{"paper":{"title":"Chemo-dynamical reconstruction of Milky Way globular cluster progenitors: Age-metallicity relations and the universality of multiple stellar populations","license":"http://creativecommons.org/licenses/by/4.0/","headline":"Helium enrichment in Milky Way globular clusters depends only on cluster mass and shows no dependence on progenitor origin","cross_cats":["astro-ph.SR"],"primary_cat":"astro-ph.GA","authors_text":"Carmela Lardo, David Valcin, Raul Jimenez","submitted_at":"2026-03-12T11:21:07Z","abstract_excerpt":"Globular clusters encode the hierarchical assembly history of the Milky Way and the physics of multiple stellar populations. Using homogeneous stellar parameters for 69 Galactic globular clusters derived while modelling multiple populations, we reconstruct progenitor-specific age--metallicity relations (AMRs) and test whether helium-related multiple-population (MP) properties depend on progenitor origin once cluster mass and metallicity are controlled for.\n  Ages, helium spreads ($\\delta Y$), mean helium abundances ($\\bar{Y}$), and first-population fractions ($f_{\\rm P1}$) are drawn from hiera"},"claims":{"count":4,"items":[{"kind":"strongest_claim","text":"Neither δY nor Ȳ depends on progenitor origin; the mass–MP scaling is indistinguishable across in-situ and accreted systems. Sequoia clusters alone show higher f_P1 at fixed mass and metallicity.","source":"verdict.strongest_claim","status":"machine_extracted","claim_id":"C1","attestation":"unclaimed"},{"kind":"weakest_assumption","text":"The chemo-dynamical clustering correctly assigns clusters to their true progenitor galaxies and the hierarchical Bayesian CMD modelling accurately recovers ages, helium spreads, mean helium, and first-population fractions without large systematic biases from the data or model choices.","source":"verdict.weakest_assumption","status":"machine_extracted","claim_id":"C2","attestation":"unclaimed"},{"kind":"one_line_summary","text":"Globular cluster progenitors show similar helium enrichment patterns regulated by cluster mass regardless of origin, with chemical enrichment timescales under 2 Gyr and a residual higher first-population fraction only in Sequoia clusters.","source":"verdict.one_line_summary","status":"machine_extracted","claim_id":"C3","attestation":"unclaimed"},{"kind":"headline","text":"Helium enrichment in Milky Way globular clusters depends only on cluster mass and shows no dependence on progenitor origin","source":"verdict.pith_extraction.headline","status":"machine_extracted","claim_id":"C4","attestation":"unclaimed"}],"snapshot_sha256":"e9ea7e398fb1d54b4e9cc3fe9a4c6a97dc90fdb862d2c18202ffa95cc0c7f487"},"source":{"id":"2603.11814","kind":"arxiv","version":2},"verdict":{"id":"a46aa6df-d4ba-43d0-bdc4-98701c0e2aba","model_set":{"reader":"grok-4.3"},"created_at":"2026-05-15T12:28:52.480134Z","strongest_claim":"Neither δY nor Ȳ depends on progenitor origin; the mass–MP scaling is indistinguishable across in-situ and accreted systems. Sequoia clusters alone show higher f_P1 at fixed mass and metallicity.","one_line_summary":"Globular cluster progenitors show similar helium enrichment patterns regulated by cluster mass regardless of origin, with chemical enrichment timescales under 2 Gyr and a residual higher first-population fraction only in Sequoia clusters.","pipeline_version":"pith-pipeline@v0.9.0","weakest_assumption":"The chemo-dynamical clustering correctly assigns clusters to their true progenitor galaxies and the hierarchical Bayesian CMD modelling accurately recovers ages, helium spreads, mean helium, and first-population fractions without large systematic biases from the data or model choices.","pith_extraction_headline":"Helium enrichment in Milky Way globular clusters depends only on cluster mass and shows no dependence on progenitor origin"},"integrity":{"clean":true,"summary":{"advisory":0,"critical":0,"by_detector":{},"informational":0},"endpoint":"/pith/2603.11814/integrity.json","findings":[],"available":true,"detectors_run":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938"},"references":{"count":0,"sample":[],"resolved_work":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57","internal_anchors":0},"formal_canon":{"evidence_count":2,"snapshot_sha256":"9391c18103bf7203239a346037dcddc09c4ebff81586650d523dd65e59ae8476"},"author_claims":{"count":0,"strong_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"builder_version":"pith-number-builder-2026-05-17-v1"}