{"paper":{"title":"Optical Spectroscopy of Candidates for Quasars at 3<z<5.5 from the XMM-Newton X-ray survey. A distant X-ray Quasar at z=5.08","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["astro-ph.IM"],"primary_cat":"astro-ph.GA","authors_text":"(2) Institute of Solar-Terrestrial Physics of Siberian brunch RAS), A.L. Amvrosov (2), G.A. Khorunzhev (1), M.V. Eselevich (2) ((1) Space Research Institute of RAS, R.A. Burenin (1), S.Yu. Sazonov (1)","submitted_at":"2017-01-30T20:37:53Z","abstract_excerpt":"We present the results of optical spectroscopy for 19 quasar candidates at photometric redshifts $\\zphot \\gtrsim 3$, \\Nobs \\ of which enter into the Khorunzhev et al.~(2016) catalog (K16). This is a catalog of quasar candidates and known type 1 quasars selected among the X-ray sources of the \\textit{3XMM-DR4}catalog of the XMM-Newton serendipitous survey. We have performed spectroscopy for a quasi-random sample of new candidates at the 1.6-m \\Azt \\ telescope of the Sayan Solar Observatory and the 6-m BTA telescope of the Special Astrophysical Observatory. The spectra at \\Azt \\ were taken with "},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1701.08820","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"}