{"paper":{"title":"A Population of X-ray Weak Quasars: PHL 1811 Analogs at High Redshift","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["astro-ph.GA","astro-ph.HE"],"primary_cat":"astro-ph.CO","authors_text":"Dennis W. Just, Donald P. Schneider, Gordon T. Richards, Jianfeng Wu, Ohad Shemmer, Patrick B. Hall, Robert R. Gibson, Sarah J. Schmidt, W. N. Brandt","submitted_at":"2011-04-19T20:00:03Z","abstract_excerpt":"We report the results from Chandra and XMM-Newton observations of a sample of 10 type 1 quasars selected to have unusual UV emission-line properties (weak and blueshifted high-ionization lines; strong UV Fe emission) similar to those of PHL 1811, a confirmed intrinsically X-ray weak quasar. These quasars were identified by the Sloan Digital Sky Survey at high redshift (z~2.2); eight are radio quiet while two are radio intermediate. All of the radio-quiet PHL 1811 analogs are notably X-ray weak by a mean factor of ~13. These sources lack broad absorption lines and have blue UV/optical continua,"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1104.3861","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"}