{"paper":{"title":"Charting circumstellar chemistry of carbon-rich asymptotic giant branch stars. III. SiO and SiS abundances","license":"http://creativecommons.org/licenses/by/4.0/","headline":"SiO peak abundances in most carbon-rich AGB stars are about five times higher than in the archetype IRC+10216, while SiS abundances stay similar across the sample.","cross_cats":["astro-ph.GA"],"primary_cat":"astro-ph.SR","authors_text":"E. De Beck, H. Olofsson, L.-{\\AA}. Nyman, M. Andriantsaralaza, M. G. Rawlings, M. Maercker, M. Van de Sande, R. Unnikrishnan, S. B. Charnley, T. Danilovich, T. J. Millar, W. H. T. Vlemmings","submitted_at":"2026-05-14T18:34:02Z","abstract_excerpt":"The present understanding of C-rich AGB chemistry largely relies on observations of the archetypal carbon star IRC+10216. Current molecular abundance estimates for carbon stars are based either on single-dish spectra sampling a range of excitation conditions, or on interferometric mapping of a few lines. We aim to estimate the circumstellar abundances of SiO, SiS, and their most abundant isotopologues ($^{29}$SiO, $^{30}$SiO, $^{29}$SiS, $^{30}$SiS, and Si$^{34}$S) for a sample of five carbon stars. We derived molecular abundances using detailed 1D non-local thermodynamic equilibrium (non-LTE)"},"claims":{"count":4,"items":[{"kind":"strongest_claim","text":"We obtain good fits to the SiO and SiS line profiles, and derived well-constrained abundance profiles and reliable isotopic ratios for all sources except AFGL 3068. While the SiS peak abundances are very similar across the sample (2.0×10^{-6}-4.7×10^{-6}), we find that the SiO peak abundances of the rest of the stars are a factor of ∼5 larger than that of IRC+10216. [...] We find that the currently assumed SiS photodissociation rate in chemical models is underestimated.","source":"verdict.strongest_claim","status":"machine_extracted","claim_id":"C1","attestation":"unclaimed"},{"kind":"weakest_assumption","text":"The 1D non-LTE radiative transfer modeling with simplified (circum)stellar models accurately recovers the true radial abundance profiles and e-folding radii, despite the paper noting limitations inherent in such modeling when applied to real envelopes.","source":"verdict.weakest_assumption","status":"machine_extracted","claim_id":"C2","attestation":"unclaimed"},{"kind":"one_line_summary","text":"Derived SiO and SiS abundances for five carbon stars via 1D non-LTE RT modeling of ALMA data show SiO levels ~5x higher than IRC+10216, similar SiS, good model match for SiO but overpredicted SiS radii, implying underestimated SiS photodissociation rate.","source":"verdict.one_line_summary","status":"machine_extracted","claim_id":"C3","attestation":"unclaimed"},{"kind":"headline","text":"SiO peak abundances in most carbon-rich AGB stars are about five times higher than in the archetype IRC+10216, while SiS abundances stay similar across the sample.","source":"verdict.pith_extraction.headline","status":"machine_extracted","claim_id":"C4","attestation":"unclaimed"}],"snapshot_sha256":"49d18867a9eed407dbfee57ba40ef77da229d0fa96d5f93ab56e5a28b599ee07"},"source":{"id":"2605.15321","kind":"arxiv","version":1},"verdict":{"id":"1061ca7c-3554-414a-ab65-cc22e230540a","model_set":{"reader":"grok-4.3"},"created_at":"2026-05-19T16:06:30.902811Z","strongest_claim":"We obtain good fits to the SiO and SiS line profiles, and derived well-constrained abundance profiles and reliable isotopic ratios for all sources except AFGL 3068. While the SiS peak abundances are very similar across the sample (2.0×10^{-6}-4.7×10^{-6}), we find that the SiO peak abundances of the rest of the stars are a factor of ∼5 larger than that of IRC+10216. [...] We find that the currently assumed SiS photodissociation rate in chemical models is underestimated.","one_line_summary":"Derived SiO and SiS abundances for five carbon stars via 1D non-LTE RT modeling of ALMA data show SiO levels ~5x higher than IRC+10216, similar SiS, good model match for SiO but overpredicted SiS radii, implying underestimated SiS photodissociation rate.","pipeline_version":"pith-pipeline@v0.9.0","weakest_assumption":"The 1D non-LTE radiative transfer modeling with simplified (circum)stellar models accurately recovers the true radial abundance profiles and e-folding radii, despite the paper noting limitations inherent in such modeling when applied to real envelopes.","pith_extraction_headline":"SiO peak abundances in most carbon-rich AGB stars are about five times higher than in the archetype IRC+10216, while SiS abundances stay similar across the sample."},"integrity":{"clean":true,"summary":{"advisory":0,"critical":0,"by_detector":{},"informational":0},"endpoint":"/pith/2605.15321/integrity.json","findings":[],"available":true,"detectors_run":[{"name":"doi_title_agreement","ran_at":"2026-05-19T16:31:18.302328Z","status":"completed","version":"1.0.0","findings_count":0},{"name":"doi_compliance","ran_at":"2026-05-19T16:16:11.811850Z","status":"completed","version":"1.0.0","findings_count":0},{"name":"claim_evidence","ran_at":"2026-05-19T14:41:54.207007Z","status":"completed","version":"1.0.0","findings_count":0},{"name":"ai_meta_artifact","ran_at":"2026-05-19T13:33:22.768208Z","status":"skipped","version":"1.0.0","findings_count":0}],"snapshot_sha256":"4d0aea3c360fb49ce2768ee0736721303fc52025ddaac22bb9dc15267a641108"},"references":{"count":52,"sample":[{"doi":"","year":2006,"title":"Agúndez, M. & Cernicharo, J. 2006, ApJ, 650, 374 Agúndez, M., Cernicharo, J., Quintana-Lacaci, G., et al. 2017, A&A, 601, A4 Agúndez, M., Fonfría, J. P., Cernicharo, J., et al. 2012, A&A, 543, A48 Agú","work_id":"eab5b7a3-380e-45dc-9525-ca52839fdeda","ref_index":1,"cited_arxiv_id":"","is_internal_anchor":false},{"doi":"","year":2023,"title":"K., Rastogi, S., & Kumar, B","work_id":"3408ddfa-8a2e-40ea-85bc-562a3f84a6a0","ref_index":2,"cited_arxiv_id":"","is_internal_anchor":false},{"doi":"","year":2021,"title":"Andriantsaralaza, M., Ramstedt, S., Vlemmings, W. H. T., et al. 2021, A&A, 653, A53","work_id":"bbb066b9-9d1f-4a2d-89b6-b7562cba0820","ref_index":3,"cited_arxiv_id":"","is_internal_anchor":false},{"doi":"","year":2022,"title":"Andriantsaralaza, M., Ramstedt, S., Vlemmings, W. H. T., & De Beck, E. 2022, A&A, 667, A74","work_id":"bb3a81a7-7975-4671-869b-eb6c8c7421d8","ref_index":4,"cited_arxiv_id":"","is_internal_anchor":false},{"doi":"","year":2009,"title":"J., & Scott, P","work_id":"7eaee570-e404-4d12-9706-d5d0ec3e5fd6","ref_index":5,"cited_arxiv_id":"","is_internal_anchor":false}],"resolved_work":52,"snapshot_sha256":"4346149f945eb4cbdc9e5bde0dfbfaf8165fd1df76d3adde8214d5e1f35e0371","internal_anchors":0},"formal_canon":{"evidence_count":2,"snapshot_sha256":"5f40012bdd1d9ff433713d960e25dae578d1f812cc61ccdbf6606373a3fa1106"},"author_claims":{"count":0,"strong_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"builder_version":"pith-number-builder-2026-05-17-v1"}