{"paper":{"title":"Upper limits on CH$_3$OH in the HD 163296 protoplanetary disk: evidence for a low gas-phase CH$_3$OH/H$_2$CO ratio","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["astro-ph.GA"],"primary_cat":"astro-ph.SR","authors_text":"C. Qi, C. Walsh, E.C. Fayolle, J.M. Carpenter, K.I. \\\"Oberg, L.I. Cleeves, M.R. Hogerheijde, M.T. Carney, V.V. Guzm\\'an","submitted_at":"2019-01-09T12:21:42Z","abstract_excerpt":"Methanol (CH$_3$OH) is at the root of organic ice chemistry in protoplanetary disks. However, its weak emission has made detections difficult. To date, gas-phase CH$_3$OH has been detected in only one Class II disk, TW Hya. We use the Atacama Large Millimeter/submillimeter Array (ALMA) to search for a total of four CH$_3$OH emission lines in bands 6 and 7 toward the disk around the young Herbig Ae star HD 163296. The disk-averaged column density of methanol and its related species formaldehyde (H$_2$CO) are estimated assuming optically thin emission in local thermodynamic equilibrium. We compa"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1901.02689","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"}