{"paper":{"title":"A Spectroscopic Survey of X-ray Selected AGN in the Northern XMM-XXL Field","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"astro-ph.GA","authors_text":"Andrea Merloni, Antonis Georgakakis, Axel Schwope, Eric Aubourg, Isabelle P\\^aris, Johannes Buchner, Kirpal Nandra, Mara Salvato, Marcella Brusa, Marie-Luise Menzel, Patrick Petitjean, Tom Dwelly, William Nielsen Brandt","submitted_at":"2015-11-24T21:00:01Z","abstract_excerpt":"This paper presents a survey of X-ray selected active galactic nuclei (AGN) with optical spectroscopic follow-up in a $\\sim 18\\, \\rm{deg^2}$ area of the equatorial XMM-XXL north field. A sample of 8445 point-like X-ray sources detected by XMM-Newton above a limiting flux of $F_{\\rm 0.5-10\\, keV} > 10^{-15} \\rm\\,erg\\, cm^{-2}\\, s^{-1}$ was matched to optical (SDSS) and infrared (WISE) counterparts. We followed up 3042 sources brighter than $r=22.5$ mag with the SDSS BOSS spectrograph. The spectra yielded a reliable redshift measurement for 2578 AGN in the redshift range $z=0.02-5.0$, with $0.5-"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1511.07870","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"}