{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"022b3c1c96548487ad4b6b6450c49495fd08ad6095cb68f6f209683bff2960c9","created":"2026-10-15T23:43:22Z","files":[],"origin":{"assisted_by":[],"kind":"seed"},"parents":["2b0d5d2ed8e499603637f1fc0a3ee48b7ad5d64e04786e66086c6d908745ec96","ce59fb6cd812fc05906d0c60a71c75ea22bc686bcf38e7c3ef7010834d98ee7b"],"salt":"2308a44f4941ce1fa7cadcb57fdf6cb0822f68c6f9b6373dcb5fbf964b51a0c4","schema":"pubphys.record/2","site":"pubphys.com","target":null,"type":"revision"},"content":{"answer_type":"identification","assisted_by":[],"external_id":"astro.r-process-sites.dominant-site","kind":"phenomenon","literature_status":"contested","n":"2","parents":[],"plain":"Neutron-star mergers, rare collapsing stars and flares from magnetars can all make r-process elements; their shares are unknown.","posed_since":"1957","precise":"Determine the fractional contributions of neutron-star mergers (including neutron star-black hole), collapsars and magnetorotational supernovae, and magnetar giant flares to the Galactic r-process mass. Constraints: binary neutron star merger rate from gravitational waves ($\\sim 10\\text{ to }1700\\,\\mathrm{Gpc}^{-3}\\,\\mathrm{yr}^{-1}$), ejecta per event ($\\sim 0.01\\text{ to }0.05\\,M_{\\mathrm{sun}}$), the $[\\mathrm{Eu}/\\mathrm{Fe}]$ versus $[\\mathrm{Fe}/\\mathrm{H}]$ trend and its scatter in metal-poor stars, and Pu-244 in deep-sea crusts. Answer: fractions with uncertainties.","problem_ref":"2b0d5d2ed8e499603637f1fc0a3ee48b7ad5d64e04786e66086c6d908745ec96","references":"","settled_by":"A tighter merger rate and kilonova yield sample from gravitational-wave events, together with direct detection of r-process signatures from collapsars.","status_note":"2025: delayed MeV emission after the 2004 SGR 1806-20 giant flare was interpreted as radioactive decay of about $10^{-6}\\,M_{\\mathrm{sun}}$ of fresh r-process matter, adding magnetar flares as a minor site.","title":"Which site dominates the r-process inventory of the Milky Way?","topic_ref":null},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"59b9aa9044311bba03157e2c4ca8a5dc6eb6d91680a61ad62634f163774e1a0b","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"59e936502a425355d17e9d60eeede910ea7784987ab9e455b593a8bff28cb5f8","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"c35JAECUgks--UyIFfaZycc33ynHz32Myc2SyW7IUl07HsLqsyRgRuDmQbXU4mYJFpSgIPd6o1ctq7XRzEnQAg"},"schema":"pubphys.envelope/1"},"record_hash":"59b9aa9044311bba03157e2c4ca8a5dc6eb6d91680a61ad62634f163774e1a0b","leaf_index":2412}