{"paper":{"title":"Was the Universe neutral beyond redshift six?","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"astro-ph","authors_text":"A. Ferrara, Choudhury T. Roy, R. Salvaterra, S. Gallerani, X. Fan","submitted_at":"2008-01-30T14:10:08Z","abstract_excerpt":"We provide measurements of the neutral hydrogen fraction xHI at z~6, by comparing semi-analytical models of the Lyalpha forest with observations of high-z quasars and Gamma Ray Bursts absorption spectra. We analyze the transmitted flux in a sample of 17 QSOs spectra at 5.74<zem<6.42 studying separately the narrow transmission windows (peaks) and the wide dark portions (gaps) in the observed absorption spectra. By comparing the statistics of these spectral features with our models, we conclude that xHI evolves smoothly from 10^{-4.4} at z=5.3 to 10^{-4.2} at z=5.6, with a robust upper limit xHI"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"0801.4674","kind":"arxiv","version":2},"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"}