{"paper":{"title":"Modeling the UV-photon irradiation of CS$_2$-bearing ices in the laboratory with the pyRate gas-grain astrochemical code. New insights into the missing sulfur problem","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"Nondiffusive chemistry must be included to reproduce the sulfur-bearing species formed in UV-irradiated CO2:CS2 ices at 10 K.","cross_cats":[],"primary_cat":"astro-ph.GA","authors_text":"A. Fuente, A. Taillard, D. Navarro-Almaida, G.M. Mu\\~noz Caro, O. Sipil\\\"a, R. Mart\\'in-Dom\\'enech, W. Riedel","submitted_at":"2026-05-05T13:11:04Z","abstract_excerpt":"Observations indicate that the total abundance of S-bearing species in dense clouds is orders of magnitude lower than the cosmic sulfur abundance. Addressing this \"missing sulfur problem\" requires a combination of astronomical observations, laboratory experiments, and theoretical models. In this work, we use the pyRate astrochemical model to simulate the VUV photon irradiation of a CO$_2$:CS$_2$ ice mixture at 10 K in the laboratory, with the goal of supporting the interpretation of the experimental results and testing our current understanding of the sulfur evolution in interstellar ices. For"},"claims":{"count":4,"items":[{"kind":"strongest_claim","text":"The results indicate that nondiffusive chemistry is necessary to reproduce the formation of S-bearing species observed in the experiment.","source":"verdict.strongest_claim","status":"machine_extracted","claim_id":"C1","attestation":"unclaimed"},{"kind":"weakest_assumption","text":"That the compiled chemical network contains all relevant reactions with sufficiently accurate barriers and that the experimental product identification and quantification are free of major systematic errors.","source":"verdict.weakest_assumption","status":"machine_extracted","claim_id":"C2","attestation":"unclaimed"},{"kind":"one_line_summary","text":"The pyRate model requires nondiffusive chemistry to form observed S-bearing species in irradiated CO2:CS2 ice but overpredicts OCS, CS and SO while underpredicting SO2 and sulfur allotropes.","source":"verdict.one_line_summary","status":"machine_extracted","claim_id":"C3","attestation":"unclaimed"},{"kind":"headline","text":"Nondiffusive chemistry must be included to reproduce the sulfur-bearing species formed in UV-irradiated CO2:CS2 ices at 10 K.","source":"verdict.pith_extraction.headline","status":"machine_extracted","claim_id":"C4","attestation":"unclaimed"}],"snapshot_sha256":"0a115ed6b90de4f2862e676a92bd47f09d1463a707a3d54f78b5f2017d572369"},"source":{"id":"2605.03725","kind":"arxiv","version":1},"verdict":{"id":"85d60c9b-4272-4ec8-860a-ee66bc7d4710","model_set":{"reader":"grok-4.3"},"created_at":"2026-05-07T04:13:44.745813Z","strongest_claim":"The results indicate that nondiffusive chemistry is necessary to reproduce the formation of S-bearing species observed in the experiment.","one_line_summary":"The pyRate model requires nondiffusive chemistry to form observed S-bearing species in irradiated CO2:CS2 ice but overpredicts OCS, CS and SO while underpredicting SO2 and sulfur allotropes.","pipeline_version":"pith-pipeline@v0.9.0","weakest_assumption":"That the compiled chemical network contains all relevant reactions with sufficiently accurate barriers and that the experimental product identification and quantification are free of major systematic errors.","pith_extraction_headline":"Nondiffusive chemistry must be included to reproduce the sulfur-bearing species formed in UV-irradiated CO2:CS2 ices at 10 K."},"integrity":{"clean":true,"summary":{"advisory":0,"critical":0,"by_detector":{},"informational":0},"endpoint":"/pith/2605.03725/integrity.json","findings":[],"available":true,"detectors_run":[{"name":"ai_meta_artifact","ran_at":"2026-05-20T13:35:29.279802Z","status":"completed","version":"1.0.0","findings_count":0},{"name":"doi_title_agreement","ran_at":"2026-05-20T00:31:21.326407Z","status":"completed","version":"1.0.0","findings_count":0},{"name":"doi_compliance","ran_at":"2026-05-19T15:04:37.012385Z","status":"completed","version":"1.0.0","findings_count":0}],"snapshot_sha256":"b22073b16a3a7f95f0cf357f67d750de26db47c713e2940c239e0abc03fdc94c"},"references":{"count":74,"sample":[{"doi":"10.1093/mnras/stae2345","year":null,"title":"Ice origins of OCS and chemistry of CS _ 2 -bearing ice mantles. , keywords =. doi:10.1093/mnras/stae2345 , archivePrefix =. 2410.07736 , primaryClass =","work_id":"90e6dd66-902f-4dab-a3e8-7cdc443d8b46","ref_index":1,"cited_arxiv_id":"","is_internal_anchor":false},{"doi":"10.1086/190513","year":null,"title":"Photoelectric heating of interstellar gas. , keywords =. doi:10.1086/190513 , adsurl =","work_id":"9432d007-e2ed-4d7f-9287-b903ff8a171b","ref_index":2,"cited_arxiv_id":"","is_internal_anchor":false},{"doi":"10.3847/1538-4365/ac3131","year":null,"title":"T., Jin , M., Matis , K","work_id":"89a0b12f-3397-45e3-b0d1-21ddbdeebb5e","ref_index":3,"cited_arxiv_id":"","is_internal_anchor":false},{"doi":"","year":null,"title":"Three-Phase Chemical Models of Dense Interstellar Clouds - Gas Dust Particle Mantles and Dust Particle Surfaces. , keywords =","work_id":"6020a12e-efdc-409c-ba59-bfbd91ddde80","ref_index":4,"cited_arxiv_id":"","is_internal_anchor":false},{"doi":"10.1051/0004-6361/202451757","year":null,"title":"Measurements and simulations of rate coefficients for the deuterated forms of the H _ 2 ^ + + H _ 2 and H _ 3 ^ + + H _ 2 reactive systems at low temperature. , keywords =. doi:10.1051/0004-6361/20245","work_id":"3fa138bb-4ab7-48cc-991c-01efd7c5357b","ref_index":5,"cited_arxiv_id":"","is_internal_anchor":false}],"resolved_work":74,"snapshot_sha256":"2ae28efcedf45c80703d33dc0172780225c80596449662349a5b855b644d399e","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"}