{"paper":{"title":"Revisiting the He II to H I ratio in the Intergalactic Medium","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"astro-ph.CO","authors_text":"Paris), Patrick Petitjean (IAP, Pune), Raghunathan Srianand (IUCAA, Sowgat Muzahid (IUCAA","submitted_at":"2010-08-24T20:00:05Z","abstract_excerpt":"We estimate the He II to H I column density ratio, \\eta = N(He II)/N(H I), in the intergalactic medium towards the high redshift (z_{em} = 2.885) bright quasar QSO HE 2347-4342 using Voigt-profile fitting of the H I transitions in the Lyman series and the He II Lyman-$\\alpha$ transition as observed by the FUSE satellite. In agreement with previous studies, we find that $\\eta > 50$ in most of the Lyman-$\\alpha$ forest except in four regions where it is much smaller ($\\eta \\sim 10-20$) and therefore inconsistent with photo-ionization by the UV background flux. We detect O VI and C IV absorption "},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1008.4132","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"}