{"paper":{"title":"NGC 5548 in a Low-Luminosity State: Implications for the Broad-Line Region","license":"","headline":"","cross_cats":[],"primary_cat":"astro-ph","authors_text":"10) (1. The Ohio State University, 10. Research Center for the Early Universe, 2. University of St. Andrews, 3), 3. University of Michigan, 4), 4. Michigan State University, 5. Institute of Astronomy, 6), 6. Herzberg Institute of Astrophysics, 7. Crimean Astrophysical Observatory, 8), 8. Isaak Newton Institute of Chile, 9. Steward Observatory, Bradley M. Peterson (1), Charles Kuehn (1, Christopher A. Onken (1, Douglas O. Richstone (3), Edward M. Cackett (2, Himel Ghosh (1), Jeffrey K. J. Fogel (3), Keith D. Horne (2), Kelly D. Denney (1), Marianne Vestergaard (9), Matthew G. Walker (3), Matthias Dietrich (1), Misty C. Bentz (1), Richard W. Pogge (1), Sergey G. Sergeev (7, Takeo Minezaki (5), University of Tokyo, University of Tokyo), Vladimir I. Pronik (7, Yuzuru Yoshii (5","submitted_at":"2007-02-23T21:00:38Z","abstract_excerpt":"We describe results from a new ground-based monitoring campaign on NGC 5548, the best studied reverberation-mapped AGN. We find that it was in the lowest luminosity state yet recorded during a monitoring program, namely L(5100) = 4.7 x 10^42 ergs s^-1. We determine a rest-frame time lag between flux variations in the continuum and the Hbeta line of 6.3 (+2.6/-2.3) days. Combining our measurements with those of previous campaigns, we determine a weighted black hole mass of M_BH = 6.54 (+0.26/-0.25) x 10^7 M_sun based on all broad emission lines with suitable variability data. We confirm the pre"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"astro-ph/0702644","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"}