{"paper":{"title":"The colour of galaxies in distant groups","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"astro-ph.CO","authors_text":"(2) MPE, (3) Durham, (4) Swinburne, (5) OCIW, (6) McMaster, (7) CADC, A. Oemler Jr. (5), Dave Wilman (2), Garching, George Hau (4), HIA), J.S. Mulchaey (5), Laura Parker (6), Michael L. Balogh (1), Richard G. Bower (3), Sean L. McGee (1), Simon L. Morris (3), Stephen Gwyn (7) ((1) U. Waterloo","submitted_at":"2009-05-20T21:28:36Z","abstract_excerpt":"(Abridged) We present new optical and near-infrared imaging for a sample of 98 spectroscopically-selected galaxy groups at 0.25<z<0.55. We measure accurate colours for group members and the surrounding field population, statistically complete above a stellar mass limit of M=1E10 Msun. The overall colour distribution is bimodal in both the field and group samples; but at fixed luminosity the fraction of group galaxies populating the red peak is larger, by 20+/-7 per cent, than that of the field. In particular, group members with early-type morphologies, as identified in HST imaging, exhibit a t"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"0905.3401","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"}