{"paper":{"title":"Beyond Mergers: the Role of Metallicity in Forming a Reservoir of Massive and Detached Binary Black Hole Systems","arxiv_id":"2610.20736","primary_cat":"astro-ph.SR","submitted_at":"2026-10-14T18:00:46+00:00","version_compiled":"v1"},"notice":"Every quoted sentence is the authors' text from the arXiv listing abstract. Labels and probabilities are the outputs of classifier-1.13.0 on the question bank abstract-p1-20260923, exactly as returned. No sentence in this record was written by a language model.","schema":"pith.compiled-record/v0","status":"compiled","abstract":{"source":"arXiv listing abstract v1","sentences":[{"i":0,"p":1.0,"id":"s0","own":false,"role":"background","text":"Isolated binary evolution is a key pathway to forming binary black hole (BBH) mergers.","hedge":{"p":1.0,"label":"asserted"},"own_p":0.05,"main_claim_p":0.03,"quantitative":false,"quantitative_p":0.03,"role_probabilities":{"gap":0.0,"method":0.0,"result":0.0,"background":1.0,"limitation":0.0,"future_work":0.0,"contribution":0.0,"interpretation":0.0}},{"i":1,"p":0.59,"id":"s1","own":false,"role":"gap","text":"However, the observed gravitational-wave population indicates it may not account for all mergers, especially those with high primary black hole mass ($\\gtrsim 30 M_{\\odot}$).","hedge":{"p":1.0,"label":"hedged_possibility"},"own_p":0.08,"main_claim_p":0.04,"quantitative":true,"quantitative_p":0.96,"role_probabilities":{"gap":0.59,"method":0.0,"result":0.0,"background":0.41,"limitation":0.0,"future_work":0.0,"contribution":0.0,"interpretation":0.0}},{"i":2,"p":0.98,"id":"s2","own":true,"role":"method","text":"Using the binary population synthesis code \\texttt{POSYDON}, we simulate populations of binary systems at eight metallicities from $10^{-4}$ to $2\\,Z_\\odot$ and classify each BH-forming binary as a merging BBH, a detached BBH, or a system disrupted during BH formation.","hedge":{"p":0.97,"label":"asserted"},"own_p":0.97,"main_claim_p":0.03,"quantitative":true,"quantitative_p":0.97,"role_probabilities":{"gap":0.0,"method":0.98,"result":0.0,"background":0.0,"limitation":0.0,"future_work":0.0,"contribution":0.02,"interpretation":0.0}},{"i":3,"p":1.0,"id":"s3","own":true,"role":"result","text":"We find that metallicity shapes these populations differently, especially for high BH masses ($\\gtrsim 25 M_{\\odot}$).","hedge":{"p":1.0,"label":"asserted"},"own_p":0.95,"main_claim_p":0.14,"quantitative":true,"quantitative_p":0.72,"role_probabilities":{"gap":0.0,"method":0.0,"result":1.0,"background":0.0,"limitation":0.0,"future_work":0.0,"contribution":0.0,"interpretation":0.0}},{"i":4,"p":1.0,"id":"s4","own":true,"role":"result","text":"At lower metallicities, between $10^{-2}$ and $0.45\\,Z_\\odot$, massive BHs continue to form but become increasingly unlikely to merge: the number of massive merging BBHs declines sharply, while the detached population remains abundant.","hedge":{"p":1.0,"label":"asserted"},"own_p":0.94,"main_claim_p":0.2,"quantitative":true,"quantitative_p":0.97,"role_probabilities":{"gap":0.0,"method":0.0,"result":1.0,"background":0.0,"limitation":0.0,"future_work":0.0,"contribution":0.0,"interpretation":0.0}},{"i":5,"p":1.0,"id":"s5","own":true,"role":"result","text":"For $25$--$35\\,M_\\odot$ BHs, the detached-to-merging ratio increases by more than two orders of magnitude across this metallicity range.","hedge":{"p":1.0,"label":"asserted"},"own_p":0.95,"main_claim_p":0.12,"quantitative":true,"quantitative_p":0.99,"role_probabilities":{"gap":0.0,"method":0.0,"result":1.0,"background":0.0,"limitation":0.0,"future_work":0.0,"contribution":0.0,"interpretation":0.0}},{"i":6,"p":1.0,"id":"s6","own":true,"role":"result","text":"After weighting by cosmic star formation, massive BHs are found predominantly in detached binaries with orbital periods $\\gtrsim 10^2$ days.","hedge":{"p":1.0,"label":"asserted"},"own_p":0.95,"main_claim_p":0.15,"quantitative":true,"quantitative_p":0.97,"role_probabilities":{"gap":0.0,"method":0.0,"result":1.0,"background":0.0,"limitation":0.0,"future_work":0.0,"contribution":0.0,"interpretation":0.0}},{"i":7,"p":1.0,"id":"s7","own":true,"role":"interpretation","text":"Therefore, isolated binary evolution can form massive BBHs even if it rarely produces massive BBH mergers, leaving behind a massive and detached population that may be driven to merger through dynamical interactions in dense stellar environments.","hedge":{"p":0.78,"label":"hedged_possibility"},"own_p":0.7,"main_claim_p":0.88,"quantitative":false,"quantitative_p":0.08,"role_probabilities":{"gap":0.0,"method":0.0,"result":0.0,"background":0.0,"limitation":0.0,"future_work":0.0,"contribution":0.0,"interpretation":1.0}}]},"compiled":{"main_claim":{"p":1.0,"text":"Therefore, isolated binary evolution can form massive BBHs even if it rarely produces massive BBH mergers, leaving behind a massive and detached population that may be driven to merger through dynamical interactions in dense stellar environments.","location":"abstract s7","hedge_strength":{"p":0.78,"label":"hedged possibility"}},"provenance":{"route":{"via":"TypeSafe API","model":"classifier-1.13.0","endpoint":"https://api.typesafe.ai/v1/systemone","provider":"TypeSafe"},"packing":"one request per 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\\texttt{POSYDON}, we simulate populations of binary systems at eight metallicities from $10^{-4}$ to $2\\,Z_\\odot$ and classify each BH-forming binary as a merging BBH, a detached BBH, or a system disrupted during BH formation.","location":"abstract s2"}},"coverage":{"tier":"abstract","levels_run":["P abstract"],"not_examined":["full text","figures and tables","references and citing sentences","relations to other papers"],"sources_read":["arXiv listing abstract v1"],"levels_not_run":["S sections","T body sentences","C citations","R cross-paper relations"],"sentences_examined":8,"sentences_in_abstract":8},"measured_accuracy":{"url":"https://pith.science/accuracy","measured_on":"2026-10-02","method":"two independent model families labelled a fresh random sample blind; the figure is how often the published label matches their 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