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REVIEW 4 major objections 7 minor 188 references

Gaia membership shows NGC 2266 and NGC 2324 are relaxed clusters missing low-mass stars.

Reviewed by Pith at T0; open to challenge. T0 means a machine referee read the full paper against a public rubric. the ladder, T0–T4 →

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2026-07-31 10:37 UTC pith:47YLJLLS

load-bearing objection Solid incremental Gaia reanalysis of two known clusters; the shallow MF slopes are real enough to publish but partly undercut by the paper’s own completeness numbers. the 4 major comments →

arxiv 2607.24614 v1 pith:47YLJLLS submitted 2026-07-27 astro-ph.GA astro-ph.SR

Stellar Dynamics and Evolution of the Intermediate-Age Open Clusters NGC 2266 and NGC 2324

Cyrus Raj , D. Bisht , Ashish Raj This is my paper
classification astro-ph.GA astro-ph.SR
keywords open clustersstellar dynamicsstellar evolutionmembership determinationmass functionmass segregationGaia DR3NGC 2266
verification ladder T0 review T1 audit T2 compute T3 formal T4 reserved

The pith

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

This paper reanalyzes two intermediate-age open clusters, NGC 2266 and NGC 2324, with Gaia DR3 astrometry plus 2MASS and LAMOST data. Using unsupervised clustering, especially a Gaussian mixture model, the authors build cleaner member lists than prior catalogs and remeasure distances, ages, sizes, and internal structure. They find present-day mass-function slopes shallower than a standard initial mass function, short dynamical relaxation times relative to cluster age, and only a mild mass-segregation signal in NGC 2324. The claim is that both clusters are already dynamically evolved: low-mass stars have been preferentially lost, and Gaia-quality membership is what makes that internal evolution measurable. A sympathetic reader cares because open clusters are the main local clocks for how stellar systems age inside the Galactic disk, and cleaner members change the mass budget and evolutionary clock.

Core claim

With GMM-selected high-probability members, both clusters show present-day mass-function slopes of about 1.13 and 1.24 over roughly 0.75–2 solar masses—shallower than a Kroupa-like initial mass function—together with relaxation times of only ~8 and ~14 Myr, far shorter than their ages, so both systems are dynamically relaxed and deficient in low-mass stars.

What carries the argument

GMM membership probabilities on Gaia astrometry (RA, Dec, parallax, proper motions), with a P≥0.7 cut adopted after comparison to pyUPMASK; that cleaned sample then drives King-profile structure, isochrone ages, and the luminosity-to-mass conversion that yields the present-day mass function.

Load-bearing premise

The ages, distances, and stellar masses all rest on metallicities chosen to make the isochrones look right on the color-magnitude diagram, not on the spectroscopic metal abundances of the same members.

What would settle it

Re-derive the mass functions and ages using a metallicity fixed to the LAMOST member mean (or high-resolution spectroscopy) instead of the photometrically preferred Z, and check whether the MF slopes remain shallower than Kroupa and whether Age/TR still greatly exceeds 1.

Watch this falsifier — get emailed when new claim-graph text bears on it.

If this is right

  • Both clusters should be treated as dynamically relaxed systems when used as Galactic-disk age or abundance tracers.
  • Mass-function work on these clusters must correct for preferential low-mass loss rather than assume a pristine initial mass function.
  • GMM membership on Gaia DR3 recovers substantially more faint members than earlier DR2 catalogs, changing total mass and structural radii.
  • NGC 2324 is the better candidate of the pair for follow-up mass-segregation tests; NGC 2266 shows no significant radial mass sorting.

Where Pith is reading between the lines

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

  • If photometric metallicity remains the dominant age driver, similar intermediate-age clusters in crowded third-quadrant fields may systematically mis-estimate dynamical age until spectroscopy is folded into the isochrone prior.
  • The method comparison implies that for heavily contaminated fields, CMD coherence after clustering may be a better acceptance metric than raw member count alone.
  • Dissociation times of a few hundred Myr suggest these clusters will remain identifiable long enough for multi-epoch proper-motion and binary studies to catch ongoing evaporation.

Editorial analysis

A structured set of objections, weighed in public.

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

Referee Report

4 major / 7 minor

Summary. The authors reanalyze the intermediate-age open clusters NGC 2266 and NGC 2324 with Gaia DR3, supplemented by 2MASS and LAMOST DR7. Membership is derived with two unsupervised methods (GMM and pyUPMASK); the GMM sample (719 and 852 members at P≥0.7) is adopted after a CMD-dispersion comparison. Bailer–Jones Bayesian distances (3.55, 4.18 kpc), King-profile structural parameters, reddening from 2MASS TCDs, and PARSEC isochrone ages (1.1 Gyr, 790 Myr) at photometrically chosen metallicities are derived. The central result is a dynamical one: present-day mass-function slopes of x=1.13±0.18 and 1.24±0.19 over ~0.75–2.0 M⊙, shallower than Kroupa, combined with relaxation times of 7.9 and 14.4 Myr (τ=Age/T_R≫1), are taken to indicate dynamically evolved clusters depleted in low-mass stars. A KS test finds no significant mass segregation in NGC 2266 and a marginal hint in NGC 2324; dissociation times of ~0.4–0.5 Gyr are estimated.

Significance. If the MF result survives a proper completeness treatment, the paper would provide useful evidence that two intermediate-age outer-disk clusters are dynamically evolved, adding to the still-sparse census of PDMFs below ~1 M⊙ in this age/distance regime. The deeper membership catalogs (2 mag beyond Cantat-Gaudin 2020) and the quantitative GMM-vs-pyUPMASK comparison are genuine contributions, and the sensitivity tests on the membership probability threshold show good practice. However, the work is methodologically incremental — a standard pipeline applied to two well-studied clusters — and its scientific weight rests entirely on the faint-end MF analysis that is currently compromised. Significance is therefore moderate and conditional on the revisions above.

major comments (4)
  1. [§7.2, Fig. 15, Table 3] The headline MF slopes are fitted over 0.75–2.0 M⊙, but the LF/MF are stated to use only members brighter than G=19. With the adopted isochrone distance moduli (3.16/3.98 kpc) and A_G≈0.19–0.22, G=19 corresponds to M_G≈6.3, which on the adopted PARSEC isochrones (1.1 Gyr, Z=0.0084; 790 Myr, Z=0.0038) maps to ≈0.85–0.9 M⊙. Stars of 0.75–0.80 M⊙ have M_G≈7.3–8, i.e. G≈19.8–20.4 — fainter than even the G=20 limit used elsewhere. The lowest fitted mass bin(s) are therefore expected to be significantly undercounted, and incompleteness at the faint end flattens exactly the slope whose shallowness is the central result. §7.2 asserts the fit range is 'unaffected by incompleteness' but offers no demonstration (no completeness curve, no slope-vs-magnitude-cut test), and the text itself acknowledges the lowest-mass decline may be incompleteness-driven. This must be resolved: either restrict the pow
  2. [§2, §7.1, §7.2, Table 4] The completeness limit is stated inconsistently: §2 and the Introduction adopt G=20 as the completeness limit 'for membership selection and subsequent analyses, including luminosity function, mass function', while §7.1–7.2 use G=19 as the LF/MF limit, and the mass-segregation faint sample (Table 4, note) uses G≤20, reaching 0.63–0.64 M⊙ — fainter than the MF analysis itself. Related internal contradictions: §7.1 quotes absolute-magnitude ranges of −2.95≤M_G≤2.02 (NGC 2266) and −1.08≤M_G≤3.86 (NGC 2324), yet the same paragraph states the LF peaks at M_G≈4–5, outside the quoted ranges; with a G<19 cut the faint end should extend to M_G≈6.3. These numbers as printed are mutually inconsistent and make it impossible to verify which stars actually entered the LF/MF. The authors need to harmonize the magnitude limits, correct the quoted M_G ranges, and state explicitly how many stars and which
  3. [§6.2, §6.3, §7.1] The adopted metallicities (Z=0.0084, [Fe/H]=−0.35 for NGC 2266; Z=0.0038, −0.70 for NGC 2324) are chosen by visual CMD fit rather than from the LAMOST member spectroscopy, which for NGC 2266 yields ⟨[Fe/H]⟩=−0.62±0.57 dex. Age, reddening, distance modulus, and the mass–luminosity relation used for the MF are all co-adjusted within the age–metallicity–reddening–distance degeneracy, and the same CMD is then used to construct the LF/MF. Furthermore, two different distances are used in different places: isochrone distances (3.16/3.98 kpc) for the LF/MF absolute magnitudes, Bailer–Jones distances (3.55/4.18 kpc) for Galactocentric coordinates and (implicitly) the structural pc conversions — a 10–12% systematic offset that directly shifts the M_G-to-mass mapping at the faint end, compounding Major Comment 1. At minimum the authors should (i) quantify the MF slope sensitivity to the adopted Z a
  4. [§7.3, §7.4, §8] The dynamical-evolution narrative is internally strained. NGC 2266 is the older cluster with the larger τ=Age/T_R, yet shows no mass segregation (D=0.102, p=0.231), while the younger NGC 2324 shows a mild hint (p=0.077). If T_R is truly 7.9 Myr (τ>100), two-body relaxation should have produced unambiguous segregation in NGC 2266; its absence, together with a shallow PDMF that may itself be an incompleteness artifact (Major Comment 1), leaves the 'dynamically evolved' conclusion supported mainly by the short T_R estimate — which in turn depends on N, R_h, and m̄ whose mutual consistency is unclear (see minor comment on total mass). The discussion in §7.4 and §8 should explicitly address this tension rather than asserting relaxation from τ≫1 alone.
minor comments (7)
  1. [§7.4] The quoted dynamical evolution parameters do not follow from the paper's own numbers: 1.1 Gyr / 7.9 Myr = 139, not τ=153; 790 Myr / 14.4 Myr = 54.9, not 61.7. Please check the arithmetic or the T_R values. Also, the Spitzer & Hart (1971) formula is conventionally written with log10(0.4N); using natural log gives ~8 Myr for NGC 2266 — please state which convention is used.
  2. [§7.2, Table 3] Mass bookkeeping is inconsistent: 719 members at mean mass 1.43 M⊙ implies ~1030 M⊙, not the quoted total 752.91 M⊙. Presumably the total/mean mass refer to the G<19 subsample, but N in the relaxation-time formula is then ambiguous. Please define which sample enters each quantity.
  3. [Table 5] Table 5 lists distances as '3550±0.23' pc and '4180±0.24' pc; the uncertainties should be ±230 and ±240 pc (the 0.23/0.24 are in kpc).
  4. [§6.2, §6.3] §6.3: '719 evolved member stars' — 'evolved' appears to be a typo; these are all members. Also, the Z↔[Fe/H] conversion formula in §6.2 (Z = 0.013/(0.04)×10^{-(Fe/H)}) is misprinted/garbled; please give the correct expression.
  5. [§4] The parallax treatment mixes pieces: a constant −0.029 mas zero-point is applied (Lindegren et al. 2021 actually give the magnitude/color-dependent Z5), and the adopted distances are then taken from the Bailer-Jones catalog (the 2018 reference is DR2-based; for DR3 parallaxes the 2021 EDR3 geometric distances would be appropriate). The resulting distances agree with literature, so this is presentation-level, but it should be cleaned up.
  6. [Table 5, §8] Table 5 shows Selim et al. (2014) derived an MF slope of 2.68 for NGC 2266 — drastically steeper than the 1.13 found here. Given that the sign of this difference is the headline result, one paragraph discussing the origin of the discrepancy (magnitude limits, membership, mass range) is needed.
  7. [References, Fig. 4] Reference list needs a pass: Cantat-Gaudin et al. 2020a and 2020b are the same paper; the Gaia Collaboration (2020) entry is titled as Data Release 3; several in-text citations (e.g. Higuera et al. 2002, Gao 2014/2018) have reference entries whose titles do not obviously match the claims attributed to them. Also Figure 4's caption (membership probability vs G) does not match its in-text description (spatial concentration illustration).

Circularity Check

1 steps flagged

No significant circularity: standard observational OC analysis; photometric parameter co-fitting is degeneracy, not derivation-by-construction.

specific steps
  1. fitted input called prediction [§6.2–6.3 and §7.2 (metallicity/isochrone choice → MF)]
    "Although the metallicity derived from LAMOST spectroscopy provides an independent estimate, the adopted metallicity for the isochrone fitting was chosen to yield the best photometric fit to the Gaia CMD. ... The best agreement between the observed CMDs and the theoretical isochrones was obtained for Z=0.0084 ... and Z=0.0038 ... The mass distribution was obtained by converting the luminosity function into a mass function using the mass–luminosity relation derived from the best-fitting PARSEC isochrones."

    Z, age, reddening and distance modulus are co-adjusted until the isochrone matches the Gaia CMD; the same isochrones then supply the mass–luminosity map for the PDMF. This couples fitted inputs to the mass scale of the MF, a classic degeneracy. It is only weakly circular: the slope x is still a free fit to counts, not equal to the inputs by definition, and is not presented as an independent first-principles prediction.

full rationale

The paper is a conventional Gaia-based open-cluster reanalysis. Membership comes from external Gaia DR3 astrometry via GMM/pyUPMASK; distances from parallax/Bailer-Jones; structure from King fits; MF slopes from power-law fits to masses mapped via PARSEC isochrones. Nothing is predicted from a quantity that is defined as that prediction. The only mild interdependence is the usual CMD degeneracy: Z (and jointly age, AG, distance modulus) is chosen for best visual isochrone match to the same Gaia CMD later used for the LF/MF mass–luminosity mapping (§6.2–6.3, §7.2). That makes absolute masses and ages systematically coupled, but the reported MF slopes remain empirical least-squares fits to binned star counts, not forced equal to the inputs. Short TR and τ≫1 follow from N, Rh, and mean mass of the adopted members plus the isochrone age; they are consistency checks, not tautologies. Self-citations (Bisht et al.) are methodological and non-load-bearing. No uniqueness theorem, ansatz smuggling, or renamed known law. Score 1 only for the acknowledged photometric co-adjustment; central dynamical claims are not circular by construction.

Axiom & Free-Parameter Ledger

7 free parameters · 7 axioms · 0 invented entities

The scientific payload is empirical parameter estimation. Load-bearing choices are the membership probability cut, photometric metallicities and reddenings tuned to CMDs, completeness magnitude limits, PARSEC isochrones, the King model, Bailer-Jones spatial prior, and the mass–luminosity map from the same isochrones used for age. No new physical entities are postulated; dynamical conclusions inherit standard stellar-dynamics formulae (Spitzer & Hart TR; Binney & Tremaine-style tdis).

free parameters (7)
  • Membership probability threshold P≥0.7 = 0.7
    Chosen after testing 60/70/80/90% as a purity–completeness compromise; directly sets the member samples used for all downstream parameters.
  • Photometric metallicity NGC 2266 = Z=0.0084 ([Fe/H]≈−0.35)
    Selected for best visual PARSEC isochrone match to Gaia CMD rather than LAMOST mean; controls age and mass–luminosity conversion.
  • Photometric metallicity NGC 2324 = Z=0.0038 ([Fe/H]≈−0.70)
    Same CMD-driven choice; literature Z spanned 0.004–0.019.
  • E(B−V) reddening from TCD/CMD = 0.17±0.04 and 0.22±0.06 mag
    Visual ZAMS shift in 2MASS (J−H)/(J−K) and Gaia CMD color excess; enters extinction and isochrone placement.
  • Isochrone log(age) means = 9.05 and 8.90
    Means of visually acceptable log-age ranges (8.95–9.15 and 8.8–9.0) fitted to CMDs.
  • MF completeness magnitude cut = G≤19 mag
    LF/MF restricted to G≤19 (membership to G≤20) to limit incompleteness; defines fitted mass ranges.
  • Gaia parallax zero-point offset = −0.029 mas
    Global Lindegren et al. (2021) correction applied before distance inference.
axioms (7)
  • domain assumption Cluster and field stars in (position, parallax, proper motion) space are well-described as a mixture of multivariate Gaussians (GMM) or by pyUPMASK spatial random-field rejection.
    §3 bases all membership probabilities on these unsupervised models without proving Gaussianity of the field.
  • domain assumption King (1962) empirical density law describes the radial surface-density profile, yielding rc, rt, and concentration.
    §5 fits f(r)=fbg+f0(1/√(1+(r/rc)²)−1/√(1+(r/rt)²))² to build structural parameters used later in dynamics.
  • domain assumption PARSEC/COLIBRI isochrones (Marigo et al. 2017) correctly map age, Z, and extinction to Gaia CMD morphology and supply the mass–luminosity relation for the PDMF.
    §6.3 and §7.2 convert photometry to age and stellar masses via these models.
  • domain assumption Bailer-Jones et al. Bayesian distances with exponentially decreasing space-density prior are preferred over naive 1/ϖ for these parallax precisions.
    §4 adopts 3.55 and 4.18 kpc from that framework for all subsequent linear scales.
  • domain assumption Spitzer & Hart (1971) half-mass relaxation time and the Binney & Tremaine-style dissociation time formula apply with Rh from Larsen (2006) and mean mass from the MF sample.
    §7.4 computes TR and tdis and interprets τ≫1 as dynamical relaxation.
  • domain assumption Standard interstellar reddening law with E(J−H)/E(J−K)≈0.55–0.60 and AG=1.86 E(GBP−GRP).
    §6.1 converts NIR and Gaia color excesses to E(B−V) and AG.
  • standard math Expectation-maximization and related clustering mathematics are correctly implemented in the software used.
    §3 cites Dempster et al. EM and standard GMM/pyUPMASK usage.

pith-pipeline@v1.2.0-grok45-kimik3 · 34604 in / 4458 out tokens · 93220 ms · 2026-07-31T10:37:24.225834+00:00 · methodology

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read the original abstract

We present a refined astrometric and photometric analysis of the well-studied intermediate-age open clusters NGC 2266 and NGC 2324 using high-precision Gaia DR3 data, complemented by 2MASS and LAMOST DR7 catalogs. Probable cluster members are identified using unsupervised machine learning techniques. We apply both Gaussian Mixture Models (GMMs) and \texttt{pyUPMASK}. We find that the GMM-based membership sample yields a cleaner, more coherent cluster sequence in the Gaia CMDs than pyUPMASK. We identified 719 and 852 high-probability members ($P \geq 0.7$) for NGC 2266 and NGC 2324, respectively. Using the parallax method, we determine distances of 3.55 $\pm$ 0.23~kpc for NGC 2266 and 4.18 $\pm$ 0.24~kpc for NGC 2324. The radius estimates for both clusters are 7.23 $\pm$ 0.47 pc and 10.94 $\pm$ 0.63 pc. Isochrone fitting estimated ages of $1.1 \pm 0.1$~Gyr for NGC 2266 and $790 \pm 150$~Myr for NGC 2324. These age estimates were derived assuming metallicities of $Z = 0.0084$ and $Z = 0.0038$, respectively. The King profile fitting indicates that both clusters exhibit compact, well-defined radial structures. Their tidal radii are $8.84'$ (9.13 pc) for NGC 2266 and $10.97'$ (13.34 pc) for NGC 2324. The slopes of the present-day mass functions are $1.13\pm0.18$ for NGC 2266 and $1.24\pm0.19$ for NGC 2324, indicating a deficiency of low-mass stars. The derived mass-function slopes are consistent with dynamical evolution in both clusters. The clusters exhibit short relaxation times, while only NGC 2324 shows a mild indication of mass segregation. This study highlights the power of Gaia astrometry to resolve internal structures within open clusters and refine their dynamical parameters.

Figures

Figures reproduced from arXiv: 2607.24614 by Ashish Raj, Cyrus Raj, D. Bisht.

Figure 1
Figure 1. Figure 1: Identification maps of NGC 2266 and NGC 2324 obtained from the Digitized Sky Survey. The red inner circles represent the cluster radii (7 [PITH_FULL_IMAGE:figures/full_fig_p003_1.png] view at source ↗
Figure 4
Figure 4. Figure 4: To address this challenge, a VPD visually displays [PITH_FULL_IMAGE:figures/full_fig_p004_4.png] view at source ↗
Figure 3
Figure 3. Figure 3: The VPD provides a useful visual diagnostic of the [PITH_FULL_IMAGE:figures/full_fig_p004_3.png] view at source ↗
Figure 2
Figure 2. Figure 2: (a) Errors in Gaia proper motions and parallax as a function of G magnitude. (b) Photometric uncertainties in Gaia bands (G, GBP, GRP). (c) Errors in 2MASS photometry (J, H, K) vs. J magnitude [PITH_FULL_IMAGE:figures/full_fig_p005_2.png] view at source ↗
Figure 3
Figure 3. Figure 3: Top panels: Vector Point Diagrams (VPDs) showing proper motion in right ascension [PITH_FULL_IMAGE:figures/full_fig_p005_3.png] view at source ↗
Figure 4
Figure 4. Figure 4: Membership Probability as a function of G magnitude, where the green circles represent member stars with membership probabilities greater than 70% obtained using the GMM method, and the red circles represent member stars with membership probabilities greater than 70% obtained using pyUPMASK. The orange circles indicate stars with more than 70% common membership prob￾abilities, while the black circles repre… view at source ↗
Figure 5
Figure 5. Figure 5: Cluster member identification using the Gaussian Mixture Model (GMM) method for NGC 2266 (top panels) and NGC 2324 (bottom panels). The left [PITH_FULL_IMAGE:figures/full_fig_p007_5.png] view at source ↗
Figure 6
Figure 6. Figure 6: Same as Fig. 5 but using the [PITH_FULL_IMAGE:figures/full_fig_p008_6.png] view at source ↗
Figure 7
Figure 7. Figure 7: Comparison of the proper-motion and spatial distributions of cluster members for NGC 2266 (top panels) and NGC 2324 (bottom panels). The left panels [PITH_FULL_IMAGE:figures/full_fig_p010_7.png] view at source ↗
Figure 8
Figure 8. Figure 8: Comparison of the Gaia color–magnitude diagrams (CMDs) for the OCs NGC 2266 (left) and NGC 2324 (right). The panels show the CMDs ( [PITH_FULL_IMAGE:figures/full_fig_p010_8.png] view at source ↗
Figure 9
Figure 9. Figure 9: Parallax as a function of Gaia G magnitude for probable member stars of NGC 2266 (left panel) and NGC 2324 (right panel). The grey circles represent all stars in the selected cluster regions, while the black points indicate high-probability cluster members (P ≥ 0.7) identified using the GMM method. The horizontal red line marks the mean parallax value derived from the Gaussian fit to the parallax distribut… view at source ↗
Figure 10
Figure 10. Figure 10: Histograms of stellar number density along right ascension (left panels) and declination (right panels) for the clusters NGC 2266 (top row) and NGC 2324 [PITH_FULL_IMAGE:figures/full_fig_p012_10.png] view at source ↗
Figure 11
Figure 11. Figure 11: Radial surface density profiles of the OCs NGC 2266 (left panel) and NGC 2324 (right panel). The stellar surface density (stars arcmin [PITH_FULL_IMAGE:figures/full_fig_p013_11.png] view at source ↗
Figure 13
Figure 13. Figure 13: Mean G-band extinction values, AG, are 0.17 for NGC 2266 and 0.22 for NGC 2324, considering only members with probabilities over 70%. From the CMDs ((GBP − GRP) vs. G) based on Gaia Collaboration et al. (2023), we derived the distance moduli and ages of both clusters. The distance moduli yield heliocentric distances of 3.16 kpc for NGC 2266 and 3.98 kpc for NGC 2324, matching previous studies (Bailer￾Jone… view at source ↗
Figure 12
Figure 12. Figure 12: Near-infrared (J − H) versus (J − K) color–color diagrams for the OCs NGC 2266 (top panel) and NGC 2324 (bottom panel) using probable cluster members. The black circles represent the observed stellar colors from 2MASS photometry. The solid red curve denotes the intrinsic Zero-Age Main Sequence (ZAMS) adopted from Caldwell et al. (1993). The dashed red curve represents the same ZAMS shifted along the redde… view at source ↗
Figure 13
Figure 13. Figure 13: All the stars here are probable members with a probability above 70 percent. The curves are isochrones from (Marigo et al., 2017), with log ages 8.95, 9.05, [PITH_FULL_IMAGE:figures/full_fig_p015_13.png] view at source ↗
Figure 14
Figure 14. Figure 14: Luminosity functions of NGC 2266 (top) and NGC 2324 (bottom). [PITH_FULL_IMAGE:figures/full_fig_p016_14.png] view at source ↗
Figure 15
Figure 15. Figure 15: Observed stellar mass functions for the OCs NGC 2266 (top panel) [PITH_FULL_IMAGE:figures/full_fig_p017_15.png] view at source ↗
Figure 16
Figure 16. Figure 16: Normalized cumulative radial distributions of cluster members in two [PITH_FULL_IMAGE:figures/full_fig_p018_16.png] view at source ↗

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