A new class of dark matter-free dwarf galaxies? I. Clues from FCC 224, NGC 1052-DF2 and NGC 1052-DF4

Aaron J. Romanowsky; Anna Ferr\'e-Mateu; Duncan A. Forbes; Jean P. Brodie; Jonah S. Gannon; Lucas M. Valenzuela; Lydia Haacke; Maria Luisa Buzzo; Michael Hilker; Steven R. Janssens

REVIEW 2 major objections 5 minor 1 cited by

A new class of dark matter-free dwarf galaxies? I. Clues from FCC 224, NGC 1052-DF2 and NGC 1052-DF4

T0 review · 2 major / 5 minor · reviewed 2026-08-08 · deepseek-v4-flash

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Pith's one-line read FCC 224 is a third dark-matter-deficient dwarf galaxy, kinematically consistent with no dark matter within one effective radius.

desk verdict FCC 224's DM-free status hinges on a broadening correction nearly as large as the measured signal, but the measurement is new, the analysis is honest and careful, and the paper deserves referee time. read the letter →

arxiv 2502.05405 v1 pith:UBW7AOD3 submitted 2025-02-08 astro-ph.GA

Maria Luisa Buzzo , Duncan A. Forbes , Aaron J. Romanowsky , Lydia Haacke , Jonah S. Gannon , Yimeng Tang , Michael Hilker , Anna Ferré-Mateu

show 3 more authors

Steven R. Janssens Jean P. Brodie Lucas M. Valenzuela

This is my paper · ORCID

classification astro-ph.GA

keywords darkmatter-deficientgalaxiesultra-diffuseglobularclustersFornaxClusterstellarkinematicsvelocitydispersiondwarfgalaxyformationLambdaCDM

topics Dark Matter

open problems Dark Matter

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 aims to establish that FCC 224, an ultra-diffuse galaxy on the outskirts of the Fornax Cluster, contains little or no dark matter, making it the third such galaxy after NGC 1052-DF2 and NGC 1052-DF4. Its stellar velocity dispersion of $\sigma_{\mathrm{stars}} = 7.82^{+6.74}_{-4.36}$ km/s is far below the $25 \pm 4$ km/s expected from the stellar mass–halo mass relation for a dwarf of its stellar mass, and the dynamical mass within one effective radius matches the stellar mass. The paper further argues that FCC 224 and the two NGC 1052 dwarfs share six unusual traits, including slow prolate rotation, quiescence in a low-density environment, coeval stars and globular clusters, flat stellar population gradients, a top-heavy globular cluster luminosity function, and monochromatic globular clusters. A sympathetic reader would care because these galaxies challenge the usual assumption that every dwarf is embedded in a massive dark halo, and because the shared traits offer a practical way to find more examples.

What carries the argument

The load-bearing comparison is between two predicted velocity dispersions for FCC 224: one from the stars alone (the no-dark-matter model) and one from the stellar mass–halo mass relation with an NFW halo (the normal model), both computed by solving the Jeans equation as in Wasserman et al. (2018). The argument subtracts an intrinsic stellar line broadening estimated from the Carney et al. (2008) metallicity–broadening relation, and it uses the Wolf et al. (2010) mass estimator to convert dispersions into enclosed masses. Around this dynamical core, the paper constructs a six-trait diagnostic framework intended to identify further members of the proposed class.

What would settle it

Measure a tip-of-the-red-giant-branch distance to FCC 224 with deep HST imaging; if the distance falls near 12.5 Mpc, the globular cluster luminosity function becomes normal and the dynamical mass could accommodate a dark-matter-dominated halo. Alternatively, high signal-to-noise spectra of individual red giants in FCC 224 would directly measure the intrinsic broadening currently subtracted from the integrated dispersion.

Watch

Extended reading notes

Core claim

On the paper's own terms, the discovery is that FCC 224 is dynamically consistent with having essentially no dark matter within one effective radius. The measured stellar velocity dispersion, after subtracting an estimated intrinsic broadening of $6.9 \pm 2.6$ km/s, is $7.82^{+6.74}_{-4.36}$ km/s, while a normal halo predicted from the stellar mass–halo mass relation would give about $25 \pm 4$ km/s. Converting the stellar and globular-cluster dispersions to enclosed masses with the Wolf et al. (2010) estimator gives $\log(M_{\mathrm{dyn}}/M_\odot) \approx 7.9 \pm 0.4$ from stars and $7.5 \pm 0.7$ from globular clusters, consistent with the stellar mass within one effective radius of $\log(M_\star/M_\odot) = 7.94 \pm 0.04$. The authors conclude that FCC 224 belongs with DF2 and DF4 in a new class of dark-matter-deficient dwarf galaxies defined by six shared traits.

Load-bearing premise

The no-dark-matter conclusion holds only if FCC 224 is really at about 20 Mpc and if the assumed intrinsic stellar broadening of $6.9 \pm 2.6$ km/s is not under-subtracted; a shorter distance or a larger broadening would leave room for a normal dark matter halo.

Editorial extensions

If this is right

If FCC 224 is truly dark-matter-deficient, such galaxies are not a quirk of the NGC 1052 group, and they occur in at least two different environments.
The six shared traits provide a photometric and spectroscopic checklist that can be used to find additional dark-matter-deficient dwarf candidates in wide surveys.
Formation models must explain the combination of no dark matter, overluminous globular clusters, and slow prolate rotation; the bullet-dwarf collision scenario is currently the only model that predicts such galaxies, though it does not yet reproduce the prolate rotation.
The likely companion FCC 240 shares the distance and stellar populations of FCC 224, and follow-up spectroscopy can test whether the two formed together.

Reading between the lines

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

Beyond the paper, the distance is the main lever on the entire class, so every new candidate should be checked with a distance indicator independent of the Hubble flow; a closer distance weakens both the dynamical and the globular-cluster arguments.
Beyond the paper, the six-trait checklist could be applied to large samples of quiescent ultra-diffuse galaxies to estimate how common this class is, turning the bullet-dwarf collision rate into a testable prediction.
Beyond the paper, spectroscopy extending beyond 0.4 effective radii would test whether the flat stellar population gradients are real or a product of the limited field, and would clarify whether the galaxy is truly prolate rather than triaxial.
Beyond the paper, if FCC 224 is on first infall, its quiescence requires pre-processing, making it a test bed for mechanisms that quench dwarf galaxies before they enter a cluster.

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Editorial analysis

A structured set of objections, weighed in public.

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

Desk Editor's Note

read the letter

The one thing you should know: this paper reports the first spectroscopic dynamical measurement of FCC 224, and it is a genuine, carefully made measurement. If the classification holds, the DM-deficient dwarf phenomenon extends beyond the NGC 1052 group, which is a real step for the field. But the 'DM-free' label is not established by these data. It rests on two external assumptions, and either one can move the conclusion.

The measured stellar dispersion is 10.43 ± 5.76 km/s, which is below the red-arm instrumental resolution of 12.4 km/s. The paper subtracts an estimated 6.9 ± 2.6 km/s of intrinsic stellar broadening, taken from Carney et al. (2008) and applied to integrated light without adjustment, yielding a final 7.82 km/s—a value nearly identical to the correction itself. Before subtraction, the same measurement implies log(Mdyn/Msun) ≈ 8.3 and about 55% dark matter within 1 Re. Only after the correction does FCC 224 land on the no-DM line. Lower the broadening by 2 km/s and the inferred DM fraction rises to roughly 40%. Shift the adopted 20 Mpc distance to ~12.5 Mpc and the galaxy looks normal. The paper states both caveats openly; the candor does not reduce the sensitivity.

Credit where it is earned: the sky subtraction and line-spread-function work are unusually careful, the MCMC prior discussion is thoughtful and validated against DF2/DF4, and the environment analysis—an old quiescent dwarf at 1.8 R200, sitting 4σ off the age–radius relation—is a solid independent contribution. The six-trait framework is a useful organizing device for finding more candidates, and the authors flag the weak spots rather than hiding them.

The soft spots are proportionate to the claim. The GC dispersion is explicitly an upper limit and independently constrains little. The class claim rests on three objects, one of which lacks its own rotation measurement. The abstract presents the DM-free conclusion as a result, which is stronger than the evidence supports.

One nuance in the paper's favor: even the raw 10.43 km/s sits about 2.5σ below the 25 ± 4 km/s SMHM expectation. So the qualitative finding—an unusually cold, DM-poor dwarf—has legs even if the zero-DM interpretation does not survive better data. I agree with the conditional verdict, and the subtraction arithmetic checks out.

This paper deserves a serious referee. The referee's main job is to push on whether the Carney relation can be applied to integrated light without adjustment, and on the distance. It is for observers working on dwarf kinematics and UDGs, and for theorists testing formation scenarios. I would read it, and I would wait for the distance follow-up before building on the classification.

Referee Report

2 major / 5 minor

Summary. The paper presents Keck/KCWI spectroscopy of FCC 224, a quiescent ultra-diffuse galaxy in the outskirts of the Fornax Cluster, to measure its stellar and globular-cluster (GC) kinematics, stellar populations, and rotation. After subtracting an assumed intrinsic stellar broadening of 6.9 ± 2.6 km/s from a measured integrated velocity dispersion of 10.43 ± 5.76 km/s, the authors obtain a stellar dispersion of 7.82 +6.74/−4.36 km/s, which is consistent with their no-dark-matter prediction (~7.8 ± 2.0 km/s) and far below the 25 ± 4 km/s expected from a stellar mass–halo mass relation. The GC velocity dispersion is also measured but is adopted as an upper limit. From these kinematics, the authors infer log(M_dyn/M_sun) ≈ 7.9 ± 0.4 within 1 Re from stars and ≈ 7.5 ± 0.7 from GCs, compared to the stellar mass log(M_star/M_sun) ≈ 7.94 ± 0.04, implying little or no dark matter inside that radius. The paper further argues that FCC 224 shares six traits with NGC 1052-DF2 and NGC 1052-DF4 (slow prolate rotation, quiescence in low-density environments, coeval stars and GCs, flat stellar population gradients, top-heavy GC luminosity function, and monochromatic GCs), which together define a new class of dark-matter-deficient dwarf galaxies.

Significance. If the central claim holds, the paper is significant: it would establish FCC 224 as a third dark-matter-deficient dwarf outside the NGC 1052 group, weakening the idea that such galaxies are unique to a single group and supporting the existence of a class with a common formation mechanism. The analysis is careful in many respects: the data reduction, sky subtraction, spectral fitting, and discussion of priors for the GC dynamics are detailed, and the paper is explicit about the assumptions in the intrinsic-broadening correction and the distance. The paper also states its limitations (e.g., the GC dispersion being an upper limit, the distance sensitivity) in the text. However, the significance is tempered by the fact that the two load-bearing inputs—the assumed intrinsic stellar broadening and the 20 Mpc distance—carry uncertainties comparable to the signal, as detailed in the major comments. The diagnostic framework proposed for identifying additional candidates is potentially useful, but its value depends on the robustness of the FCC 224 dark-matter-deficient classification.

major comments (2)

[§3.3.1, Eq. (1)] The central DM-deficient classification of FCC 224 rests on the quadrature subtraction in Eq. (1): the measured σ_galaxy = 10.43 ± 5.76 km/s is corrected for an assumed intrinsic stellar broadening σ_broadening = 6.9 ± 2.6 km/s (from the Carney et al. 2008 relation) to yield σ_stars = 7.82 +6.74/−4.36 km/s. This is not a minor correction: the adopted broadening is nearly as large as the final quoted dispersion, and the measurement itself is below the instrumental resolution (σ_inst = 12.4 km/s). Propagating only the 1σ uncertainty in the broadening changes σ_stars from about 4.3 to 9.5 km/s, which spans a large range in inferred dark matter fraction (from ~0% to ~50% within 1 Re). The paper lists the assumptions behind applying the Carney relation (single burst, random orientations, no gradients) but does not quantify the sensitivity of the conclusion to plausible violations of these assumptions. I recommend adding a robustness test that varies σ_broadening across the full allowed range (or treats it as a free parameter in the spectral fit) and that reports the resulting DM fraction; this is needed to support the strong claim that FCC 224 is DM-deficient.
[§3.3.2 (paragraph after Eq. 3)] The dynamical mass and DM fraction quoted for FCC 224 assume a distance of 20 Mpc, yet the SBF distance is 18.6 ± 2.7 Mpc (Tang et al. 2025a), and the paper itself notes that at 12.5 Mpc the GCLF would be normal and the dynamics could accommodate a dark halo. Because the dynamical mass scales as σ² R_e (hence ∝ distance) while the stellar mass scales as distance², the inferred M_dyn/M_star ratio within 1 Re is inversely proportional to distance; a 2σ decrease in distance raises the DM fraction to roughly 40% or more even before considering the broadening uncertainty. The current presentation shows only the 20 Mpc case. I request a quantitative analysis (e.g., a plot of M_dyn/M_star and the predicted σ from the SMHM relation versus distance over the range ~12–25 Mpc) to demonstrate whether the DM-deficient conclusion is robust to the distance uncertainty. Without this, the central claim is not yet fully supported.

minor comments (5)

[§3.3.2, Eq. (2)] The likelihood expression in Eq. (2) appears to be missing a factor of 1/2 in front of the log term and an overall factor; please check the mathematical formatting and ensure the expression is correct.
[§3.3.2 and Fig. 4] The GC velocity dispersion is explicitly adopted only as an upper limit (uniform prior), yet Fig. 4 and the text present it with error bars alongside the stellar measurement; the figure and text should state clearly that the GC point is an upper limit, since otherwise it is visually interpreted as a measurement consistent with the no-DM model.
[Abstract and Conclusions] The abstract and conclusions state that FCC 224 contains 'little or no DM' or a 'negligible DM fraction', while §3.3.2 admits a DM fraction of ~30% when the upper-limit velocity dispersion is considered; these statements should be harmonized to avoid overstating the result.
[References] The entries for Müller et al. (2019a) and (2019b) appear identical (A&A 623, A36); please verify the correct references for these two citations.
[§3.3.3] For the prolate rotation claim, please state the statistical significance of the position angle of the maximum rotation axis relative to the galaxy major axis; this is a key shared trait of the proposed class and currently appears to be asserted without an explicit significance level.

Circularity Check

0 steps flagged · score 0.0 of 10

No significant circularity: the DM-free classification of FCC 224 rests on measured kinematics compared with externally calibrated models, not on an input that already contains the conclusion.

full rationale

The derivation chain is self-contained and does not reduce to its inputs. FCC 224's DM content is inferred from a measured KCWI velocity dispersion (σ_galaxy = 10.43 ± 5.76 km/s), corrected for an externally calibrated stellar-broadening contribution (6.9 ± 2.6 km/s, Carney et al. 2008) via Eq. (1), giving σ_stars = 7.82 km/s. This is then compared with independent Jeans-model predictions: 25 ± 4 km/s from the Moster et al. (2013) SMHM relation and 7.8 ± 2.0 km/s from stars alone, and converted to Mdyn using Wolf et al. (2010). The stellar mass and distance entering the comparison come from a companion paper (Tang et al. 2025a) with overlapping authorship, but the SBF distance and photometric SED fit are independent, externally falsifiable measurements that do not assume the DM content being tested. The intrinsic-broadening correction is large relative to the signal and the result is sensitive to it, but the paper adopts a published relation rather than fitting the parameter to force the no-DM answer; this is a systematic/statistical fragility, not a circularity. The proposed 'class' traits are not used as the dynamical evidence for DM deficiency but as a post-hoc diagnostic framework, so no equation or fitted parameter is equivalent to the conclusion by construction.

Assumptions & free parameters 2 free parameters · 5 assumptions · 0 invented entities

The central DM-deficiency claim rests on an adopted distance, an empirical broadening correction, a Jeans and isotropic mass model, and a prior choice for the GC dispersion. None of these is derived in the paper; together they dominate the error budget more than the random measurement uncertainties.

free parameters (2)

Adopted distance to FCC 224 = 20 Mpc (SBF: 18.6 +/- 2.7 Mpc, Tang et al. 2025a)
Sets the physical scale for Re, stellar mass, GC luminosities, and predicted velocity dispersions; the authors note that at about 12.5 Mpc the GCLF would be normal and DM could reappear.
Intrinsic stellar broadening correction = 6.9 +/- 2.6 km/s
Estimated from the Carney et al. (2008) relation for individual metal-poor stars and subtracted in quadrature from the measured 10.43 +/- 5.76 km/s to obtain the stellar dispersion; plausible variations change the DM conclusion.

assumptions (5)

domain assumption Jeans modeling under dynamical equilibrium, spherical symmetry, and isotropic orbits (Wasserman et al. 2018 prescription)
Used to translate the measured velocity dispersion into the predicted no-DM and SMHM dispersions in Section 3.3.2; if the galaxy is out of equilibrium or anisotropic, inferred masses change.
domain assumption The Carney et al. (2008) stellar broadening relation applies to the integrated stellar population of FCC 224, with no adjustments for metallicity gradients or kinematics
Invoked in Section 3.3.1 to estimate and subtract intrinsic broadening; the authors acknowledge the extrapolation from individual stars to a composite population and assume no adjustments are needed.
domain assumption The structural parameters, stellar mass, GC luminosities, and GCLF from Tang et al. (2025a) are accurate
Re, Sersic index, stellar mass, GC photometry, and GCLF are taken from a companion paper and enter the dynamical comparison and the trait classification.
domain assumption The uniform prior in the GC velocity dispersion MCMC provides a usable upper limit, while the Jeffreys prior is rejected as biased
Section 3.3.2; the adopted GC dispersion is explicitly an upper limit and enters the mass comparison.
domain assumption The Moster et al. (2013) stellar mass-halo mass relation and an NFW profile with Dutton and Maccio concentration describe a normal dwarf at this mass
Used to predict the 25 +/- 4 km/s dispersion expected if FCC 224 has a normal DM halo; other SMHM relations are said to agree within uncertainties.

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Cite this review

Pith. "Pith review of A new class of dark matter-free dwarf galaxies? I. Clues from FCC 224, NGC 1052-DF2 and NGC 1052-DF4." pith.science (2026). https://pith.science/paper/UBW7AOD3

@misc{pith2026250205405,
  author       = {Pith},
  title        = {Pith review of: A new class of dark matter-free dwarf galaxies? I. Clues from FCC 224, NGC 1052-DF2 and NGC 1052-DF4},
  year         = {2026},
  howpublished = {\url{https://pith.science/paper/UBW7AOD3}},
  note         = {Machine review of arXiv:2502.05405}
}

abstract

The discovery of quiescent, dark matter (DM)-deficient ultra-diffuse galaxies (UDGs) with overluminous globular clusters (GCs) has challenged galaxy formation models within the Lambda Cold Dark Matter ($\Lambda$CDM) cosmological paradigm. Previously, such galaxies were only identified in the NGC 1052 group, raising the possibility that they are the result of unique, group-specific processes, and limiting their broader significance. The recent identification of FCC 224, a putative DM-deficient UDG on the outskirts of the Fornax Cluster, suggests that such galaxies are not confined to the NGC 1052 group but rather represent a broader phenomenon. We aim to investigate the DM content of FCC 224 and to explore its similarities to the DM-free dwarfs in the NGC 1052 group, DF2 and DF4, to determine whether or not it belongs to the same class of DM-deficient UDGs. We use high-resolution Keck Cosmic Web Imager (KCWI) spectroscopy to study the kinematics, stellar populations, and GC system of FCC 224, enabling direct comparisons with DF2 and DF4. We find that FCC 224 is also DM-deficient and exhibits a distinct set of traits shared with DF2 and DF4, including slow and prolate rotation, quiescence in low-density environments, coeval formation of stars and GCs, flat stellar population gradients, a top-heavy GC luminosity function, and monochromatic GCs. These shared characteristics signal the existence of a previously unrecognized class of DM-deficient dwarf galaxies. This diagnostic framework provides a means of identifying additional examples and raises new questions for galaxy formation models within $\Lambda$CDM cosmology.

Figures

Figures reproduced from arXiv: 2502.05405 by the authors.

**Figure 1.** Imaging and spectra of FCC 224 (top section) and its GCs (bottom section). Top left: HST/WFC3 F814W image, highlighting the GC candidates in red circles and background/foreground sources in blue squares. The black rectangle and inset axis show the Keck/KCWI white-light image, along with the segmentation image used to separate galaxy from sky spaxels. The orange dashed ellipse marks the effective radius of the galaxy… view at source ↗

**Figure 2.** The galaxy’s recovered mass-weighted age is [PITH_FULL_IMAGE:figures/full_fig_p004_2.png] view at source ↗

**Figure 3.** Monte Carlo Markov Chain results of fitting a maximum likelihood function to the velocities recovered for the 5 GCs around FCC 224 with the highest S/N to recover the velocity dispersion and recessional velocity of the host galaxy. The MCMC was run using a uniform prior, and returned V = 1403.8 +6.0 −7.6 km s−1 and a dispersion velocity of σGCs = 12.69+10.35 −6.49 km s−1 . This velocity dispersion is considered an… view at source ↗

Figures from the paper (3 more)

**Figure 4.** Figure 4: Constraints on the velocity dispersion and enclosed mass of FCC 224. Left: Stellar velocity dispersion of stars and GCs in FCC 224 (orange), DF2 (green) and DF4 (purple) compared to two models indicated by shades: 1) No DM within the galaxies, and 2) a normal DM halo a…

**Figure 5.** Figure 5: Star formation history of FCC 224 indicating early and fast quenching, with 90% of its stellar mass having formed only ∼ 4.5 Gyr after the Big Bang (i.e., t90 ∼ 10 Gyr) and a quenching timescale (t50 − t90) of only 2.5 Gyr. uncertainties are significant and require fur…

**Figure 6.** Figure 6: The identified signatures of DM absence in dwarf galaxies. Left column: Galaxies found to be deficient of DM within 1 Re . Middle column: Shared properties of these galaxies that are unusual and different from other dwarf galaxies. Right column: We propose that these p…

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Works this paper leans on

124 extracted references · 57 canonical work pages · cited by 1 Pith paper

[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]

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]

& Matt , S

Amard , L. & Matt , S. P. 2020, , 889, 108

2020
[4]

& Nipoti , C

Battaglia , G. & Nipoti , C. 2022, Nature Astronomy, 6, 659

2022
[5]

S., Wechsler , R

Behroozi , P. S., Wechsler , R. H., & Conroy , C. 2013, , 770, 57

2013
[6]

2020, , 903, 10

Belland , B., Kirby , E., Boylan-Kolchin , M., & Wheeler , C. 2020, , 903, 10

2020
[7]

A., Sales , L

Benavides , J. A., Sales , L. V., Abadi , M. G., et al. 2021, Nature Astronomy, 5, 1255

2021
[8]

A., Sales , L

Benavides , J. A., Sales , L. V., Abadi , M. G., et al. 2024, , 977, 169

2024

Show all 124 references

[9]

2002, in Astronomical Society of the Pacific Conference Series, Vol

Bertin , E. 2002, in Astronomical Society of the Pacific Conference Series, Vol. 281, Astronomical Data Analysis Software and Systems XI, 228

2002
[10]

2022, , 515, 4622

Bidaran , B., La Barbera , F., Pasquali , A., et al. 2022, , 515, 4622

2022
[11]

2011, , 416, 1654

Bois , M., Emsellem , E., Bournaud , F., et al. 2011, , 416, 1654

2011
[12]

L., Forbes , D

Buzzo , M. L., Forbes , D. A., Brodie , J. P., et al. 2023, , 522, 595

2023
[13]

L., Forbes , D

Buzzo , M. L., Forbes , D. A., Brodie , J. P., et al. 2022, , 517, 2231

2022
[14]

2017, , 466, 798

Cappellari , M. 2017, , 466, 798

2017
[15]

2021, , 505, L100

Cardona-Barrero , S., Battaglia , G., Di Cintio , A., Revaz , Y., & Jablonka , P. 2021, , 505, L100

2021
[16]

V., & Taibi , S

Cardona-Barrero , S., Di Cintio , A., Battaglia , G., Macci \`o , A. V., & Taibi , S. 2023, , 519, 1545

2023
[17]

& Beaulieu , S

Carignan , C. & Beaulieu , S. 1989, , 347, 760

1989
[18]

W., Gray , D

Carney , B. W., Gray , D. F., Yong , D., et al. 2008, , 135, 892

2008
[19]

2019, , 482, L99

Chowdhury , A. 2019, , 482, L99

2019
[20]

Coelho , P. R. T. 2014, , 440, 1027

2014
[21]

C \^o t \'e , S., Carignan , C., & Freeman , K. C. 2000, , 120, 3027

2000
[22]

Danieli , S., van Dokkum , P., Conroy , C., Abraham , R., & Romanowsky , A. J. 2019, , 874, L12

2019
[23]

E., Sales , L

Doppel , J. E., Sales , L. V., Navarro , J. F., et al. 2021, , 502, 1661

2021
[24]

E., Sales , L

Doppel , J. E., Sales , L. V., Nelson , D., et al. 2023, , 518, 2453

2023
[25]

A., Brinks , E., Springel , V., et al

Duc , P. A., Brinks , E., Springel , V., et al. 2000, , 120, 1238

2000
[26]

2015, , 446, 120

Duc , P.-A., Cuillandre , J.-C., Karabal , E., et al. 2015, , 446, 120

2015
[27]

M., et al

Duc , P.-A., Paudel , S., McDermid , R. M., et al. 2014, , 440, 1458

2014
[28]

C., & van Dokkum , P

Dutta Chowdhury , D., van den Bosch , F. C., & van Dokkum , P. 2019, , 877, 133

2019
[29]

Dutton , A. A. & Macci \`o , A. V. 2014, , 441, 3359

2014
[30]

& okas , E

Ebrov \'a , I. & okas , E. L. 2017, , 850, 144

2017
[31]

S., Peletier , R

Eftekhari , F. S., Peletier , R. F., Scott , N., et al. 2022, , 517, 4714

2022
[32]

2011, , 414, 888

Emsellem , E., Cappellari , M., Krajnovi \'c , D., et al. 2011, , 414, 888

2011
[33]

Emsellem , E., van der Burg , R. F. J., Fensch , J., et al. 2019, , 625, A76

2019
[34]

2019 a , , 628, A60

Fensch , J., Duc , P.-A., Boquien , M., et al. 2019 a , , 628, A60

2019
[35]

Fensch , J., van der Burg , R. F. J., Je r \'a bkov \'a , T., et al. 2019 b , , 625, A77

2019
[36]

Ferguson , H. C. 1989, , 98, 367

1989
[37]

A., et al

Ferr \'e -Mateu , A., Gannon , J., Forbes , D. A., et al. 2025, arXiv e-prints, arXiv:2501.04088

2025 arXiv
[38]

S., Forbes , D

Ferr \'e -Mateu , A., Gannon , J. S., Forbes , D. A., et al. 2023, , 526, 4735

2023
[39]

Fitzpatrick , E. L. 1999, , 111, 63

1999
[40]

Forbes , D. A. & Gannon , J. 2024, , 528, 608

2024
[41]

W., Lang , D., & Goodman , J

Foreman-Mackey , D., Hogg , D. W., Lang , D., & Goodman , J. 2013, , 125, 306

2013
[42]

S., Buzzo , M

Gannon , J. S., Buzzo , M. L., Ferr \'e -Mateu , A., et al. 2023, , 524, 2624

2023
[43]

R., Yan , R., & Tinker , J

Geha , M., Blanton , M. R., Yan , R., & Tinker , J. L. 2012, , 757, 85

2012
[44]

H., et al

Geha , M., Mao , Y.-Y., Wechsler , R. H., et al. 2024, , 976, 118

2024
[45]

Gerhard , O. E. 1993, , 265, 213

1993
[46]

2019 a , , 489, 2634

Haslbauer , M., Banik , I., Kroupa , P., & Grishunin , K. 2019 a , , 489, 2634

2019
[47]

2019 b , , 626, A47

Haslbauer , M., Dabringhausen , J., Kroupa , P., Javanmardi , B., & Banik , I. 2019 b , , 626, A47

2019
[48]

L., & Genel , S

Hegde , S., Bryan , G. L., & Genel , S. 2022, , 937, 38

2022
[49]

R., et al

Ho , N., Geha , M., Munoz , R. R., et al. 2012, , 758, 124

2012
[50]

P., Macri , L

Huchra , J. P., Macri , L. M., Masters , K. L., et al. 2012, , 199, 26

2012
[51]

M., & Dolag , K

Ivleva , A., Remus , R.-S., Valenzuela , L. M., & Dolag , K. 2024, , 687, A105

2024
[52]

A., Kaviraj , S., Martin , G., et al

Jackson , R. A., Kaviraj , S., Martin , G., et al. 2021, , 502, 1785

2021
[53]

R., Forbes , D

Janssens , S. R., Forbes , D. A., Romanowsky , A. J., et al. 2024, , 534, 783

2024
[54]

W., Blakeslee , J

Jord \'a n , A., Peng , E. W., Blakeslee , J. P., et al. 2015, , 221, 13

2015
[55]

2017, , 466, 2006

Kacharov , N., Battaglia , G., Rejkuba , M., et al. 2017, , 466, 2006

2017
[56]

2024, , 963, 37

Kado-Fong , E., Robinson , A., Nyland , K., et al. 2024, , 963, 37

2024
[57]

Koleva , M., Prugniel , P., De Rijcke , S., & Zeilinger , W. W. 2011, , 417, 1643

2011
[58]

2020, , 635, A129

Krajnovi \'c , D., Ural , U., Kuntschner , H., et al. 2020, , 635, A129

2020
[59]

2021, , 917, L15

Lee , J., Shin , E.-j., & Kim , J.-h. 2021, , 917, L15

2021
[60]

R., & Chung , E

Lee , J., Shin , E.-j., Kim , J.-h., Shapiro , P. R., & Chung , E. 2024, , 966, 72

2024
[61]

2015, , 584, A113

Lelli , F., Duc , P.-A., Brinks , E., et al. 2015, , 584, A113

2015
[62]

F., Brewer , B

Lewis , G. F., Brewer , B. J., & Wan , Z. 2020, , 491, L1

2020
[63]

E., Greco , J., et al

Li , J., Greene , J. E., Greco , J., et al. 2023, , 955, 2

2023
[64]

J., & Lewis , G

Li , Y., Brewer , B. J., & Lewis , G. 2024, , 41, e073

2024
[65]

2024, , 964, 53

Liang , J., Jiang , F., Danieli , S., Benson , A., & Hopkins , P. 2024, , 964, 53

2024
[66]

W., et al

Lim , S., C \^o t \'e , P., Peng , E. W., et al. 2020, , 899, 69

2020
[67]

W., C \^o t \'e , P., et al

Lim , S., Peng , E. W., C \^o t \'e , P., et al. 2018, , 862, 82

2018
[68]

2024, , 976, 17

Lipka , M., Thomas , J., Saglia , R., et al. 2024, , 976, 17

2024
[69]

M., Telford , R., Ferguson , H

Lotz , J. M., Telford , R., Ferguson , H. C., et al. 2001, , 552, 572

2001
[70]

V., Prats , D

Macci \`o , A. V., Prats , D. H., & Dixon , K. L. 2021, , 501, 693

2021
[71]

H., et al

Mao , Y.-Y., Geha , M., Wechsler , R. H., et al. 2024, , 976, 117

2024
[72]

F., Collins , M

Martin , N. F., Collins , M. L. M., Longeard , N., & Tollerud , E. 2018, , 859, L5

2018
[73]

W., Stefanik , R

Massarotti , A., Latham , D. W., Stefanik , R. P., & Fogel , J. 2008, , 135, 209

2008
[74]

S., et al

Moreno , J., Danieli , S., Bullock , J. S., et al. 2022, Nature Astronomy, 6, 496

2022
[75]

P., Naab , T., & White , S

Moster , B. P., Naab , T., & White , S. D. M. 2013, , 428, 3121

2013
[76]

2019 a , , 623, A36

M \"u ller , O., Famaey , B., & Zhao , H. 2019 a , , 623, A36

2019
[77]

2019 b , , 623, A36

M \"u ller , O., Famaey , B., & Zhao , H. 2019 b , , 623, A36

2019
[78]

F., Frenk , C

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

1997
[79]

2023, KCWI\_DRP: Keck Cosmic Web Imager Data Reduction Pipeline in Python , Astrophysics Source Code Library, record ascl:2301.019

Neill , D., Matuszewski , M., Martin , C., Brodheim , M., & Rizzi , L. 2023, KCWI\_DRP: Keck Cosmic Web Imager Data Reduction Pipeline in Python , Astrophysics Source Code Library, record ascl:2301.019

2023
[80]

2018, , 863, L17

Nusser , A. 2018, , 863, L17

2018
[81]

2018, , 480, L106

Ogiya , G. 2018, , 480, L106

2018
[82]

C., & Burkert , A

Ogiya , G., van den Bosch , F. C., & Burkert , A. 2022, , 510, 2724

2022
[83]

& Mori , M

Otaki , K. & Mori , M. 2023, , 525, 2535

2023
[84]

B., Kaplinghat , M., Kirby , E., et al

Pace , A. B., Kaplinghat , M., Kirby , E., et al. 2020, , 495, 3022

2020
[85]

1996, , 281, 27

Persic , M., Salucci , P., & Stel , F. 1996, , 281, 27

1996
[86]

2018, , 474, 580

Ploeckinger , S., Sharma , K., Schaye , J., et al. 2018, , 474, 580

2018
[87]

J., van der Burg , R

Prole , D. J., van der Burg , R. F. J., Hilker , M., & Davies , J. I. 2019, , 488, 2143

2019
[88]

A., Iodice , E., Napolitano , N

Raj , M. A., Iodice , E., Napolitano , N. R., et al. 2020, , 640, A137

2020
[89]

2017, , 843, 128

Rhee , J., Smith , R., Choi , H., et al. 2017, , 843, 128

2017
[90]

J., Cabrera , E., & Janssens , S

Romanowsky , A. J., Cabrera , E., & Janssens , S. R. 2024, Research Notes of the American Astronomical Society, 8, 202

2024
[91]

F., Aguerri , J

Romero-G \'o mez , J., Peletier , R. F., Aguerri , J. A. L., et al. 2023, , 522, 130

2023
[92]

2024, arXiv e-prints, arXiv:2405.13500

Saifollahi , T., Voggel , K., Lan c on , A., et al. 2024, arXiv e-prints, arXiv:2405.13500

2024
[93]

Schlafly , E. F. & Finkbeiner , D. P. 2011, , 737, 103

2011
[94]

2018, , 480, 4636

Schulze , F., Remus , R.-S., Dolag , K., et al. 2018, , 480, 4636

2018
[95]

S., Peletier , R

Scott , N., Eftekhari , F. S., Peletier , R. F., et al. 2020, , 497, 1571

2020
[96]

M., Kleiner , D., et al

Serra , P., Maccagni , F. M., Kleiner , D., et al. 2023, , 673, A146

2023
[97]

2021 a , , 914, L12

Shen , Z., Danieli , S., van Dokkum , P., et al. 2021 a , , 914, L12

2021
[98]

2021 b , , 909, 179

Shen , Z., van Dokkum , P., & Danieli , S. 2021 b , , 909, 179

2021
[99]

2023, , 957, 6

Shen , Z., van Dokkum , P., & Danieli , S. 2023, , 957, 6

2023
[100]

2020, , 899, 25

Shin , E.-j., Jung , M., Kwon , G., et al. 2020, , 899, 25

2020
[101]

2019, , 488, L24

Silk , J. 2019, , 488, L24

2019
[102]

V., Cortesi , A., Haack , R

Smith Castelli , A. V., Cortesi , A., Haack , R. F., et al. 2024, , 530, 3787

2024
[103]

T., Lilly , S

Soto , K. T., Lilly , S. J., Bacon , R., Richard , J., & Conseil , S. 2016, , 458, 3210

2016
[104]

A., Sancisi , R., van Albada , T

Swaters , R. A., Sancisi , R., van Albada , T. S., & van der Hulst , J. M. 2011, , 729, 118

2011
[105]

2017, , 470, 815

Sybilska , A., Lisker , T., Kuntschner , H., et al. 2017, , 470, 815

2017
[106]

J., Gannon , J

Tang , Y., Romanowsky , A. J., Gannon , J. S., et al. 2025 a , arXiv e-prints, arXiv:2501.10665

2025 arXiv
[107]

J., van Dokkum , P

Tang , Y., Romanowsky , A. J., van Dokkum , P. G., et al. 2025 b , , 978, 21

2025
[108]

2021, , 252, 18

Tanoglidis , D., Drlica-Wagner , A., Wei , K., et al. 2021, , 252, 18

2021
[109]

V., Lim , S., et al

Toloba , E., Sales , L. V., Lim , S., et al. 2023, , 951, 77

2023
[110]

A., Borlaff , A., et al

Trujillo , I., Beasley , M. A., Borlaff , A., et al. 2019, , 486, 1192

2019
[111]

2017, , 606, A62

Tsatsi , A., Lyubenova , M., van de Ven , G., et al. 2017, , 606, A62

2017
[112]

Valenzuela , L. M. & Remus , R.-S. 2024, , 686, A182

2024
[113]

M., Remus , R.-S., Dolag , K., & Seidel , B

Valenzuela , L. M., Remus , R.-S., Dolag , K., & Seidel , B. A. 2024, , 690, A206

2024
[114]

van Dokkum , P., Danieli , S., Abraham , R., Conroy , C., & Romanowsky , A. J. 2019, , 874, L5

2019
[115]

2018 a , , 555, 629

van Dokkum , P., Danieli , S., Cohen , Y., et al. 2018 a , , 555, 629

2018
[116]

J., & Conroy , C

van Dokkum , P., Danieli , S., Cohen , Y., Romanowsky , A. J., & Conroy , C. 2018 b , , 864, L18

2018
[117]

A., et al

van Dokkum , P., Shen , Z., Keim , M. A., et al. 2022 a , , 605, 435

2022
[118]

J., et al

van Dokkum , P., Shen , Z., Romanowsky , A. J., et al. 2022 b , , 940, L9

2022
[119]

G., Abraham , R., Merritt , A., et al

van Dokkum , P. G., Abraham , R., Merritt , A., et al. 2015, , 798, L45

2015
[120]

2015, , 449, 1177

Vazdekis , A., Coelho , P., Cassisi , S., et al. 2015, , 449, 1177

2015
[121]

J., Brodie , J., et al

Villaume , A., Romanowsky , A. J., Brodie , J., et al. 2022, , 924, 32

2022
[122]

& Peng , Y

Wang , B. & Peng , Y. 2023, , 950, L22

2023
[123]

J., Brodie , J., et al

Wasserman , A., Romanowsky , A. J., Brodie , J., et al. 2018, , 863, L15

2018
[124]

D., Bullock , J

Wolf , J., Martinez , G. D., Bullock , J. S., et al. 2010, , 406, 1220

2010

Pith tools

Reviewed August 8, 2026 · model on record in the stance chip above.

[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]

& Matt , S

Amard , L. & Matt , S. P. 2020, , 889, 108

2020

[4] [4]

& Nipoti , C

Battaglia , G. & Nipoti , C. 2022, Nature Astronomy, 6, 659

2022

[5] [5]

S., Wechsler , R

Behroozi , P. S., Wechsler , R. H., & Conroy , C. 2013, , 770, 57

2013

[6] [6]

2020, , 903, 10

Belland , B., Kirby , E., Boylan-Kolchin , M., & Wheeler , C. 2020, , 903, 10

2020

[7] [7]

A., Sales , L

Benavides , J. A., Sales , L. V., Abadi , M. G., et al. 2021, Nature Astronomy, 5, 1255

2021

[8] [8]

A., Sales , L

Benavides , J. A., Sales , L. V., Abadi , M. G., et al. 2024, , 977, 169

2024