{"paper":{"title":"Is GBT 1355+5439 a dark galaxy?","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["astro-ph.CO"],"primary_cat":"astro-ph.GA","authors_text":"2), (2) Kapteyn Astronomical Institute, 3) ((1) Netherlands Institute for Radio Astronomy (ASTRON), (3) Astrophysics, Cosmology, Department of Astronomy, Dwingeloo, G.H. Heald (1), Gravity Centre (ACGC), South Africa), T.A. Oosterloo (1, The Netherlands, University of Cape Town, University of Groningen, W.J.G. de Blok (1","submitted_at":"2013-06-26T06:58:00Z","abstract_excerpt":"We present HI imaging of GBT 1355+5439 performed with the Westerbork Synthesis Radio Telescope. This is a dark HI object recently discovered close to the nearby galaxy M101. We find GBT 1355+5439 to be an HI cloud 5x3 arcmin in size. The total HI image and the kinematics show that the cloud consists of condensations that have small (~10 km/s) motions with respect to each other. The column densities of the HI are low; the observed peak value is 7.1x10^{19} cm^{-2}. The velocity field shows a mild velocity gradient over the body of GBT 1355+5439, possibly due to rotation, but it may also indicat"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1306.6148","kind":"arxiv","version":2},"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"}