pith. sign in

arxiv: 2606.25144 · v1 · pith:DLIGABJLnew · submitted 2026-06-23 · 🌌 astro-ph.SR · astro-ph.GA

Ba Isotope Ratio in CEMP-s and CEMP-rs Stars as a Signature of s-Process and i-Process

Tatyana Sitnova , Lyudmila Mashonkina This is my paper

Pith reviewed 2026-06-25 22:26 UTC · model grok-4.3

classification 🌌 astro-ph.SR astro-ph.GA
keywords barium isotopesCEMP starss-processi-processNLTE abundancesmetal-poor starsnucleosynthesiscarbon-enhanced stars
0
0 comments X

The pith

Barium odd-isotope fractions reach 0.65 in one CEMP-rs star but only 0.23 in two CEMP-s stars.

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

The paper measures the fraction of odd barium isotopes through NLTE analysis of Ba II lines in three carbon-enhanced metal-poor stars. The CEMP-rs star shows a markedly higher fraction than the two CEMP-s stars. This difference is presented as evidence that the isotope ratio can serve as an observable signature separating s-process from i-process contributions. The work supplies a public tool for generating Ba II line lists at chosen isotope fractions. It concludes that more NLTE abundances for additional elements are needed to tighten constraints on i-process sites.

Core claim

F_odd equals 0.65 with large uncertainties in the CEMP-rs star SDSS J1349-0229, while the CEMP-s stars BPS CS 29512-073 and SDSS J1036+1212 both give F_odd equal to 0.23; these distinct values are taken to indicate that the odd-isotope fraction traces the relative importance of s-process and i-process nucleosynthesis.

What carries the argument

The odd-isotope fraction F_odd of barium, extracted from NLTE synthetic spectra of Ba II lines.

If this is right

  • Barium isotope ratios can be used to classify the dominant neutron-capture process in individual CEMP stars.
  • NLTE analysis must be extended to many more elements before firm limits can be placed on i-process yields.
  • The provided line-list generator allows observers to test different F_odd values directly against spectra.

Where Pith is reading between the lines

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

  • If the pattern holds, i-process sites must produce a distinctly higher odd-Ba fraction than the main s-process.
  • Binary mass-transfer models for CEMP-rs stars may need to incorporate an i-process component whose efficiency varies with companion mass or metallicity.
  • Repeating the measurement at higher spectral resolution could shrink the error bars and test whether the current values are resolution-limited.

Load-bearing premise

NLTE modeling and the adopted Ba II line data produce isotope fractions that reflect the stars' nucleosynthetic history rather than being dominated by uncertainties in stellar parameters or atomic data.

What would settle it

A larger sample of CEMP-s and CEMP-rs stars in which the two groups show overlapping F_odd distributions would remove the claimed distinction.

Figures

Figures reproduced from arXiv: 2606.25144 by Lyudmila Mashonkina, Tatyana Sitnova.

Figure 1
Figure 1. Figure 1: NLTE abundance difference between the subordinate and the resonance lines of Ba II as a function of Fodd in the sample stars (circles). Shaded area indicates the uncertainty in ∆Ba(sub.-res.). The impact of Fodd on the Ba II 4934 Å line profile might be less prominent compared to its impact on a total absorbed energy. In SDSS J1349-0229 and SDSS J1036+1212, EWs of the Ba II 4934 Å lines amount to 106 mÅ an… view at source ↗
Figure 2
Figure 2. Figure 2: Fodd as a function of [Ba/Eu] in the sample stars: SDSS J1036+1212 (green circle), BPS CS 29512-073 (rosy circle), and SDSS J1349-0229 (orange square). The stars from Sitnova et al. [30] are shown with open symbols. For comparison, we show the theoretical predictions for the r-process (dashed line) and the s-process (dash-dotted line). The s- and r-process material mixture is shown with the dotted line, wh… view at source ↗
read the original abstract

We present a spectroscopic analysis of three carbon-enhanced metal-poor (CEMP) stars of type CEMP-s and CEMP-rs and determine their non-local thermodynamic equilibrium (NLTE) abundances of Ba and the fractions of the odd Ba isotopes (F$_{\rm odd}$). We found F$_{\rm odd}$ = 0.65$_{-0.34}^{+0.35}$ in SDSS J1349-0229, which is known in the literature as a CEMP-rs star, while the other two stars, BPS CS 29512-073 and SDSS J1036+1212, exhibit lower F$_{\rm odd}$ = 0.23$_{-0.10}^{+0.19}$ and 0.23$_{-0.11}^{+0.22}$, respectively, and they are known in the literature as CEMP-s stars. The present result supports our earlier finding about distinct F$_{\rm odd}$ in CEMP-s and CEMP-rs stars. For obtaining observational constraints on i-process nucleosynthesis, further NLTE abundance determinations for many chemical elements are required. We provide a tool for generating the lists of Ba II lines for a given F$_{\rm odd}$ and it is available on GitHub https://github.com/sitamih/ba_linelist.

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

2 major / 1 minor

Summary. The manuscript reports NLTE spectroscopic measurements of barium odd-isotope fractions (F_odd) in three CEMP stars. It finds F_odd = 0.65_{-0.34}^{+0.35} for the CEMP-rs star SDSS J1349-0229 and F_odd = 0.23 with smaller uncertainties (~0.1-0.2) for the two CEMP-s stars BPS CS 29512-073 and SDSS J1036+1212. These values are interpreted as supporting distinct nucleosynthetic origins (i-process vs. s-process), extending prior work by the authors, and a GitHub tool is provided for generating Ba II line lists at given F_odd.

Significance. If the reported distinction in F_odd survives detailed scrutiny of the error budget, the result would supply a direct observational diagnostic separating i-process and s-process contributions in CEMP stars. The open GitHub tool for line-list generation is a clear strength that aids reproducibility and future work.

major comments (2)
  1. [Abstract / results for SDSS J1349-0229] Abstract and results presentation: the central claim of 'distinct F_odd' in CEMP-rs vs. CEMP-s stars is load-bearing, yet the quoted values overlap (CEMP-rs range 0.31-1.00; CEMP-s range ~0.13-0.42). The difference of 0.42 is only ~1.2 sigma given the combined uncertainties; no quantitative statistical test (e.g., significance of the difference or posterior overlap) is described.
  2. [Methods / abundance analysis section] The error budget on F_odd (NLTE modeling, stellar parameters, Ba II atomic data) must be shown to be complete and not dominated by systematics, because the weakest assumption is that these uncertainties accurately reflect nucleosynthetic origin rather than analysis artifacts. Explicit propagation or sensitivity tests are required to support the quoted asymmetric errors.
minor comments (1)
  1. The GitHub link is useful; ensure the repository contains versioned code, example inputs, and a README that reproduces the line lists used in the paper.

Simulated Author's Rebuttal

2 responses · 0 unresolved

We thank the referee for the detailed and constructive report. We address each major comment below and will revise the manuscript to incorporate additional statistical discussion and explicit error analysis.

read point-by-point responses

  1. Referee: [Abstract / results for SDSS J1349-0229] Abstract and results presentation: the central claim of 'distinct F_odd' in CEMP-rs vs. CEMP-s stars is load-bearing, yet the quoted values overlap (CEMP-rs range 0.31-1.00; CEMP-s range ~0.13-0.42). The difference of 0.42 is only ~1.2 sigma given the combined uncertainties; no quantitative statistical test (e.g., significance of the difference or posterior overlap) is described.

    Authors: We agree that the F_odd values overlap within the quoted uncertainties and that the difference between the central values is only approximately 1.2 sigma. The central values remain consistent with theoretical expectations (F_odd ~0.1-0.3 for s-process and higher for i-process), but we acknowledge that a quantitative test of the difference is needed. In the revised manuscript we will add an explicit assessment, such as the posterior overlap probability or a simple two-sample comparison, to quantify the statistical support for distinct origins. revision: yes

  2. Referee: [Methods / abundance analysis section] The error budget on F_odd (NLTE modeling, stellar parameters, Ba II atomic data) must be shown to be complete and not dominated by systematics, because the weakest assumption is that these uncertainties accurately reflect nucleosynthetic origin rather than analysis artifacts. Explicit propagation or sensitivity tests are required to support the quoted asymmetric errors.

    Authors: We agree that the error budget requires explicit demonstration that it is not dominated by unaccounted systematics. The current asymmetric uncertainties were derived from our NLTE fits, but the revised methods section will include dedicated sensitivity tests: we will vary T_eff, log g, microturbulence, and Ba II atomic data within their literature uncertainties, re-derive F_odd for each case, and show the resulting range. This will confirm that the quoted errors capture the dominant contributions and are not artifacts of the analysis. revision: yes

Circularity Check

0 steps flagged

No circularity: direct spectroscopic derivation of F_odd from observed spectra

full rationale

The paper performs NLTE spectroscopic analysis on three CEMP stars to extract Ba abundances and odd-isotope fractions F_odd directly from Ba II line profiles in the observed spectra. No equations or fitting procedures are described that reduce the reported F_odd values (0.65, 0.23, 0.23) to quantities previously fitted or assumed by the same authors. The statement that the results 'support our earlier finding' is contextual commentary on consistency with prior work and does not serve as a load-bearing premise for the new measurements. The provided GitHub tool for generating line lists is a utility, not part of the derivation chain. The analysis is self-contained against external benchmarks (stellar spectra and atomic data), satisfying the criteria for an honest non-finding of circularity.

Axiom & Free-Parameter Ledger

0 free parameters · 1 axioms · 0 invented entities

The central claim rests on the accuracy of NLTE line formation calculations for Ba II in metal-poor atmospheres and on the assumption that the measured F_odd directly traces the nucleosynthesis channel.

axioms (1)
  • domain assumption NLTE effects are correctly modeled for the Ba II lines used to derive F_odd
    The paper determines NLTE abundances and isotope fractions.

pith-pipeline@v0.9.1-grok · 5784 in / 1238 out tokens · 38972 ms · 2026-06-25T22:26:43.240594+00:00 · methodology

discussion (0)

Sign in with ORCID, Apple, or X to comment. Anyone can read and Pith papers without signing in.

Reference graph

Works this paper leans on

71 extracted references · 31 linked inside Pith

  1. [1]

    Synthesis of the Elements in Stars

    Burbidge, E.M.; Burbidge, G.R.; Fowler, W.A.; Hoyle, F. Synthesis of the Elements in Stars. Reviews of Modern Physics1957,29, 547–650. https://doi.org/10.1103/RevModPhys.29.547

    doi:10.1103/revmodphys.29.547

  2. [2]

    Production of 14C and neutrons in red giants.ApJ1977,212, 149–158

    Cowan, J.J.; Rose, W.K. Production of 14C and neutrons in red giants.ApJ1977,212, 149–158. https://doi.org/10.1086/155030

    doi:10.1086/155030

  3. [3]

    Evolution and Nucleosynthesis in Low-Mass Asymptotic Giant Branch Stars

    Gallino, R.; Arlandini, C.; Busso, M.; Lugaro, M.; Travaglio, C.; Straniero, O.; Chieffi, A.; Limongi, M. Evolution and Nucleosynthesis in Low-Mass Asymptotic Giant Branch Stars. II. Neutron Capture and the S-Process.ApJ1998,497, 388–403. https://doi.org/10.1086/305437

    doi:10.1086/305437

  4. [4]

    Evolution of Asymptotic Giant Branch Stars.ARA&A2005,43, 435–479

    Herwig, F. Evolution of Asymptotic Giant Branch Stars.ARA&A2005,43, 435–479. https: //doi.org/10.1146/annurev.astro.43.072103.150600

    doi:10.1146/annurev.astro.43.072103.150600

  5. [5]

    Herwig, F.; Pignatari, M.; Woodward, P .R.; Porter, D.H.; Rockefeller, G.; Fryer, C.L.; Bennett, M.; Hirschi, R. Convective-reactive Proton-12C Combustion in Sakurai’s Object (V4334 Sagittarii) and Implications for the Evolution and Yields from the First Generations of Stars.ApJ2011, 727, 89, [arXiv:astro-ph.SR/1002.2241]. https://doi.org/10.1088/0004-637...

    Pith/arXiv arXiv doi:10.1088/0004-637x/727/2/89

  6. [6]

    Constraints of the Physics of Low-mass AGB Stars from CH and CEMP Stars.ApJ2016,833, 181, [arXiv:astro- ph.SR/1610.05475]

    Cristallo, S.; Karinkuzhi, D.; Goswami, A.; Piersanti, L.; Gobrecht, D. Constraints of the Physics of Low-mass AGB Stars from CH and CEMP Stars.ApJ2016,833, 181, [arXiv:astro- ph.SR/1610.05475]. https://doi.org/10.3847/1538-4357/833/2/181

    Pith/arXiv arXiv doi:10.3847/1538-4357/833/2/181

  7. [7]

    The intermediate neutron capture process

    Choplin, A.; Siess, L.; Goriely, S. The intermediate neutron capture process. III. The i-process in AGB stars of different masses and metallicities without overshoot.A&A2022,667, A155, [arXiv:astro-ph.SR/2209.10303]. https://doi.org/10.1051/0004-6361/202244360

    doi:10.1051/0004-6361/202244360

  8. [8]

    The intermediate neutron capture process

    Choplin, A.; Siess, L.; Goriely, S.; Martinet, S. The intermediate neutron capture process. V . The i-process in AGB stars with overshoot.A&A2024,684, A206, [arXiv:astro-ph.SR/2402.10284]. https://doi.org/10.1051/0004-6361/202348957

    doi:10.1051/0004-6361/202348957

  9. [9]

    Denissenkov, P .A.; Herwig, F.; Woodward, P .; Andrassy, R.; Pignatari, M.; Jones, S. The i- process yields of rapidly accreting white dwarfs from multicycle He-shell flash stellar evolution models with mixing parametrizations from 3D hydrodynamics simulations.MNRAS2019, 488, 4258–4270, [arXiv:astro-ph.SR/1809.03666]. https://doi.org/10.1093/mnras/stz1921

    Pith/arXiv arXiv doi:10.1093/mnras/stz1921

  10. [10]

    Chemical evolution with rotating massive star yields II

    Prantzos, N.; Abia, C.; Cristallo, S.; Limongi, M.; Chieffi, A. Chemical evolution with rotating massive star yields II. A new assessment of the solar s- and r-process components.MNRAS2020, 491, 1832–1850, [arXiv:astro-ph.GA/1911.02545]. https://doi.org/10.1093/mnras/stz3154

    doi:10.1093/mnras/stz3154 1911

  11. [11]

    The Incidence of Binaries among Very Metal-poor Carbon Stars.AJ 2001,122, 1545–1560

    Preston, G.W.; Sneden, C. The Incidence of Binaries among Very Metal-poor Carbon Stars.AJ 2001,122, 1545–1560. https://doi.org/10.1086/322082

    doi:10.1086/322082 2001

  12. [12]

    The Binary Frequency Among Carbon-enhanced, s-Process-rich, Metal-poor Stars.ApJ2005,625, 825–832, [arXiv:astro-ph/astro-ph/0412422]

    Lucatello, S.; Tsangarides, S.; Beers, T.C.; Carretta, E.; Gratton, R.G.; Ryan, S.G. The Binary Frequency Among Carbon-enhanced, s-Process-rich, Metal-poor Stars.ApJ2005,625, 825–832, [arXiv:astro-ph/astro-ph/0412422]. https://doi.org/10.1086/428104

    Pith/arXiv arXiv doi:10.1086/428104

  13. [13]

    Binarity in carbon-enhanced metal-poor stars.MNRAS2014,441, 1217–1229, [arXiv:astro-ph.SR/1404.0385]

    Starkenburg, E.; Shetrone, M.D.; McConnachie, A.W.; Venn, K.A. Binarity in carbon-enhanced metal-poor stars.MNRAS2014,441, 1217–1229, [arXiv:astro-ph.SR/1404.0385]. https://doi. org/10.1093/mnras/stu623. https://doi.org/ Galaxies2026,14, 42 10 of 20

    Pith/arXiv arXiv doi:10.1093/mnras/stu623

  14. [14]

    The Discovery and Analysis of Very Metal-Poor Stars in the Galaxy

    Beers, T.C.; Christlieb, N. The Discovery and Analysis of Very Metal-Poor Stars in the Galaxy. ARA&A2005,43, 531–580. https://doi.org/10.1146/annurev.astro.42.053102.134057

    doi:10.1146/annurev.astro.42.053102.134057

  15. [15]

    The Hamburg/ESO R-process enhanced star survey (HERES)

    Jonsell, K.; Barklem, P .S.; Gustafsson, B.; Christlieb, N.; Hill, V .; Beers, T.C.; Holmberg, J. The Hamburg/ESO R-process enhanced star survey (HERES). III. HE 0338-3945 and the formation of the r + s stars.A&A2006,451, 651–670, [arXiv:astro-ph/astro-ph/0601476]. https://doi.org/ 10.1051/0004-6361:20054470

    Pith/arXiv arXiv doi:10.1051/0004-6361:20054470

  16. [16]

    How plausible are the proposed formation scenarios of CEMP-r/s stars?A&A2016,587, A50, [arXiv:astro-ph.SR/1601.00976]

    Abate, C.; Stancliffe, R.J.; Liu, Z.W. How plausible are the proposed formation scenarios of CEMP-r/s stars?A&A2016,587, A50, [arXiv:astro-ph.SR/1601.00976]. https://doi.org/10.105 1/0004-6361/201527864

    Pith/arXiv arXiv

  17. [17]

    Abundances and kinematics of carbon-enhanced metal-poor stars in the Galactic halo

    Hansen, C.J.; Hansen, T.T.; Koch, A.; Beers, T.C.; Nordström, B.; Placco, V .M.; Andersen, J. Abundances and kinematics of carbon-enhanced metal-poor stars in the Galactic halo. A new classification scheme based on Sr and Ba.A&A2019,623, A128, [arXiv:astro-ph.SR/1901.05968]. https://doi.org/10.1051/0004-6361/201834601

    Pith/arXiv arXiv doi:10.1051/0004-6361/201834601 1901

  18. [18]

    Low-mass low-metallicity AGB stars as an efficient i-process site explaining CEMP-rs stars.A&A 2021,645, A61, [arXiv:astro-ph.SR/2010.13620]

    Karinkuzhi, D.; Van Eck, S.; Goriely, S.; Siess, L.; Jorissen, A.; Merle, T.; Escorza, A.; Masseron, T. Low-mass low-metallicity AGB stars as an efficient i-process site explaining CEMP-rs stars.A&A 2021,645, A61, [arXiv:astro-ph.SR/2010.13620]. https://doi.org/10.1051/0004-6361/202038891

    doi:10.1051/0004-6361/202038891 2021

  19. [19]

    Spectroscopic study of CEMP-(s & r/s) stars

    Goswami, P .P .; Rathour, R.S.; Goswami, A. Spectroscopic study of CEMP-(s & r/s) stars. Revisiting classification criteria and formation scenarios, highlighting i-process nucleosynthesis. A&A2021,649, A49, [arXiv:astro-ph.SR/2101.09518]. https://doi.org/10.1051/0004-6361/2020 38258

    doi:10.1051/0004-6361/2020 2020

  20. [20]

    The chemical composition of HD 196944: a carbon and s-process rich, very metal-poor star.A&A1998,337, 216–222

    Zacs, L.; Nissen, P .E.; Schuster, W.J. The chemical composition of HD 196944: a carbon and s-process rich, very metal-poor star.A&A1998,337, 216–222

  21. [21]

    Discovery of three lead-rich stars.Nature2001, 412, 793–795

    Van Eck, S.; Goriely, S.; Jorissen, A.; Plez, B. Discovery of three lead-rich stars.Nature2001, 412, 793–795. https://doi.org/10.1038/35090514

    doi:10.1038/35090514

  22. [22]

    A Subaru/High Dispersion Spectrograph Study of Lead (Pb) Abundances in Eight s-Process Element-rich, Metal- poor Stars.ApJ2002,580, 1149–1158, [arXiv:astro-ph/astro-ph/0208020]

    Aoki, W.; Ryan, S.G.; Norris, J.E.; Beers, T.C.; Ando, H.; Tsangarides, S. A Subaru/High Dispersion Spectrograph Study of Lead (Pb) Abundances in Eight s-Process Element-rich, Metal- poor Stars.ApJ2002,580, 1149–1158, [arXiv:astro-ph/astro-ph/0208020]. https://doi.org/10.1 086/343885

    Pith/arXiv arXiv

  23. [23]

    Chemical abundances in 43 metal-poor stars.A&A2005,440, 321–343, [arXiv:astro-ph/astro-ph/0505118]

    Jonsell, K.; Edvardsson, B.; Gustafsson, B.; Magain, P .; Nissen, P .E.; Asplund, M. Chemical abundances in 43 metal-poor stars.A&A2005,440, 321–343, [arXiv:astro-ph/astro-ph/0505118]. https://doi.org/10.1051/0004-6361:20052797

    Pith/arXiv arXiv doi:10.1051/0004-6361:20052797

  24. [24]

    A holistic approach to carbon-enhanced metal-poor stars.A&A2010,509, A93, [arXiv:astro- ph.SR/0901.4737]

    Masseron, T.; Johnson, J.A.; Plez, B.; van Eck, S.; Primas, F.; Goriely, S.; Jorissen, A. A holistic approach to carbon-enhanced metal-poor stars.A&A2010,509, A93, [arXiv:astro- ph.SR/0901.4737]. https://doi.org/10.1051/0004-6361/200911744

    Pith/arXiv arXiv doi:10.1051/0004-6361/200911744

  25. [25]

    A Search for Stars of Very Low Metal Abundance

    Roederer, I.U.; Preston, G.W.; Thompson, I.B.; Shectman, S.A.; Sneden, C.; Burley, G.S.; Kelson, D.D. A Search for Stars of Very Low Metal Abundance. VI. Detailed Abundances of 313 Metal- poor Stars.AJ2014,147, 136, [arXiv:astro-ph.SR/1403.6853]. https://doi.org/10.1088/0004-625 6/147/6/136

    Pith/arXiv arXiv doi:10.1088/0004-625

  26. [26]

    Hubble Space Telescope Near-Ultraviolet Spectroscopy of Bright CEMP-s Stars.ApJ2015,812, 109, [arXiv:astro-ph.SR/1508.05872]

    Placco, V .M.; Beers, T.C.; Ivans, I.I.; Filler, D.; Imig, J.A.; Roederer, I.U.; Abate, C.; Hansen, T.; Cowan, J.J.; Frebel, A.; et al. Hubble Space Telescope Near-Ultraviolet Spectroscopy of Bright CEMP-s Stars.ApJ2015,812, 109, [arXiv:astro-ph.SR/1508.05872]. https://doi.org/10.1088/00 04-637X/812/2/109

    Pith/arXiv arXiv doi:10.1088/00

  27. [27]

    New Stellar Parameters, Metallicities, and Elemental Abundance Ratios for 311 Metal-poor Stars.AJ2025,169, 172, [arXiv:astro-ph.SR/2502.15915]

    Mittal, S.; Roederer, I.U. New Stellar Parameters, Metallicities, and Elemental Abundance Ratios for 311 Metal-poor Stars.AJ2025,169, 172, [arXiv:astro-ph.SR/2502.15915]. https: //doi.org/10.3847/1538-3881/adadf0

    doi:10.3847/1538-3881/adadf0

  28. [28]

    Roederer, I.U.; Placco, V .M.; Karakas, A.I.; Den Hartog, E.A.; Beers, T.C. Abundances of Rarely Detected s-process Elements Derived from the Ultraviolet Spectrum of the s-process- enhanced Metal-poor Star HD 196944.ApJ2025,995, 2, [arXiv:astro-ph.SR/2510.11922]. https: //doi.org/10.3847/1538-4357/ae12e7

    doi:10.3847/1538-4357/ae12e7

  29. [29]

    Carbon-enhanced metal-poor stars: a window on AGB nucleosynthesis and binary evolution

    Abate, C.; Pols, O.R.; Izzard, R.G.; Karakas, A.I. Carbon-enhanced metal-poor stars: a window on AGB nucleosynthesis and binary evolution. II. Statistical analysis of a sample of 67 CEMP-s stars.A&A2015,581, A22, [arXiv:astro-ph.SR/1507.04662]. https://doi.org/10.1051/0004-636 1/201525876. https://doi.org/ Galaxies2026,14, 42 11 of 20

    Pith/arXiv arXiv doi:10.1051/0004-636

  30. [30]

    Distinct barium isotope ratios in CEMP-s and CEMP-rs stars.A&A2025,704, A103, [arXiv:astro- ph.SR/2510.16275]

    Sitnova, T.M.; Mashonkina, L.I.; Romanovskaya, A.M.; Giribaldi, R.E.; Choplin, A. Distinct barium isotope ratios in CEMP-s and CEMP-rs stars.A&A2025,704, A103, [arXiv:astro- ph.SR/2510.16275]. https://doi.org/10.1051/0004-6361/202557031

    doi:10.1051/0004-6361/202557031

  31. [31]

    From the s-Process to the i-Process: A New Perspective on the Chemical Enrichment of Extrinsic Stars.Galaxies2024,12, 89

    Van Eck, S.; Giribaldi, R.; Merle, T.; Lambotte, A.; Karinkuzhi, D.; Goriely, S.; Choplin, A.; Storm, N.; Gerber, J.; Siess, L.; et al. From the s-Process to the i-Process: A New Perspective on the Chemical Enrichment of Extrinsic Stars.Galaxies2024,12, 89. https://doi.org/10.3390/ galaxies12060089

  32. [32]

    Synthesis of actinides and short-lived radionu- clides during i-process nucleosynthesis in AGB stars.European Physical Journal A2025,61, 68, [arXiv:astro-ph.SR/2504.08058]

    Choplin, A.; Goriely, S.; Siess, L.; Martinet, S. Synthesis of actinides and short-lived radionu- clides during i-process nucleosynthesis in AGB stars.European Physical Journal A2025,61, 68, [arXiv:astro-ph.SR/2504.08058]. https://doi.org/10.1140/epja/s10050-025-01522-8

    doi:10.1140/epja/s10050-025-01522-8

  33. [33]

    Three carbon-enhanced metal-poor dwarf stars from the SDSS

    Behara, N.T.; Bonifacio, P .; Ludwig, H.G.; Sbordone, L.; González Hernández, J.I.; Caffau, E. Three carbon-enhanced metal-poor dwarf stars from the SDSS. Chemical abundances from CO5BOLD 3D hydrodynamical model atmospheres.A&A2010,513, A72, [arXiv:astro- ph.SR/1002.1670]. https://doi.org/10.1051/0004-6361/200913213

    Pith/arXiv arXiv doi:10.1051/0004-6361/200913213

  34. [34]

    Elemental abundances and classification of carbon-enhanced metal-poor stars.A&A2012,548, A34, [arXiv:astro- ph.SR/1210.5009]

    Allen, D.M.; Ryan, S.G.; Rossi, S.; Beers, T.C.; Tsangarides, S.A. Elemental abundances and classification of carbon-enhanced metal-poor stars.A&A2012,548, A34, [arXiv:astro- ph.SR/1210.5009]. https://doi.org/10.1051/0004-6361/201015615

    Pith/arXiv arXiv doi:10.1051/0004-6361/201015615

  35. [35]

    Abundance of Heavy r-process Elements in CEMP-rs Stars: The Role of the i-process.ApJ2026,997, 44, [arXiv:astro-ph.SR/2510.13339]

    Riyas, A.M.; Karinkuzhi, D.; Van Eck, S.; Choplin, A.; Goriely, S.; Siess, L.; Keerthy, M.V .; Jorissen, A.; Merle, T. Abundance of Heavy r-process Elements in CEMP-rs Stars: The Role of the i-process.ApJ2026,997, 44, [arXiv:astro-ph.SR/2510.13339]. https://doi.org/10.3847/1538 -4357/ae12a0

    doi:10.3847/1538

  36. [36]

    Exploiting the Gaia EDR3 photometry to derive stellar temperatures.A&A2021,653, A90, [arXiv:astro-ph.SR/2106.03882]

    Mucciarelli, A.; Bellazzini, M.; Massari, D. Exploiting the Gaia EDR3 photometry to derive stellar temperatures.A&A2021,653, A90, [arXiv:astro-ph.SR/2106.03882]. https://doi.org/10 .1051/0004-6361/202140979

    arXiv

  37. [37]

    A 3D Dust Map Based on Gaia, Pan-STARRS 1, and 2MASS.ApJ2019,887, 93, [arXiv:astro-ph.GA/1905.02734]

    Green, G.M.; Schlafly, E.; Zucker, C.; Speagle, J.S.; Finkbeiner, D. A 3D Dust Map Based on Gaia, Pan-STARRS 1, and 2MASS.ApJ2019,887, 93, [arXiv:astro-ph.GA/1905.02734]. https://doi.org/10.3847/1538-4357/ab5362

    Pith/arXiv arXiv doi:10.3847/1538-4357/ab5362 1905

  38. [38]

    On the use of Gaia magnitudes and new tables of bolometric corrections.MNRAS2018,479, L102–L107, [arXiv:astro-ph.SR/1806.01953]

    Casagrande, L.; VandenBerg, D.A. On the use of Gaia magnitudes and new tables of bolometric corrections.MNRAS2018,479, L102–L107, [arXiv:astro-ph.SR/1806.01953]. https://doi.org/10 .1093/mnrasl/sly104

    Pith/arXiv arXiv

  39. [39]

    Gaia Early Data Release 3

    Lindegren, L.; Bastian, U.; Biermann, M.; Bombrun, A.; de Torres, A.; Gerlach, E.; Geyer, R.; Hernández, J.; Hilger, T.; Hobbs, D.; et al. Gaia Early Data Release 3. Parallax bias versus magnitude, colour, and position.A&A2021,649, A4, [arXiv:astro-ph.IM/2012.01742]. https://doi.org/10.1051/0004-6361/202039653

    doi:10.1051/0004-6361/202039653 2012

  40. [40]

    Estimating Distances from Parallaxes.P ASP2015,127, 994, [arXiv:astro- ph.IM/1507.02105]

    Bailer-Jones, C.A.L. Estimating Distances from Parallaxes.P ASP2015,127, 994, [arXiv:astro- ph.IM/1507.02105]. https://doi.org/10.1086/683116

    Pith/arXiv arXiv doi:10.1086/683116

  41. [41]

    A non-LTE study of neutral and singly-ionized iron line spectra in 1D models of the Sun and selected late-type stars.A&A2011, 528, A87, [arXiv:astro-ph.SR/1101.4570]

    Mashonkina, L.; Gehren, T.; Shi, J.R.; Korn, A.J.; Grupp, F. A non-LTE study of neutral and singly-ionized iron line spectra in 1D models of the Sun and selected late-type stars.A&A2011, 528, A87, [arXiv:astro-ph.SR/1101.4570]. https://doi.org/10.1051/0004-6361/201015336

    Pith/arXiv arXiv doi:10.1051/0004-6361/201015336

  42. [42]

    1D non-LTE corrections for chemical abundance analyses of very metal-poor stars.MNRAS2023, 524, 3526–3536, [arXiv:astro-ph.SR/2307.04523]

    Mashonkina, L.; Pakhomov, Y.; Sitnova, T.; Smogorzhevskii, A.; Jablonka, P .; Hill, V . 1D non-LTE corrections for chemical abundance analyses of very metal-poor stars.MNRAS2023, 524, 3526–3536, [arXiv:astro-ph.SR/2307.04523]. https://doi.org/10.1093/mnras/stad2114

    doi:10.1093/mnras/stad2114

  43. [43]

    Mashonkina, L.; Sitnova, T.; Yakovleva, S.A.; Belyaev, A.K. Influence of inelastic collisions with hydrogen atoms on the non-local thermodynamic equilibrium line formation for Fe I and Fe II in the 1D model atmospheres of late-type stars.A&A2019,631, A43, [arXiv:astro- ph.SR/1908.02478]. https://doi.org/10.1051/0004-6361/201935753

    doi:10.1051/0004-6361/201935753 1908

  44. [44]

    Systematic Non-LTE Study of the -2.6 < [Fe/H] < 0.2 F and G dwarfs in the Solar Neighborhood

    Sitnova, T.; Zhao, G.; Mashonkina, L.; Chen, Y.; Liu, F.; Pakhomov, Y.; Tan, K.; Bolte, M.; Alexeeva, S.; Grupp, F.; et al. Systematic Non-LTE Study of the -2.6 < [Fe/H] < 0.2 F and G dwarfs in the Solar Neighborhood. I. Stellar Atmosphere Parameters.ApJ2015,808, 148, [arXiv:astro-ph.SR/1506.01621]. https://doi.org/10.1088/0004-637X/808/2/148

    Pith/arXiv arXiv doi:10.1088/0004-637x/808/2/148

  45. [45]

    An absolutely calibrated Te f f scale from the infrared flux method

    Casagrande, L.; Ramírez, I.; Meléndez, J.; Bessell, M.; Asplund, M. An absolutely calibrated Te f f scale from the infrared flux method. Dwarfs and subgiants.A&A2010,512, A54, [arXiv:astro- ph.SR/1001.3142]. https://doi.org/10.1051/0004-6361/200913204. https://doi.org/ Galaxies2026,14, 42 12 of 20

    Pith/arXiv arXiv doi:10.1051/0004-6361/200913204

  46. [46]

    Deriving Stellar Effective Temperatures of Metal-poor Stars with the Excitation Potential Method.ApJ2013,769, 57, [arXiv:astro- ph.GA/1304.2396]

    Frebel, A.; Casey, A.R.; Jacobson, H.R.; Yu, Q. Deriving Stellar Effective Temperatures of Metal-poor Stars with the Excitation Potential Method.ApJ2013,769, 57, [arXiv:astro- ph.GA/1304.2396]. https://doi.org/10.1088/0004-637X/769/1/57

    Pith/arXiv arXiv doi:10.1088/0004-637x/769/1/57

  47. [47]

    VALD: The Vienna Atomic Line Data Base.A&AS1995,112, 525

    Piskunov, N.E.; Kupka, F.; Ryabchikova, T.A.; Weiss, W.W.; Jeffery, C.S. VALD: The Vienna Atomic Line Data Base.A&AS1995,112, 525

  48. [48]

    Hyperfine Splitting in the VALD Database of Spectral-line Parameters.Astronomy Reports2019,63, 1010–1021, [arXiv:astro-ph.IM/1911.03189]

    Pakhomov, Y.V .; Ryabchikova, T.A.; Piskunov, N.E. Hyperfine Splitting in the VALD Database of Spectral-line Parameters.Astronomy Reports2019,63, 1010–1021, [arXiv:astro-ph.IM/1911.03189]. https://doi.org/10.1134/S1063772919120047

    doi:10.1134/s1063772919120047 1911

  49. [49]

    Critical Evaluation of Transition Probabilities for Ba I and Ba II.Atomic Data1969,1, 1–+

    Miles, B.M.; Wiese, W.L. Critical Evaluation of Transition Probabilities for Ba I and Ba II.Atomic Data1969,1, 1–+. (MW), https://doi.org/10.1016/S0092-640X(69)80019-7

    doi:10.1016/s0092-640x(69)80019-7

  50. [50]

    Precision measurement of branching fractions of 138Ba+ : Testing many-body theories below the 1% level.Phys

    De Munshi, D.; Dutta, T.; Rebhi, R.; Mukherjee, M. Precision measurement of branching fractions of 138Ba+ : Testing many-body theories below the 1% level.Phys. Rev. A2015,91, 040501, [arXiv:physics.atom-ph/1411.5041]. https://doi.org/10.1103/PhysRevA.91.040501

    Pith/arXiv arXiv doi:10.1103/physreva.91.040501

  51. [51]

    An exacting transition probability measurement - a direct test of atomic many-body theories.Scientific Reports2016,6, 29772, [arXiv:physics.atom-ph/1604.01488]

    Dutta, T.; de Munshi, D.; Yum, D.; Rebhi, R.; Mukherjee, M. An exacting transition probability measurement - a direct test of atomic many-body theories.Scientific Reports2016,6, 29772, [arXiv:physics.atom-ph/1604.01488]. https://doi.org/10.1038/srep29772

    Pith/arXiv arXiv doi:10.1038/srep29772

  52. [52]

    Improved Laboratory Transition Parameters forEu II and Application to the Solar Europium Elemental and Isotopic Composition

    Lawler, J.E.; Wickliffe, M.E.; den Hartog, E.A.; Sneden, C. Improved Laboratory Transition Parameters forEu II and Application to the Solar Europium Elemental and Isotopic Composition. Astrophys. J.2001,563, 1075–1088. (LWHS), https://doi.org/10.1086/323407

    doi:10.1086/323407 2001

  53. [53]

    Relativistic J-dependence of the isotope shift in the 6s-6p doublet of Ba II.Zeitschrift fur Physik A Hadrons and Nuclei1984,318, 125–129

    Wendt, K.; Ahmad, S.A.; Buchinger, F.; Mueller, A.C.; Neugart, R.; Otten, E.W. Relativistic J-dependence of the isotope shift in the 6s-6p doublet of Ba II.Zeitschrift fur Physik A Hadrons and Nuclei1984,318, 125–129. https://doi.org/10.1007/BF01413460

    doi:10.1007/bf01413460

  54. [54]

    Hühnermann, H.; Möller, W.; Alkhazov, G.; Panteleev, V . .Inst. Phys. Conf. Ser.1992, 132, 209–211

    1992

  55. [55]

    How accurate are the “muonic” quadrupole moments in Eu?Physical Review Letters1993,70, 541–543

    Möller, W.; Hühnermann, H.; Alkhazov, G.; Panteleev, V . How accurate are the “muonic” quadrupole moments in Eu?Physical Review Letters1993,70, 541–543. https://doi.org/10.1103/ PhysRevLett.70.541

  56. [56]

    Mea- surements of Hyperfine Structure of Stable and Instable Eu+ in a Paul Trap.Laser physics1998, 8, 657–663

    Revalde, G.; Enders, K.; Stachowska, E.; Marx, G.; Zolch, C.; Dembcynski, J.; Werth, G. Mea- surements of Hyperfine Structure of Stable and Instable Eu+ in a Paul Trap.Laser physics1998, 8, 657–663

  57. [57]

    Software for NLTE Spectrum Fitting

    Tsymbal, V .; Ryabchikova, T.; Sitnova, T. Software for NLTE Spectrum Fitting. In Proceedings of the Physics of Magnetic Stars; Kudryavtsev, D.O.; Romanyuk, I.I.; Yakunin, I.A., Eds., 2019, Vol. 518,Astronomical Society of the Pacific Conference Series, pp. 247–252

    2019

  58. [58]

    BinMag: Widget for comparing stellar observed with theoretical spectra, 2018, [1805.015]

    Kochukhov, O. BinMag: Widget for comparing stellar observed with theoretical spectra, 2018, [1805.015]

    2018

  59. [59]

    9, University of London, [arXiv:0805.0554]

    Butler, K.; Giddings, J.Newsletter on the analysis of astronomical spectra1985,No. 9, University of London, [arXiv:0805.0554]

    Pith/arXiv arXiv

  60. [60]

    Even-to-Odd Barium Isotope Ratio in Selected Galactic Halo Stars.Astronomy Letters2019,45, 341–352, [arXiv:astro-ph.SR/1906.10600]

    Mashonkina, L.I.; Belyaev, A.K. Even-to-Odd Barium Isotope Ratio in Selected Galactic Halo Stars.Astronomy Letters2019,45, 341–352, [arXiv:astro-ph.SR/1906.10600]. https://doi.org/10 .1134/S1063773719060033

    arXiv 1906

  61. [61]

    Barium and europium abundances in cool dwarf stars and nucle- osynthesis of heavy elements.A&A2000,364, 249–264

    Mashonkina, L.; Gehren, T. Barium and europium abundances in cool dwarf stars and nucle- osynthesis of heavy elements.A&A2000,364, 249–264

  62. [62]

    3D NLTE modelling of Y and Eu

    Storm, N.; Barklem, P .S.; Yakovleva, S.A.; Belyaev, A.K.; Palmeri, P .; Quinet, P .; Lodders, K.; Bergemann, M.; Hoppe, R. 3D NLTE modelling of Y and Eu. Centre-to-limb variation and solar abundances.A&A2024,683, A200, [arXiv:astro-ph.SR/2401.13450]. https://doi.org/10.1051/ 0004-6361/202348971

    arXiv

  63. [63]

    A grid of MARCS model atmospheres for late-type stars

    Gustafsson, B.; Edvardsson, B.; Eriksson, K.; Jørgensen, U.G.; Nordlund, Å.; Plez, B. A grid of MARCS model atmospheres for late-type stars. I. Methods and general properties.A&A2008, 486, 951–970, [0805.0554]. https://doi.org/10.1051/0004-6361:200809724

    Pith/arXiv arXiv doi:10.1051/0004-6361:200809724

  64. [64]

    Hyperfine Structure in the Barium Resonance Line: Curves of Growth for Solar and r-Process Isotopic Mixtures.ApJ1989,346, 1030

    Cowley, C.R.; Frey, M. Hyperfine Structure in the Barium Resonance Line: Curves of Growth for Solar and r-Process Isotopic Mixtures.ApJ1989,346, 1030. https://doi.org/10.1086/168085

    doi:10.1086/168085

  65. [65]

    Barium abundances in cool dwarf stars as a constraint to s- and r-process nucleosynthesis.A&A1999,343, 519–530

    Mashonkina, L.; Gehren, T.; Bikmaev, I. Barium abundances in cool dwarf stars as a constraint to s- and r-process nucleosynthesis.A&A1999,343, 519–530. https://doi.org/ Galaxies2026,14, 42 13 of 20

  66. [66]

    Barium even-to-odd isotope abundance ratios in thick disk and thin disk stars.A&A2006,456, 313–321, [arXiv:astro-ph/astro-ph/0604198]

    Mashonkina, L.; Zhao, G. Barium even-to-odd isotope abundance ratios in thick disk and thin disk stars.A&A2006,456, 313–321, [arXiv:astro-ph/astro-ph/0604198]. https://doi.org/10.105 1/0004-6361:20054749

    Pith/arXiv arXiv

  67. [67]

    Non-LTE line formation for heavy elements in four very metal-poor stars.A&A2008,478, 529–541, [arXiv:astro-ph/0711.4454]

    Mashonkina, L.; Zhao, G.; Gehren, T.; Aoki, W.; Bergemann, M.; Noguchi, K.; Shi, J.R.; Takada- Hidai, M.; Zhang, H.W. Non-LTE line formation for heavy elements in four very metal-poor stars.A&A2008,478, 529–541, [arXiv:astro-ph/0711.4454]. https://doi.org/10.1051/0004-6361: 20078060

    Pith/arXiv arXiv doi:10.1051/0004-6361:

  68. [68]

    Unlocking the mystery of strontium synthesis in the early Galaxy through analysis of barium isotopes in very metal-poor stars.A&A2025, 699, A262, [arXiv:astro-ph.SR/2506.10193]

    Sitnova, T.M.; Lombardo, L.; Mashonkina, L.I.; Rizzuti, F.; Cescutti, G.; Hansen, C.J.; Bonifacio, P .; Caffau, E.; Koch-Hansen, A.; Meynet, G.; et al. Unlocking the mystery of strontium synthesis in the early Galaxy through analysis of barium isotopes in very metal-poor stars.A&A2025, 699, A262, [arXiv:astro-ph.SR/2506.10193]. https://doi.org/10.1051/000...

    doi:10.1051/0004-6361/202555073

  69. [69]

    The early days of the Sculptor dwarf spheroidal galaxy.A&A 2015,583, A67, [arXiv:astro-ph.GA/1506.08636]

    Jablonka, P .; North, P .; Mashonkina, L.; Hill, V .; Revaz, Y.; Shetrone, M.; Starkenburg, E.; Irwin, M.; Tolstoy, E.; Battaglia, G.; et al. The early days of the Sculptor dwarf spheroidal galaxy.A&A 2015,583, A67, [arXiv:astro-ph.GA/1506.08636]. https://doi.org/10.1051/0004-6361/20152566 1

    Pith/arXiv arXiv doi:10.1051/0004-6361/20152566 2015

  70. [70]

    Lodders, K. Relative Atomic Solar System Abundances, Mass Fractions, and Atomic Masses of the Elements and Their Isotopes, Composition of the Solar Photosphere, and Compositions of the Major Chondritic Meteorite Groups.Space Sci. Rev.2021,217, 44. https://doi.org/10.1007/ s11214-021-00825-8

    2021

  71. [71]

    The s-process in Asymptotic Giant Branch Stars of Low Metallicity and the Composition of Carbon-enhanced Metal-poor Stars.ApJ2012, 747, 2, [arXiv:astro-ph.SR/1112.2757]

    Lugaro, M.; Karakas, A.I.; Stancliffe, R.J.; Rijs, C. The s-process in Asymptotic Giant Branch Stars of Low Metallicity and the Composition of Carbon-enhanced Metal-poor Stars.ApJ2012, 747, 2, [arXiv:astro-ph.SR/1112.2757]. https://doi.org/10.1088/0004-637X/747/1/2. Appendix A Appendix A.1 Figure A1.The H α line profiles in the observed spectra (circles) ...

    Pith/arXiv arXiv doi:10.1088/0004-637x/747/1/2