{"paper":{"title":"Seeking the Ultraviolet Ionizing Background at z~3 with the Keck Telescope","license":"","headline":"","cross_cats":[],"primary_cat":"astro-ph","authors_text":"Andrew J. Bunker, Berkeley), Francine R. Marleau, James R. Graham (Department of Astronomy, University of California","submitted_at":"1998-08-11T23:57:05Z","abstract_excerpt":"We describe the initial results of a deep long-slit emission line search for redshifted (2.7<z<4.1) Lyman-alpha. These observations are used to constrain the fluorescent Ly-alpha emission from the population of clouds whose absorption produces the higher-column-density component of the Ly-alpha forest in quasar spectra. We use the results to set an upper limit on the ultraviolet ionizing background. Our spectroscopic data obtained with the Keck II telescope at lambda/(Delta lambda FWHM)~2000 reveals no candidate Ly-alpha emission over the wavelength range of 4500-6200 Ang along a 3 arcmin slit"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"astro-ph/9808111","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"}