{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"ee8e034284f9ab38bd5a24e6246113b02ba1ead508749a43b10b53ac77d1f638","created":"2026-10-03T07:17:54Z","files":[],"origin":{"assisted_by":[],"kind":"seed"},"parents":["5475cf5dc5b1a72283d26dc95dc6e00d7ea4e00096a7c6492e409a1816eeb011"],"salt":"1f08d4826f69e54f85dcbb6a12449dcbab75974f9af40af760b4fc5525cafcca","schema":"pubphys.record/2","site":"pubphys.com","target":null,"type":"revision"},"content":{"answer_type":"value","assisted_by":[],"external_id":"astro.cosmic-ray-origins.galactic-extragalactic-transition","kind":"well-posed","literature_status":"contested","n":"1","parents":[],"plain":"Below some energy cosmic rays come from our own galaxy and above it from other galaxies; whether the handover happens near $1e17\\,\\mathrm{eV}$ or near $5e18\\,\\mathrm{eV}$ (the ankle, where the spectrum flattens) is unsettled.","posed_since":"","precise":"Determine the energy at which the extragalactic flux exceeds the Galactic flux, using the iron knee near $8e16\\,\\mathrm{eV}$, the second knee near $1e17\\text{ to }3e17\\,\\mathrm{eV}$, the ankle near $5e18\\,\\mathrm{eV}$, the energy dependence of the mean shower depth $X_{\\mathrm{max}}$ and its spread (lightest composition near $2e18\\,\\mathrm{eV}$), and the change of the dipole direction from near the Galactic center below $1e18\\,\\mathrm{eV}$ to away from it above $8e18\\,\\mathrm{eV}$. Answer: the transition energy and the Galactic component spectrum, including whether a second Galactic population beyond the knee sources is required.","problem_ref":null,"references":"","settled_by":"Mass-resolved spectra and anisotropies from $1e16 \\text{ to } 1e19\\,\\mathrm{eV}$ with overlapping detectors, fit by a two-population model with propagation.","status_note":"","title":"At what energy do extragalactic cosmic rays take over from Galactic ones?","topic_ref":"f43296f47e522e13af620cd00eea18765794669715c801e5fb034a7d89800844"},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"a6a796561663976f3ddf558ae535abc711ec941b5c6dd67689033d9388daf318","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"2e0e506eb6fc33c93227cd934e80aba94c4a23487e7d12e197cad05dab11798d","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"OSTB9V6RkL03sxoU6dnK41db71i9HZl1pgdo22TKnN6yvx8ff5mR1QIrs7kNFriS-iKzhC5HYuFSBwYOtDENAQ"},"schema":"pubphys.envelope/1"},"record_hash":"a6a796561663976f3ddf558ae535abc711ec941b5c6dd67689033d9388daf318","leaf_index":513}