{"paper":{"title":"The apparent Large Magellanic Cloud star cluster age gap","license":"http://creativecommons.org/licenses/by/4.0/","headline":"The apparent age gap in Large Magellanic Cloud star clusters stems from lower past star formation rates and detection limits on faded objects.","cross_cats":[],"primary_cat":"astro-ph.GA","authors_text":"Andr\\'es E. Piatti, Jonathan H. Klos","submitted_at":"2026-04-21T21:02:53Z","abstract_excerpt":"In the Large Magellanic Cloud (LMC), there have been very few clusters observed with ages between 4 and 11 Gyr. This phenomenon is sometimes referred to as the `LMC age gap'. We constructed a model of the cluster age distribution aimed at reproducing this scenario. We linked the star formation history to the cluster initial mass function via a power-law relation between maximum initial cluster mass and global star formation rate. Using a constant cluster-forming efficiency of 5%, we obtained the cluster formation history. Applying a model of cluster mass loss calibrated using N-body simulation"},"claims":{"count":4,"items":[{"kind":"strongest_claim","text":"In our model, the age gap is a consequence of the star-forming history and current observational limits. The age gap corresponds to a period characterised by a lower star formation rate, whereby no clusters with an initial mass above approximately 2 to 5·10^5 M_⊙ were formed.","source":"verdict.strongest_claim","status":"machine_extracted","claim_id":"C1","attestation":"unclaimed"},{"kind":"weakest_assumption","text":"The power-law relation between maximum initial cluster mass and global star formation rate, combined with a constant 5% cluster-forming efficiency and the need for a linear change in maximum mass between 8 and 12 Gyr; if these relations do not hold, the model would not reproduce the observed gap and old cluster population.","source":"verdict.weakest_assumption","status":"machine_extracted","claim_id":"C2","attestation":"unclaimed"},{"kind":"one_line_summary","text":"A model where maximum cluster mass scales with star formation rate explains the LMC age gap as resulting from low-SFR periods producing only faint clusters that are now hard to detect.","source":"verdict.one_line_summary","status":"machine_extracted","claim_id":"C3","attestation":"unclaimed"},{"kind":"headline","text":"The apparent age gap in Large Magellanic Cloud star clusters stems from lower past star formation rates and detection limits on faded objects.","source":"verdict.pith_extraction.headline","status":"machine_extracted","claim_id":"C4","attestation":"unclaimed"}],"snapshot_sha256":"dce0a5a5d7e09fd45bded7bb039f08e78630f5b594a74f37086a07fb2bf10ee1"},"source":{"id":"2604.19992","kind":"arxiv","version":2},"verdict":{"id":"e22c2510-df31-4385-b036-4bcbcbe8f09e","model_set":{"reader":"grok-4.3"},"created_at":"2026-05-12T01:14:33.889658Z","strongest_claim":"In our model, the age gap is a consequence of the star-forming history and current observational limits. The age gap corresponds to a period characterised by a lower star formation rate, whereby no clusters with an initial mass above approximately 2 to 5·10^5 M_⊙ were formed.","one_line_summary":"A model where maximum cluster mass scales with star formation rate explains the LMC age gap as resulting from low-SFR periods producing only faint clusters that are now hard to detect.","pipeline_version":"pith-pipeline@v0.9.0","weakest_assumption":"The power-law relation between maximum initial cluster mass and global star formation rate, combined with a constant 5% cluster-forming efficiency and the need for a linear change in maximum mass between 8 and 12 Gyr; if these relations do not hold, the model would not reproduce the observed gap and old cluster population.","pith_extraction_headline":"The apparent age gap in Large Magellanic Cloud star clusters stems from lower past star formation rates and detection limits on faded objects."},"integrity":{"clean":true,"summary":{"advisory":0,"critical":0,"by_detector":{},"informational":0},"endpoint":"/pith/2604.19992/integrity.json","findings":[],"available":true,"detectors_run":[{"name":"ai_meta_artifact","ran_at":"2026-05-21T15:39:04.873422Z","status":"completed","version":"1.0.0","findings_count":0},{"name":"doi_compliance","ran_at":"2026-05-20T02:27:57.280264Z","status":"completed","version":"1.0.0","findings_count":0}],"snapshot_sha256":"63097c2046caa04d1d4bef204430aa685f9248152aa224f14bec7b36517c61e0"},"references":{"count":27,"sample":[{"doi":"","year":2008,"title":"2008, MNRAS, 390, 759","work_id":"774fdc18-2148-4e4b-97a0-70915d7f8253","ref_index":1,"cited_arxiv_id":"","is_internal_anchor":false},{"doi":"","year":2013,"title":"Baumgardt, H., Parmentier, G., Anders, P., & Grebel, E. 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C., et al. 2025, A&A, 695, L9","work_id":"8a56bf1b-799d-4cdd-9f03-d2b48a7f9b48","ref_index":5,"cited_arxiv_id":"","is_internal_anchor":false}],"resolved_work":27,"snapshot_sha256":"8124c3d0178349df56e6f8960f8fec550ba8145d40ad31fa5367154204445a75","internal_anchors":0},"formal_canon":{"evidence_count":2,"snapshot_sha256":"bed2812aec025bf07d339291d87244f3e46fe88a7edd59aab705965f095c063c"},"author_claims":{"count":0,"strong_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"builder_version":"pith-number-builder-2026-05-17-v1"}