{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"bbb845a05817c00a9ef5c2f8554ba05c10f4030f162d26db0590557c8c1fefa3","created":"2026-10-15T23:43:22Z","files":[],"origin":{"assisted_by":[],"kind":"seed"},"parents":["80a9eb0c6f00c33e686d5766a1873762a0a09545469c2342649d3c3a08342879","ce59fb6cd812fc05906d0c60a71c75ea22bc686bcf38e7c3ef7010834d98ee7b"],"salt":"b2176fff82dd9f4c61250018e21c2fc65272f71d68e5a9c86b3e59560a16a30b","schema":"pubphys.record/2","site":"pubphys.com","target":null,"type":"revision"},"content":{"answer_type":"identification","assisted_by":[],"external_id":"astro.grb-engines-jets.engine-identity","kind":"well-posed","literature_status":"contested","n":"2","parents":[],"plain":"The engine could be a fast-spinning, highly magnetized neutron star or a newborn black hole swallowing a disk; each leaves different marks in the X-ray afterglow.","posed_since":"","precise":"For long and short GRBs, determine whether the engine is a millisecond proto-magnetar (rotational energy at most $\\sim 2 \\times 10^{52}\\ \\mathrm{erg}$, X-ray plateau followed by $L\\sim t^{-2}$ decay) or a hyperaccreting black hole (Blandford-Znajek power with fall-back accretion L ~ t^-5/3). Answer: per-burst engine classification with energy budget, using X-ray plateaus, extended emission and late flares.","problem_ref":"80a9eb0c6f00c33e686d5766a1873762a0a09545469c2342649d3c3a08342879","references":"","settled_by":"Beaming-corrected jet energies above $2 \\times 10^{52}\\,\\mathrm{erg}$ excluding magnetars for a burst subclass, and gravitational-wave detection of the post-merger remnant for short bursts.","status_note":"","title":"Millisecond magnetar or accreting black hole as GRB engine?","topic_ref":null},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"62fae8231f46bc27e2292b5cfc586dd37ef359c66cd539d7a8d1c6cab6517f49","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"7a9c13ac5730d7eec844d5d04c957ef085b2e1b7260f11276aa4b8c3078d6099","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"QYgwtWmJ9s0eROiHWbY6WZ5OyLeAklI7m1F7l6seeIcUtOCYH8pyNcPJK7JGZIvCKXoEYuBnfHOplawCcXsdAg"},"schema":"pubphys.envelope/1"},"record_hash":"62fae8231f46bc27e2292b5cfc586dd37ef359c66cd539d7a8d1c6cab6517f49","leaf_index":2366}