{"paper":{"title":"CO-to-H$_2$ conversion factor and grain size distribution through the analysis of $\\alpha_\\mathrm{CO}$-$q_\\mathrm{PAH}$ relation","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"astro-ph.GA","authors_text":"Adam K. Leroy, Eric W. Koch, Hiroyuki Hirashita, I-Da Chiang, Jeremy Chastenet, Karin M. Sandstrom, Thomas G. Williams, Yu-Hsuan Teng","submitted_at":"2024-12-05T08:01:00Z","abstract_excerpt":"The CO-to-H$_2$ conversion factor ($\\alpha_\\mathrm{CO}$) is expected to vary with dust abundance and grain size distribution through the efficiency of shielding gas from CO-dissociation radiation. We present a comprehensive analysis of $\\alpha_\\mathrm{CO}$ and grain size distribution for nearby galaxies, using the PAH fraction ($q_\\mathrm{PAH}$) as an observable proxy of grain size distribution. We adopt the resolved observations at 2-kpc resolution in 42 nearby galaxies, where $\\alpha_\\mathrm{CO}$ is derived from measured metallicity and surface densities of dust and HI assuming a fixed dust-"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2412.03954","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/2412.03954/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"}