 2014

  7. [7]

    Ellis, G. F. R., Nel, S. D., Maartens, R., Stoeger, W. R., & Whitman, A. P. 1985, Phys. Rep., 124, 315

    work page 1985

  8. [8]

    1969, MNRAS, 142, 129

    Hawking, S. 1969, MNRAS, 142, 129

    work page 1969

Show all 25 references
  1. [9]

    Karachentsev, I. D. & Kashibadze, O. G. 2006, Astrophysics, 49, 3

    2006

  2. [10]

    D., Kashibadze, O

    Karachentsev, I. D., Kashibadze, O. G., Makarov, D. I., & Tully, R. B. 2009, Mon. Not. Roy. Astron. Soc., 393, 1265

    2009

  3. [11]

    Karachentsev, I. D. & Makarov, D. A. 1996, AJ, 111, 794

    1996

  4. [12]

    D., Makarov, D

    Karachentsev, I. D., Makarov, D. I., & Kaisina, E. I. 2013, AJ, 145, 101

    2013

  5. [13]

    Karachentsev, I. D. & Nasonova, O. G. 2010, MNRAS, 405, 1075

    2010

  6. [14]

    J., Kang, J., Lee, M

    Kim, Y . J., Kang, J., Lee, M. G., & Jang, I. S. 2020, ApJ, 905, 104

    2020

  7. [15]

    Maartens, R., Santiago, J., Clarkson, C., Kalbouneh, B., & Marinoni, C. 2024, J. Cosmology Astropart. Phys., 2024, 070 Müller, O., Heesters, N., Pawlowski, M. S., et al. 2024, A&A, 683, A250

    2024

  8. [16]

    2015, Astronomy and Computing, 13, 12 Peñarrubia, J., Ma, Y .-Z., Walker, M

    Nelson, D., Pillepich, A., Genel, S., et al. 2015, Astronomy and Computing, 13, 12 Peñarrubia, J., Ma, Y .-Z., Walker, M. G., & McConnachie, A. 2014, MNRAS, 443, 2204

    2015

  9. [17]

    & de Freitas Pacheco, J

    Peirani, S. & de Freitas Pacheco, J. A. 2006, New A, 11, 325

    2006

  10. [18]

    M., Pontzen, A., Peiris, H

    Saadeh, D., Feeney, S. M., Pontzen, A., Peiris, H. V ., & McEwen, J. D. 2016, Phys. Rev. Lett., 117, 131302

    2016

  11. [19]

    2024, arXiv e-prints, arXiv:2408.13842

    Said, K., Howlett, C., Davis, T., et al. 2024, arXiv e-prints, arXiv:2408.13842

    2024 arXiv

  12. [20]

    B., Ibata, R., Reylé, C., et al

    Salomon, J. B., Ibata, R., Reylé, C., et al. 2021, MNRAS, 507, 2592

    2021

  13. [21]

    T., Anderson, J., & van der Marel, R

    Sohn, S. T., Anderson, J., & van der Marel, R. P. 2012, ApJ, 753, 7

    2012

  14. [22]

    G., Gottlöber, S., Hoffman, Y ., & Yepes, G

    Sorce, J. G., Gottlöber, S., Hoffman, Y ., & Yepes, G. 2016, MNRAS, 460, 2015

    2016

  15. [23]

    B., Kourkchi, E., Courtois, H

    Tully, R. B., Kourkchi, E., Courtois, H. M., et al. 2023, ApJ, 944, 94

    2023

  16. [24]

    I., Pomarède, D., et al

    Valade, A., Libeskind, N. I., Pomarède, D., et al. 2024, Nature Astronomy van der Marel, R. P., Fardal, M., Besla, G., et al. 2012, ApJ, 753, 8 van der Marel, R. P., Fardal, M. A., Sohn, S. T., et al. 2019, ApJ, 872, 24 V ogelsberger, M., Genel, S., Springel, V ., et al. 2014,...

    2024

  17. [25]

    & Springel, V

    Zjupa, J. & Springel, V . 2017, MNRAS, 466, 1625 Article number, page 12 Jenny Wagner and David Benisty: Galaxy infall models for arbitrary velocity directions Appendix A: Observational data set The data shown in Table A.1 is taken from Müller et al. (2024) except for the entr...

    2024

Pith tools

Reviewed August 10, 2026 · model on record in the stance chip above.