{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"0faeeef61d5e8b2b059825d15fd616dd85df38dfe502553516f00011c8b37f95","created":"2026-10-15T23:43:22Z","files":[],"origin":{"assisted_by":[],"kind":"seed"},"parents":["2f15845d6566c93410008a8f7c998e19432acc2b552908ed9e77c8147a8763af","ce59fb6cd812fc05906d0c60a71c75ea22bc686bcf38e7c3ef7010834d98ee7b"],"salt":"4bb84490834cd77f1ec1f346f7a0d7501c89928363c89f699a1a9d7f9f0bfdbd","schema":"pubphys.record/2","site":"pubphys.com","target":null,"type":"revision"},"content":{"answer_type":"identification","assisted_by":[],"external_id":"astro.fast-radio-bursts.old-hosts","kind":"phenomenon","literature_status":"open","n":"2","parents":[],"plain":"Some bursts come from a globular cluster (a ball of stars about $10^{10}\\,\\mathrm{years}$ old) or from galaxies that stopped forming stars long ago, where newborn magnetars should be absent.","posed_since":"2022","precise":"FRB 20200120E lies in a globular cluster of M81 and other FRBs localize to quiescent galaxies. Determine the formation channel of the active sources there (accretion-induced collapse of white dwarfs, white-dwarf or neutron-star mergers, accreting compact binaries) and its rate per unit stellar mass. Answer: a channel whose rate matches the observed fraction of FRBs in old hosts.","problem_ref":"2f15845d6566c93410008a8f7c998e19432acc2b552908ed9e77c8147a8763af","references":"","settled_by":"Precise localizations of a statistical sample of FRBs in old environments, with the rate per stellar mass compared to channel predictions.","status_note":"2025: the repeating source FRB 20240209A was localized to the outskirts of a quiescent elliptical galaxy.","title":"How do FRB sources arise in old stellar populations?","topic_ref":null},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"ebe14b555b3c3e5bc093041ea152f5d10af765a30b3bf96fe6b2fab4a7eb38f7","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"9074fba345efb04e81d0a178bf295e95d3ad05b4c5d30060f4d29d37ed405909","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"x4NBbUvMq6UGpRVktVEYIW32Qv0JVtpo1HfTSU0n-BOwDaSHfOu6mXMUo2GWYE_f3swDltliIJTg69TsWYXwCA"},"schema":"pubphys.envelope/1"},"record_hash":"ebe14b555b3c3e5bc093041ea152f5d10af765a30b3bf96fe6b2fab4a7eb38f7","leaf_index":2346}