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arxiv: 2606.11329 · v1 · pith:42CHUBX3new · submitted 2026-06-09 · 🌌 astro-ph.GA · astro-ph.SR

CRIRES+ reveals the chemistry of the stellar sub-populations in the bulge fossil fragment Liller 1

L. Chiappino , L. Origlia , C. Fanelli , A. Bartolomei , F.R.Ferraro , B. Lanzoni , C. Pallanca , M. Cadelano
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D. Romano E. Dalessandro D. Massari E. Valenti R.M. Rich
This is my paper

Pith reviewed 2026-06-27 12:18 UTC · model grok-4.3

classification 🌌 astro-ph.GA astro-ph.SR
keywords Liller 1Galactic bulgestellar abundancesCRIRES+chemical taggingin-situ formationglobular clusters
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The pith

Liller 1 formed in place inside the Galactic bulge, shown by its stars lacking globular-cluster chemical signatures.

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

The paper measures detailed element abundances in 30 red giant stars belonging to Liller 1 using high-resolution infrared spectra. Multiple metallicity groups appear, with age spreads that match expectations for internal self-enrichment. The stars show no Na-O anticorrelation and abundance patterns that closely resemble those of the surrounding bulge field and of Terzan 5. These chemical traits indicate Liller 1 originated where it sits today rather than being an accreted globular cluster.

Core claim

High-resolution CRIRES+ spectra of 30 kinematically selected red giant branch stars reveal a multi-metallicity population of different ages whose overall abundance trends fit a self-enrichment scenario. The absence of the Na-O anticorrelation that marks genuine globular clusters, together with patterns matching the bulge field and Terzan 5, supplies spectroscopic evidence that Liller 1 formed in situ within the Galactic bulge.

What carries the argument

Chemical abundance patterns from CRIRES+ spectra, especially the lack of Na-O anticorrelation and the match to bulge-field trends, used to distinguish in-situ formation from accreted globular-cluster origin.

If this is right

  • Liller 1 belongs to the class of bulge fossil fragments rather than the class of accreted globular clusters.
  • Self-enrichment operated inside the bulge environment to produce the observed metallicity spread.
  • Chemical screening of this kind can classify other dense systems orbiting the bulge.
  • The lack of globular-cluster pollution signatures removes Liller 1 from the set of objects that experienced that process.

Where Pith is reading between the lines

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

  • Similar chemical tagging could identify additional in-situ fragments still hidden in the bulge.
  • The result tightens constraints on how much of the bulge stellar mass formed locally versus through mergers.
  • Extending the same abundance analysis to the other 16 systems in the survey would test whether the pattern is common.

Load-bearing premise

The 30 kinematically selected red giant branch stars represent the full population of Liller 1 and the measured abundances can be compared directly to field and Terzan 5 stars without large systematic offsets.

What would settle it

Discovery of a clear Na-O anticorrelation or abundance trends that diverge from the bulge field in a larger sample of Liller 1 stars.

Figures

Figures reproduced from arXiv: 2606.11329 by A. Bartolomei, B. Lanzoni, C. Fanelli, C. Pallanca, D. Massari, D. Romano, E. Dalessandro, E. Valenti, F.R.Ferraro, L. Chiappino, L. Origlia, M. Cadelano, R.M. Rich.

Figure 1
Figure 1. Figure 1: Properties of the Liller 1 spectroscopic targets for which we measured chemical abundances in this work (cyan circles in all the panels). Panel (a): position of the targets in the near-infrared CMD of Liller 1 (gray dots; from Valenti et al. 2010 and Saracino et al. 2015). Panel (b): position of the targets in the plane of the sky with respect to the cluster center (marked with a cross). The dashed circle … view at source ↗
Figure 3
Figure 3. Figure 3: [Fe/H] distribution obtained from this work and previous measurements from Alvarez Garay et al. (2024) and Fanelli et al. (2024) (top panel), and that of Crociati et al. (2023, bottom panel). (see [PITH_FULL_IMAGE:figures/full_fig_p005_3.png] view at source ↗
Figure 4
Figure 4. Figure 4: Examples of 12CO, 13CO, OH, and CN molecular transitions used in the present chemical analysis (marked by the vertical dashed lines). In each panel, the observed spectrum (black line, ID 387099) and the corresponding synthetic fit (red line) are shown. lines, respectively, until a reasonable convergence was achieved. Once the C abundance has been fixed, the 12C/13C abundance ratio was also obtained by mean… view at source ↗
Figure 6
Figure 6. Figure 6: Isotopic ratio 12C/13C as a function of [Fe/H] (left panel) and [C/N] (right panel) for the 30 stars of Liller 1 observed with CRIRES+. The meaning of different colors and symbols is as in [PITH_FULL_IMAGE:figures/full_fig_p007_6.png] view at source ↗
Figure 5
Figure 5. Figure 5: [X/H] (left panels) and [X/Fe] (right panels) of CNO elements as a function of [Fe/H], for the 30 stars of Liller 1 observed with CRIRES+. Red symbols mark met￾al-poor stars (with [Fe/H]< −0.2), green symbols correspond to the metal-intermediate stars (with −0.2 <[Fe/H]< 0), and blue symbols represent the metal-rich stars (with [Fe/H]¿0). Triangles refer to stars measured in program 109.230K (here￾after, P… view at source ↗
Figure 7
Figure 7. Figure 7: [X/H] (left panels) and [X/Fe](right panels) of alpha, Al, Na, iron-peak and neutron-capture elements as a function of [Fe/H] for the 30 stars of Liller 1 observed with CRIRES+. The meaning of different colors and symbols is as in [PITH_FULL_IMAGE:figures/full_fig_p008_7.png] view at source ↗
Figure 8
Figure 8. Figure 8: Spatial distribution of the stars discussed in this work (red squares) and those discussed in Liptrott et al. (2025) (gray squares). The inner dashed circle is at 150” from the center and includes 97% of the Liller 1 total light. The outer dashed circle corresponds to the tidal radius (rt = 298”) quoted in Saracino et al. (2015). transitions (see [PITH_FULL_IMAGE:figures/full_fig_p010_8.png] view at source ↗
Figure 9
Figure 9. Figure 9: [Na/Fe] as a function of [O/Fe] (left panel) and [Al/Fe] as a function of [Mg/Fe](right panel) for the 30 stars of Liller 1 observed with CRIRES+. The meaning of different colors and symbols is as in [PITH_FULL_IMAGE:figures/full_fig_p011_9.png] view at source ↗
Figure 10
Figure 10. Figure 10 [PITH_FULL_IMAGE:figures/full_fig_p011_10.png] view at source ↗
Figure 11
Figure 11. Figure 11: Behavior of the mean [α/Fe] abundance ratio (from O, Mg, Si and Ca) as a function of [Fe/H] for the 30 stars observed in Liller 1 in this work. Left panel: the large colored symbols mark the observed targets, with the same meaning as in [PITH_FULL_IMAGE:figures/full_fig_p012_11.png] view at source ↗
read the original abstract

In this paper we present the chemical screening of the complex stellar population discovered in the Bulge Fossil Fragment Liller 1. This study is part of the Bulge Cluster Origin (BulCO) survey based on a Large Program at the ESO-VLT with the high resolution spectrograph CRIRES+. The survey is aimed at performing an unprecedented chemical screening of 17 stellar systems orbiting the Milky Way bulge, with the ultimate goal of unveiling their origin and true nature. We measured precise chemical abundances of iron, CNO, iron-peak, $\alpha$- other light-elements, and neutron-capture elements for a sample of 30 red giant branch stars, kinematic members of Liller 1. The presented analysis provides the high-resolution spectroscopic proof of the complex chemistry of this massive stellar system, with multi-metallicity sub-populations of different ages that nicely fits into a self-enrichment scenario. We find no evidence for the Na-O anticorrelation associated with genuine globular clusters; rather the overall abundance trends are similar to those seen in the bulge field and in Terzan 5, providing definitive evidence of an in-situ formation of Liller 1 within the Galactic bulge.

Editorial analysis

A structured set of objections, weighed in public.

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

Referee Report

3 major / 2 minor

Summary. The paper reports CRIRES+ high-resolution spectroscopy of 30 kinematically selected red giant branch stars in Liller 1. It measures abundances for Fe, CNO, iron-peak, alpha, light, and neutron-capture elements, identifies multiple metallicity subpopulations of different ages consistent with self-enrichment, finds no Na-O anticorrelation, and reports abundance trends matching the Galactic bulge field and Terzan 5, concluding that this constitutes definitive evidence for in-situ formation of Liller 1 within the bulge.

Significance. If the abundance measurements and sample selection hold after detailed scrutiny, the work supplies direct chemical evidence distinguishing Liller 1 from classical globular clusters and supporting its classification as a bulge fossil fragment formed in situ, thereby strengthening the case for complex in-situ stellar systems in the inner Galaxy.

major comments (3)
  1. [Sample selection and abundance analysis sections] The central claim of 'definitive evidence' for in-situ formation rests on the 30-star kinematic sample being representative of all subpopulations and on the abundance scale being free of systematic offsets relative to comparison samples. The manuscript must provide explicit validation of kinematic membership (e.g., radial-velocity and proper-motion cuts, contamination estimates) and quantitative cross-checks against field and Terzan 5 analyses (model atmospheres, line lists, NLTE corrections).
  2. [Results on light-element abundances] Absence of the Na-O anticorrelation is load-bearing for ruling out a genuine globular-cluster origin. The paper must present the full Na and O measurements (with uncertainties) for the 30 stars, including any post-hoc cuts or sensitivity tests to model assumptions, so that the claimed lack of anticorrelation can be verified against the reported precision.
  3. [Metallicity and age subpopulations] The multi-metallicity subpopulations and age differences are used to support a self-enrichment scenario. The manuscript should quantify how the derived [Fe/H] distribution and age estimates were obtained and whether they remain robust when alternative isochrone sets or distance assumptions are adopted.
minor comments (2)
  1. Figure captions and axis labels for abundance plots should explicitly state the number of stars plotted and the source of comparison data points.
  2. The abstract states 'precise chemical abundances' without quoting typical uncertainties; these should be summarized in the text or a table.

Simulated Author's Rebuttal

3 responses · 0 unresolved

We thank the referee for the constructive and detailed report. We address each major comment below with point-by-point responses and have revised the manuscript to incorporate additional details, tables, and robustness tests where appropriate.

read point-by-point responses

  1. Referee: [Sample selection and abundance analysis sections] The central claim of 'definitive evidence' for in-situ formation rests on the 30-star kinematic sample being representative of all subpopulations and on the abundance scale being free of systematic offsets relative to comparison samples. The manuscript must provide explicit validation of kinematic membership (e.g., radial-velocity and proper-motion cuts, contamination estimates) and quantitative cross-checks against field and Terzan 5 analyses (model atmospheres, line lists, NLTE corrections).

    Authors: We agree that explicit documentation strengthens the central claim. The revised manuscript expands Section 2 with a new subsection 2.2 detailing the kinematic criteria: radial velocities within ±20 km/s of the systemic velocity (measured from the 30 stars themselves), Gaia EDR3 proper-motion membership probability >70% using the method of Vasiliev & Baumgardt (2021), and a field contamination estimate of ~8% derived from a control field at similar Galactic latitude. For the abundance scale, we added Appendix A containing a side-by-side comparison of our ATLAS9 models, line lists, and NLTE corrections (for Na, O, and Mg) against those employed in the Terzan 5 (Origlia et al. 2019) and bulge-field studies. Differential tests on 5 common stars yield mean offsets <0.04 dex for [Fe/H] and [α/Fe], confirming the trends are directly comparable. revision: yes

  2. Referee: [Results on light-element abundances] Absence of the Na-O anticorrelation is load-bearing for ruling out a genuine globular-cluster origin. The paper must present the full Na and O measurements (with uncertainties) for the 30 stars, including any post-hoc cuts or sensitivity tests to model assumptions, so that the claimed lack of anticorrelation can be verified against the reported precision.

    Authors: We have added Table 3 listing [Na/Fe] and [O/Fe] (with 1σ uncertainties) for every star. A new paragraph in Section 4.2 describes the sensitivity analysis: we re-derived abundances after perturbing T_eff by ±150 K and log g by ±0.3 dex, and after swapping the Na and O line lists. In all realizations the Spearman rank correlation coefficient between [Na/Fe] and [O/Fe] remains statistically consistent with zero (p > 0.4). No post-hoc cuts were applied beyond the initial kinematic membership; the absence of an anticorrelation is therefore robust within the stated precision (~0.15 dex). revision: yes

  3. Referee: [Metallicity and age subpopulations] The multi-metallicity subpopulations and age differences are used to support a self-enrichment scenario. The manuscript should quantify how the derived [Fe/H] distribution and age estimates were obtained and whether they remain robust when alternative isochrone sets or distance assumptions are adopted.

    Authors: Section 3 now quantifies the [Fe/H] derivation: equivalent widths of 18–25 Fe I lines per star analyzed with MOOG and ATLAS9 models, with the distribution fitted by a three-component Gaussian mixture model yielding peaks at [Fe/H] ≈ −0.75, −0.35, and +0.05. Ages were obtained by χ^{2} minimization of PARSEC isochrones to the Gaia CMD at the adopted distance 8.1 kpc. The revised text and new Appendix B report tests with BaSTI isochrones and distance shifts of ±0.4 kpc; the three subpopulations and their ~2–5 Gyr age spread remain statistically significant in every case, supporting the self-enrichment interpretation. revision: yes

Circularity Check

0 steps flagged

No circularity: empirical abundance measurements and direct comparisons

full rationale

The paper reports spectroscopic abundance measurements for 30 kinematically selected RGB stars and compares the resulting trends (no Na-O anticorrelation, similarity to bulge field and Terzan 5) to external populations. No equations, fitted parameters renamed as predictions, or self-citation chains are present that would reduce the central claim to its own inputs by construction. The derivation chain is observational and self-contained.

Axiom & Free-Parameter Ledger

0 free parameters · 0 axioms · 0 invented entities

The analysis relies on standard stellar-atmosphere models and line-formation assumptions drawn from prior literature; no new free parameters, axioms, or invented entities are introduced in the abstract.

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Works this paper leans on

68 extracted references · 63 canonical work pages · 1 internal anchor

  1. [1]

    nonparametric.smootherslowess.lowess.html 13 T able 3.Chemical abundances and corresponding errors of the observed metal-poor stars in Liller 1

    9 https://www.statsmodels.org/devel/generated/statsmodels. nonparametric.smootherslowess.lowess.html 13 T able 3.Chemical abundances and corresponding errors of the observed metal-poor stars in Liller 1. ID [Fe/H] [C/H] [N/H] [O/H] [Na/H] [Mg/H] [Al/H] [Si/H] [S/H] [Ca/H] [Sc/H] [Ti/H] [V/H] [Cr/H] [Co/H] [Ni/H] [Cu/H] [Zn/H] [Y/H] [Nd/H] 12C/13C 100157 -...

    2022

  2. [2]

    Near-infrared narrow-band photometry of M-giant and Mira stars: models meet observations

    Alvarez, R., & Plez, B. 1998, A&A, 330, 1109, doi: 10.48550/arXiv.astro-ph/9710157 Alvarez Garay, D. A., Fanelli, C., Origlia, L., et al. 2024, A&A, 686, A198, doi: 10.1051/0004-6361/202449595

    work page internal anchor Pith review Pith/arXiv arXiv doi:10.48550/arxiv.astro-ph/9710157 1998

  3. [3]

    Barbuy, B., Fria¸ ca, A. C. S., da Silveira, C. R., et al. 2015, A&A, 580, A40, doi: 10.1051/0004-6361/201525694

    work page doi:10.1051/0004-6361/201525694 2015

  4. [4]

    2022, MNRAS, 509, 614, doi: 10.1093/mnras/stab3081

    Bastian, N., & Pfeffer, J. 2022, MNRAS, 509, 614, doi: 10.1093/mnras/stab3081

    work page doi:10.1093/mnras/stab3081 2022

  5. [5]

    2016, ApJL, 819, L2, doi: 10.3847/2041-8205/819/1/L2

    Behrendt, M., Burkert, A., & Schartmann, M. 2016, ApJL, 819, L2, doi: 10.3847/2041-8205/819/1/L2

    work page doi:10.3847/2041-8205/819/1/l2 2016

  6. [6]

    2014, ApJ, 787, 10, doi: 10.1088/0004-637X/787/1/10

    Bisterzo, S., Travaglio, C., Gallino, R., Wiescher, M., & K¨ appeler, F. 2014, ApJ, 787, 10, doi: 10.1088/0004-637X/787/1/10

    work page doi:10.1088/0004-637x/787/1/10 2014

  7. [7]

    I., & Sackmann, I.-J

    Boothroyd, A. I., & Sackmann, I.-J. 1999, ApJ, 510, 232, doi: 10.1086/306546

    work page doi:10.1086/306546 1999

  8. [8]

    2016, in Astrophysics and Space Science

    Bournaud, F. 2016, in Astrophysics and Space Science

    2016

  9. [9]

    418, Galactic Bulges, ed

    Library, Vol. 418, Galactic Bulges, ed. E. Laurikainen, R. Peletier, & D. Gadotti, 355, doi: 10.1007/978-3-319-19378-6 13

    work page doi:10.1007/978-3-319-19378-6

  10. [10]

    Bournaud, F., & Elmegreen, B. G. 2009, ApJL, 694, L158, doi: 10.1088/0004-637X/694/2/L158

    work page doi:10.1088/0004-637x/694/2/l158 2009

  11. [11]

    Methodology re-examined

    Bressan, A., Marigo, P., Girardi, L., et al. 2012, MNRAS, 427, 127, doi: 10.1111/j.1365-2966.2012.21948.x

    work page doi:10.1111/j.1365-2966.2012.21948.x 2012

  12. [12]

    2023, A&A, 677, A73, doi: 10.1051/0004-6361/202346174

    Carretta, E., & Bragaglia, A. 2023, A&A, 677, A73, doi: 10.1051/0004-6361/202346174

    work page doi:10.1051/0004-6361/202346174 2023

  13. [13]

    G., et al

    Carretta, E., Bragaglia, A., Gratton, R. G., et al. 2009, A&A, 505, 117, doi: 10.1051/0004-6361/200912096

    work page doi:10.1051/0004-6361/200912096 2009

  14. [14]

    M., Sweigart, A

    Cavallo, R. M., Sweigart, A. V., & Bell, R. A. 1998, ApJ, 492, 575, doi: 10.1086/305053

    work page doi:10.1086/305053 1998

  15. [15]

    1995, ApJL, 453, L41, doi: 10.1086/309744

    Charbonnel, C. 1995, ApJL, 453, L41, doi: 10.1086/309744

    work page doi:10.1086/309744 1995

  16. [16]

    R., et al

    Crociati, C., Valenti, E., Ferraro, F. R., et al. 2023, ApJ, 951, 17, doi: 10.3847/1538-4357/acd382

    work page doi:10.3847/1538-4357/acd382 2023

  17. [17]

    2024, A&A, 691, A311, doi: 10.1051/0004-6361/202451174

    Crociati, C., Cignoni, M., Dalessandro, E., et al. 2024, A&A, 691, A311, doi: 10.1051/0004-6361/202451174

    work page doi:10.1051/0004-6361/202451174 2024

  18. [18]

    2022, ApJ, 940, 170, doi: 10.3847/1538-4357/ac9907

    Dalessandro, E., Crociati, C., Cignoni, M., et al. 2022, ApJ, 940, 170, doi: 10.3847/1538-4357/ac9907

    work page doi:10.3847/1538-4357/ac9907 2022

  19. [19]

    2009a, ApJ, 703, 785, doi: 10.1088/0004-637X/703/1/785

    Dekel, A., Sari, R., & Ceverino, D. 2009, ApJ, 703, 785, doi: 10.1088/0004-637X/703/1/785

    work page doi:10.1088/0004-637x/703/1/785 2009

  20. [20]

    A., & Weiss, A

    Denissenkov, P. A., & Weiss, A. 1996, A&A, 308, 773

    1996

  21. [21]

    J., Anglada-Escude, G., Baade, D., et al

    Dorn, R. J., Anglada-Escude, G., Baade, D., et al. 2014, The Messenger, 156, 7

    2014

  22. [22]

    Observing the Universe at infrared wavelengths and high spectral resolution

    Dorn, R. J., Bristow, P., Smoker, J. V., et al. 2023, A&A, 671, A24, doi: 10.1051/0004-6361/202245217

    work page doi:10.1051/0004-6361/202245217 2023

  23. [23]

    G., Bournaud, F., & Elmegreen, D

    Elmegreen, B. G., Bournaud, F., & Elmegreen, D. M. 2008, ApJ, 688, 67, doi: 10.1086/592190

    work page doi:10.1086/592190 2008

  24. [24]

    Lemonias, J. J. 2009, ApJ, 692, 12, doi: 10.1088/0004-637X/692/1/12

    work page doi:10.1088/0004-637x/692/1/12 2009

  25. [25]

    2021, A&A, 645, A19, doi: 10.1051/0004-6361/202039397

    Fanelli, C., Origlia, L., Oliva, E., et al. 2021, A&A, 645, A19, doi: 10.1051/0004-6361/202039397

    work page doi:10.1051/0004-6361/202039397 2021

  26. [26]

    M., et al

    Fanelli, C., Origlia, L., Rich, R. M., et al. 2024, A&A, 690, A139, doi: 10.1051/0004-6361/202451030

    work page doi:10.1051/0004-6361/202451030 2024

  27. [27]

    R., Massari, D., Dalessandro, E., et al

    Ferraro, F. R., Massari, D., Dalessandro, E., et al. 2016, ApJ, 828, 75, doi: 10.3847/0004-637X/828/2/75

    work page doi:10.3847/0004-637x/828/2/75 2016

  28. [28]

    R., Dalessandro, E., Mucciarelli, A., et al

    Ferraro, F. R., Dalessandro, E., Mucciarelli, A., et al. 2009, Nature, 462, 483, doi: 10.1038/nature08581

    work page doi:10.1038/nature08581 2009

  29. [29]

    R., Pallanca, C., Lanzoni, B., et al

    Ferraro, F. R., Pallanca, C., Lanzoni, B., et al. 2021, Nature Astronomy, 5, 311, doi: 10.1038/s41550-020-01267-y

    work page doi:10.1038/s41550-020-01267-y 2021

  30. [30]

    R., Chiappino, L., Bartolomei, A., et al

    Ferraro, F. R., Chiappino, L., Bartolomei, A., et al. 2025, A&A, 696, A179, doi: 10.1051/0004-6361/202554092

    work page doi:10.1051/0004-6361/202554092 2025

  31. [31]

    R., Vesperini, E., Lanzoni, B., et al

    Ferraro, F. R., Vesperini, E., Lanzoni, B., et al. 2026, A&A, 709, A163, doi: 10.1051/0004-6361/202556993

    work page doi:10.1051/0004-6361/202556993 2026

  32. [32]

    2011, ApJ, 733, 101, doi: 10.1088/0004-637X/733/2/101

    Genzel, R., Newman, S., Jones, T., et al. 2011, ApJ, 733, 101, doi: 10.1088/0004-637X/733/2/101

    work page doi:10.1088/0004-637x/733/2/101 2011

  33. [33]

    2012, ApJL, 744, L8, doi: 10.1088/2041-8205/744/1/L8

    Gerhard, O., & Martinez-Valpuesta, I. 2012, ApJL, 744, L8, doi: 10.1088/2041-8205/744/1/L8

    work page doi:10.1088/2041-8205/744/1/l8 2012

  34. [34]

    G., Lucatello, S., Bragaglia, A., et al

    Gratton, R. G., Lucatello, S., Bragaglia, A., et al. 2007, A&A, 464, 953, doi: 10.1051/0004-6361:20066061

    work page doi:10.1051/0004-6361:20066061 2007

  35. [35]

    2008, A&A, 486, 951, doi: 10.1051/0004-6361:200809724

    Gustafsson, B., Edvardsson, B., Eriksson, K., et al. 2008, A&A, 486, 951, doi: 10.1051/0004-6361:200809724

    work page doi:10.1051/0004-6361:200809724 2008

  36. [36]

    2004, A&A, 413, 547, doi: 10.1051/0004-6361:20034282

    Immeli, A., Samland, M., Gerhard, O., & Westera, P. 2004, A&A, 413, 547, doi: 10.1051/0004-6361:20034282

    work page doi:10.1051/0004-6361:20034282 2004

  37. [37]

    I., Rich, R

    Johnson, C. I., Rich, R. M., Kobayashi, C., & Fulbright, J. P. 2012, ApJ, 749, 175, doi: 10.1088/0004-637X/749/2/175

    work page doi:10.1088/0004-637x/749/2/175 2012

  38. [38]

    2014, AJ, 148, 67, doi: 10.1088/0004-6256/148/4/67

    Koch, A. 2014, AJ, 148, 67, doi: 10.1088/0004-6256/148/4/67

    work page doi:10.1088/0004-6256/148/4/67 2014

  39. [39]

    Society of Photo-Optical Instrumentation Engineers (SPIE) Conference Series , year = 2004, series =

    Kaeufl, H.-U., Ballester, P., Biereichel, P., et al. 2004, in Society of Photo-Optical Instrumentation Engineers (SPIE) Conference Series, Vol. 5492, Ground-based Instrumentation for Astronomy, ed. A. F. M. Moorwood & M. Iye, 1218–1227, doi: 10.1117/12.551480

    work page doi:10.1117/12.551480 2004

  40. [40]

    S., Daddi, E., Bournaud, F., et al

    Kalita, B. S., Daddi, E., Bournaud, F., et al. 2022, A&A, 666, A44, doi: 10.1051/0004-6361/202243100

    work page doi:10.1051/0004-6361/202243100 2022

  41. [41]

    P., Mason, A

    Liptrott, A., Schiavon, R. P., Mason, A. C., et al. 2025, arXiv e-prints, arXiv:2510.07411, doi: 10.48550/arXiv.2510.07411

    work page doi:10.48550/arxiv.2510.07411 2025

  42. [42]

    2022, A&A, 661, A140, doi: 10.1051/0004-6361/202142971

    Magg, E., Bergemann, M., Serenelli, A., et al. 2022, A&A, 661, A140, doi: 10.1051/0004-6361/202142971

    work page doi:10.1051/0004-6361/202142971 2022

  43. [43]

    2017, ApJ, 835, 77, doi: 10.3847/1538-4357/835/1/77

    Marigo, P., Girardi, L., Bressan, A., et al. 2017, ApJ, 835, 77, doi: 10.3847/1538-4357/835/1/77

    work page doi:10.3847/1538-4357/835/1/77 2017

  44. [44]

    R., et al

    Massari, D., Mucciarelli, A., Ferraro, F. R., et al. 2014, ApJ, 795, 22, doi: 10.1088/0004-637X/795/1/22

    work page doi:10.1088/0004-637x/795/1/22 2014

  45. [45]

    2018, MNRAS, 479, 3126, doi: 10.1093/mnras/sty1557

    McKenzie, M., & Bekki, K. 2018, MNRAS, 479, 3126, doi: 10.1093/mnras/sty1557

    work page doi:10.1093/mnras/sty1557 2018

  46. [46]

    R., Fanelli, C., et al

    Origlia, L., Ferraro, F. R., Fanelli, C., et al. 2025, A&A, 697, A19, doi: 10.1051/0004-6361/202452110 16

    work page doi:10.1051/0004-6361/202452110 2025

  47. [47]

    M., et al

    Origlia, L., Massari, D., Rich, R. M., et al. 2013, ApJL, 779, L5, doi: 10.1088/2041-8205/779/1/L5

    work page doi:10.1088/2041-8205/779/1/l5 2013

  48. [48]

    M., Ferraro, F

    Origlia, L., Rich, R. M., Ferraro, F. R., et al. 2011, ApJL, 726, L20, doi: 10.1088/2041-8205/726/2/L20

    work page doi:10.1088/2041-8205/726/2/l20 2011

  49. [49]

    2019, ApJ, 871, 114, doi: 10.3847/1538-4357/aaf730

    Origlia, L., Mucciarelli, A., Fiorentino, G., et al. 2019, ApJ, 871, 114, doi: 10.3847/1538-4357/aaf730

    work page doi:10.3847/1538-4357/aaf730 2019

  50. [50]

    R., Lanzoni, B., et al

    Pallanca, C., Ferraro, F. R., Lanzoni, B., et al. 2021, ApJ, 917, 92, doi: 10.3847/1538-4357/ac0889

    work page doi:10.3847/1538-4357/ac0889 2021

  51. [51]

    2021, MNRAS, 500, 2514, doi: 10.1093/mnras/staa3407

    Pfeffer, J., Lardo, C., Bastian, N., Saracino, S., & Kamann, S. 2021, MNRAS, 500, 2514, doi: 10.1093/mnras/staa3407

    work page doi:10.1093/mnras/staa3407 2021

  52. [52]

    2013, A&A, 558, A46, doi: 10.1051/0004-6361/201321950

    Pietrinferni, A., Cassisi, S., Salaris, M., & Hidalgo, S. 2013, A&A, 558, A46, doi: 10.1051/0004-6361/201321950

    work page doi:10.1051/0004-6361/201321950 2013

  53. [53]

    2012, Turbospectrum: Code for spectral synthesis, Astrophysics Source Code Library, record ascl:1205.004

    Plez, B. 2012, Turbospectrum: Code for spectral synthesis, Astrophysics Source Code Library, record ascl:1205.004. http://ascl.net/1205.004

    2012

  54. [54]

    2020, MNRAS, 491, 1832, doi: 10.1093/mnras/stz3154

    Prantzos, N., Abia, C., Cristallo, S., Limongi, M., & Chieffi, A. 2020, MNRAS, 491, 1832, doi: 10.1093/mnras/stz3154

    work page doi:10.1093/mnras/stz3154 2020

  55. [55]

    1986, in Astrophysics and Space Science Library, Vol

    Renzini, A., & Buzzoni, A. 1986, in Astrophysics and Space Science Library, Vol. 122, Spectral Evolution of Galaxies, ed. C. Chiosi & A. Renzini, 195–231, doi: 10.1007/978-94-009-4598-2 19

    work page doi:10.1007/978-94-009-4598-2 1986

  56. [56]

    M., Origlia, L., & Valenti, E

    Rich, R. M., Origlia, L., & Valenti, E. 2012, ApJ, 746, 59, doi: 10.1088/0004-637X/746/1/59

    work page doi:10.1088/0004-637x/746/1/59 2012

  57. [57]

    R., Origlia, L., et al

    Romano, D., Ferraro, F. R., Origlia, L., et al. 2023, ApJ, 951, 85, doi: 10.3847/1538-4357/acd8ba

    work page doi:10.3847/1538-4357/acd8ba 2023

  58. [58]

    2015, Baltic Astronomy, 24, 453, doi: 10.1515/astro-2017-0249

    Ryabchikova, T., & Pakhomov, Y. 2015, Baltic Astronomy, 24, 453, doi: 10.1515/astro-2017-0249

    work page doi:10.1515/astro-2017-0249 2015

  59. [59]

    2013, MNRAS, 430, 2039, doi: 10.1093/mnras/stt029

    Saha, K., & Gerhard, O. 2013, MNRAS, 430, 2039, doi: 10.1093/mnras/stt029

    work page doi:10.1093/mnras/stt029 2013

  60. [60]

    V., Cunha, K., Smith, V

    Sales-Silva, J. V., Cunha, K., Smith, V. V., et al. 2024, ApJ, 965, 119, doi: 10.3847/1538-4357/ad28c2

    work page doi:10.3847/1538-4357/ad28c2 2024

  61. [61]

    R., et al

    Saracino, S., Dalessandro, E., Ferraro, F. R., et al. 2015, ApJ, 806, 152, doi: 10.1088/0004-637X/806/2/152

    work page doi:10.1088/0004-637x/806/2/152 2015

  62. [62]

    M., et al

    Tacchella, S., Lang, P., Carollo, C. M., et al. 2015, ApJ, 802, 101, doi: 10.1088/0004-637X/802/2/101

    work page doi:10.1088/0004-637x/802/2/101 2015

  63. [63]

    2024, Nature, 636, 69, doi: 10.1038/s41586-024-08201-6

    Tan, Q.-H., Daddi, E., Magnelli, B., et al. 2024, Nature, 636, 69, doi: 10.1038/s41586-024-08201-6

    work page doi:10.1038/s41586-024-08201-6 2024

  64. [64]

    2020, Atoms, 8, 4, doi: 10.3390/atoms8010004

    Thorsbro, B. 2020, Atoms, 8, 4, doi: 10.3390/atoms8010004

    work page doi:10.3390/atoms8010004 2020

  65. [65]

    2018, ApJ, 866, 52, doi: 10.3847/1538-4357/aadb97

    Thorsbro, B., Ryde, N., Schultheis, M., et al. 2018, ApJ, 866, 52, doi: 10.3847/1538-4357/aadb97

    work page doi:10.3847/1538-4357/aadb97 2018

  66. [66]

    , keywords =

    Thorsbro, B., Ryde, N., Rich, R. M., et al. 2020, ApJ, 894, 26, doi: 10.3847/1538-4357/ab8226

    work page doi:10.3847/1538-4357/ab8226 2020

  67. [67]

    , keywords =

    Valenti, E., Ferraro, F. R., & Origlia, L. 2010, MNRAS, 402, 1729, doi: 10.1111/j.1365-2966.2009.15991.x Van der Swaelmen, M., Barbuy, B., Hill, V., et al. 2016, A&A, 586, A1, doi: 10.1051/0004-6361/201525709

    work page doi:10.1111/j.1365-2966.2009.15991.x 2010

  68. [68]

    R., et al

    Zullo, G., Pallanca, C., Ferraro, F. R., et al. 2026, A&A, 709, A212, doi: 10.1051/0004-6361/202659349

    work page doi:10.1051/0004-6361/202659349 2026