{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"a204860d168c3a94d2f670ee5fd57c9d42bd3c7b74f6885eac27e72bf9a33edf","created":"2026-10-03T07:17:55Z","files":[],"origin":{"assisted_by":[],"kind":"seed"},"parents":["5475cf5dc5b1a72283d26dc95dc6e00d7ea4e00096a7c6492e409a1816eeb011"],"salt":"358cf25e8fe76d5fb777827d6c83a6551b0ef9a1662ddc3d248c37e4223b33f4","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":"1","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 $\\sim 2e52\\ \\mathrm{erg}$, 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":null,"references":"","settled_by":"Beaming-corrected jet energies above $2e52\\,\\mathrm{erg}$ 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":"d34ff2cb4f455ed6abcd7339be502ac934cb4f47f2fd2df51ba89febba9c8dd6"},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"80a9eb0c6f00c33e686d5766a1873762a0a09545469c2342649d3c3a08342879","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"09bbd05c29956ee3a865be7caefee6b8a04eaa11e280be9917b8d3ebfab92675","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"7fQbyVo9kOvTcxRficJBpfLv2QDmHVKgt3rWCycEN8VK58LUZQnVD2uf9nnqIP5sPO540Rrpwso4NjKbjNjGBQ"},"schema":"pubphys.envelope/1"},"record_hash":"80a9eb0c6f00c33e686d5766a1873762a0a09545469c2342649d3c3a08342879","leaf_index":544}