{"paper":{"title":"Highly filamentary H{\\,\\small I} gas in the circumgalactic medium and intragalactic medium around NGC 4631","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"astro-ph.GA","authors_text":"C. Zhang, Jing Wang, Tie Liu, Xiaofeng Mai","submitted_at":"2026-06-22T02:04:30Z","abstract_excerpt":"Neutral hydrogen (H{\\,\\small I}) in the circumgalactic medium (CGM) and intergalactic medium (IGM) traces baryon cycling and galaxy evolution, yet fine filamentary substructures in diffuse CGM/IGM H{\\,\\small I} remain poorly constrained observationally. We combine FAST FEASTS single-dish and VLA THINGS interferometric H{\\,\\small I} data of the NGC 4631 group to report the first robust detection of kpc-scale filamentary structures in the CGM/IGM, with widths of $0.5$-$3.3\\ \\mathrm{kpc}$ and lengths of $6.1$-$49.8\\ \\mathrm{kpc}$. These features confirm that low-density CGM/IGM gas hosts velocity"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2606.22764","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":""},"integrity":{"clean":true,"summary":{"advisory":0,"critical":0,"by_detector":{},"informational":0},"endpoint":"/pith/2606.22764/integrity.json","findings":[],"available":true,"detectors_run":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938"},"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"}