{"paper":{"title":"The bar pattern speed of NGC 4431","license":"","headline":"","cross_cats":[],"primary_cat":"astro-ph","authors_text":"(2) IAC, (3) University of Washington, 4), (4) Brooks Prize Fellow, (5) University of Texas at Austin, (6) Research School of Astronomy, A. Pizzella (1), Astrophysics, Australia), E.M. Corsini (1), F.D. Barazza (5), H. Jerjen (6) ((1) Universita` di Padova, Italy, J.A.L. Aguerri (2), La Laguna, Seattle, Spain, TX, USA, Victor P. Debattista (3, WA, Weston","submitted_at":"2007-03-13T19:27:53Z","abstract_excerpt":"We present surface photometry and stellar kinematics of NGC 4431, a barred dwarf galaxy in the Virgo cluster undergoing a tidal interaction with one of its neighbors, NGC 4436. We measured its bar pattern speed using the Tremaine-Weinberg method, and derived the ratio of the corotation radius, D_L, to the bar semi-major axis, a_B. We found D_L/a_B=0.6^{+1.2}_{-0.4} at 99% confidence level. Albeit with large uncertainty, the probability that the bar ends close to its corotation radius (i.e., 1.0 \\leq D_L/a_B \\leq 1.4) is about twice as likely as that the bar is much shorter than corotation radi"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"astro-ph/0703332","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"}