{"paper":{"title":"Extreme quasars at high redshift","license":"http://creativecommons.org/licenses/by/4.0/","headline":"","cross_cats":[],"primary_cat":"astro-ph.GA","authors_text":"A. Del Olmo, C. A. Negrete, D. Dultzin, J. Perea, J. W. Sulentic, M. D Onofrio, M. L. Mart{\\i}nez-Aldama, P. Marziani","submitted_at":"2018-07-29T06:13:31Z","abstract_excerpt":"Context:Quasars radiating at extreme Eddington ratios (xA) are likely a prime mover of galactic evolution and have been hailed as potential distance indicators. Their properties are still scarcely known.\n  Aims:We test the effectiveness of the selection criteria defined on the 4D Eigenvector 1 (4DE1) for identifying xA sources. We provide a quantitative description of their UV spectra in the redshift range 2<z<2.9.\n  Methods:19 extreme quasar candidates were identified using 4DE1 selection criteria applied to SDSS spectra: AlIII1860/SiIII]1892>0.5 and CIII]1909/SiIII]1892<1. The emission line "},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1807.11006","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"}