{"paper":{"title":"Quantified HI Morphology IV: The Merger Fraction and Rate in WHISP","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"astro-ph.CO","authors_text":"((1) European Space Agency, 2), (2) Astrophysics, (3) Space Telescope Science Institute, (4) Department of Physics, A. Bouchard (4), Astronomy Department, B. W. Holwerda (1, Cosmology, ESTEC, Gravity Centre (ACGC), K. J. van der Heyden (2), McGill University), N. Pirzkal (3), S-L. Blyth (2), University of Cape Town, W.J.G. de Blok (2)","submitted_at":"2011-04-17T10:36:14Z","abstract_excerpt":"The morphology of the atomic hydrogen (HI) disk of a spiral galaxy is the first component to be disturbed by a gravitational interaction such as a merger between two galaxies. We use a simple parametrisation of the morphology of HI column density maps of Westerbork HI Spiral Project (WHISP) to select those galaxies that are likely undergoing a significant interaction. Merging galaxies occupy a particular part of parameter space defined by Asymmetry (A), the relative contribution of the 20% brightest pixels to the second order moment of the column density map (M20) and the distribution of the s"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1104.3297","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"}