{"paper":{"title":"Magnetized Sources of Ultra-high Energy Nuclei and Extragalactic Origin of the Ankle","license":"","headline":"","cross_cats":["hep-ph"],"primary_cat":"astro-ph","authors_text":"Eric Armengaud (APC, GReCO, Guenter Sigl, Paris)","submitted_at":"2005-07-28T16:56:24Z","abstract_excerpt":"It has recently been suggested that ultra-high energy cosmic rays could have an extragalactic origin down to the \"second knee\" at ~4x10^{17}eV. In this case the \"ankle\" or \"dip\" at ~5x10^{18}eV would be due to pair production of extragalactic protons on the cosmic microwave background which requires an injection spectrum of about E^{-2.6}. It has been pointed out that for injection of a mixed composition of nuclei a harder injection spectrum \\~E^{-2.2} is required to fit the spectra at the highest energies and a galactic component is required in this case to fit the spectrum below the ankle, u"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"astro-ph/0507656","kind":"arxiv","version":1},"verdict":{"id":null,"model_set":{},"created_at":null,"strongest_claim":"","one_line_summary":"","pipeline_version":null,"weakest_assumption":"","pith_extraction_headline":""},"references":{"count":0,"sample":[],"resolved_work":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57","internal_anchors":0},"formal_canon":{"evidence_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"author_claims":{"count":0,"strong_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"builder_version":"pith-number-builder-2026-05-17-v1"}