{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"9597f4b217aaf0ce58af9a324e96444e9882b5f5cf301f97b38d9adda7642067","created":"2026-10-03T07:17:54Z","files":[],"origin":{"assisted_by":[],"kind":"seed"},"parents":["5475cf5dc5b1a72283d26dc95dc6e00d7ea4e00096a7c6492e409a1816eeb011","c1e2a1cd2e6fbd4139fbfdc11f91c70a9fb7e50f5c04e9ce96b450ca2deceb7a"],"salt":"89433a573fdcc3601e23d34510229706ee5219001839f722424cadff744da310","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":"1","parents":[{"note":"","parent_revision":"c1e2a1cd2e6fbd4139fbfdc11f91c70a9fb7e50f5c04e9ce96b450ca2deceb7a","relation":"special_case"}],"plain":"Some bursts come from a globular cluster (a ball of stars about $1e10\\,\\mathrm{years}$ 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":null,"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":"e34915880c8b4fcf234950c4bc4b644f158dd59b4baa5d82a78b1c9c3951edf9"},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"2f15845d6566c93410008a8f7c998e19432acc2b552908ed9e77c8147a8763af","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"5d2a4223252f44501883cb7e0228a21e6df5fcb48aed4c760ed89457f0b39794","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"L67x97XH8C_PZvJ9mSZQsogQqoltAj6BHRP86aVoNVNQ_vlSqNcTW2-hg5GtkQ4RKMQCKessE1kmweCwRH_JDw"},"schema":"pubphys.envelope/1"},"record_hash":"2f15845d6566c93410008a8f7c998e19432acc2b552908ed9e77c8147a8763af","leaf_index":527}