{"paper":{"title":"X-ray spectroscopy of the z=6.4 quasar J1148+5251","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["astro-ph.CO"],"primary_cat":"astro-ph.GA","authors_text":"Andrea Ferrara, Andrea Pallottini, Chiara Feruglio, Cristian Vignali, Enrico Piconcelli, Fabrizio Fiore, Luca Zappacosta, Maria Carmela Orofino, Roberto Gilli, Roberto Maiolino, Roberto Neri, Simona Gallerani","submitted_at":"2017-02-23T19:00:01Z","abstract_excerpt":"We present the 78-ks Chandra observations of the $z=6.4$ quasar SDSS J1148+5251. The source is clearly detected in the energy range 0.3-7 keV with 42 counts (with a significance $\\gtrsim9\\sigma$). The X-ray spectrum is best-fitted by a power-law with photon index $\\Gamma=1.9$ absorbed by a gas column density of $\\rm N_{\\rm H}=2.0^{+2.0}_{-1.5}\\times10^{23}\\,\\rm cm^{-2}$. We measure an intrinsic luminosity at 2-10 keV and 10-40 keV equal to $\\sim 1.5\\times 10^{45}~\\rm erg~s^{-1}$, comparable with luminous local and intermediate-redshift quasar properties. Moreover, the X-ray to optical power-la"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1702.07349","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"}