{"paper":{"title":"Constraints on QSO emissivity using H I and He II Lyman alpha forest","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["astro-ph.CO"],"primary_cat":"astro-ph.GA","authors_text":"Vikram Khaire","submitted_at":"2017-02-13T19:00:06Z","abstract_excerpt":"The spectrum of cosmic ultraviolet background radiation at He II ionizing energies (E > 4 Ryd) is important to study the He II reionization, thermal history of the intergalactic medium (IGM) and metal lines observed in QSO absorption spectra. It is determined by the emissivity of QSOs at E > 4 Ryd obtained from their observed luminosity functions and the mean spectral energy distribution (SED). The SED is approximated as a power-law at energies E > 1 Ryd, $f_E \\propto E^{\\alpha}$, where the existing observations constrain the power-law index $\\alpha$ only up to ~2.3 Ryd. Here, we constrain $\\a"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1702.03937","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"}