{"paper":{"title":"Full non-LTE multi-level radiative transfer II. The case of a 5-level Ca ii atom with broadened excited levels","license":"http://creativecommons.org/licenses/by-nc-sa/4.0/","headline":"For Ca II H&K and infrared triplet lines in a simplified atmosphere, standard non-LTE with partial redistribution accurately models line formation and makes full non-LTE unnecessary.","cross_cats":[],"primary_cat":"astro-ph.SR","authors_text":"F. Paletou, M. Sampoorna, T. Lagache","submitted_at":"2026-05-13T11:30:55Z","abstract_excerpt":"The so-called full non-local thermodynamic equilibrium (FNLTE) radiative transfer problem allows us to take into account not only deviations of the radiation field from the Planckian but also deviations of the densities and velocity distributions of massive particles from Maxwell-Boltzmann statistics. This article discusses the extension of this formalism to physically realistic multi-level atoms, including natural broadening of the excited levels. In practice, we must solve self-consistently a coupled set of kinetic equations and determine, for each line, an emission and absorption profile by"},"claims":{"count":4,"items":[{"kind":"strongest_claim","text":"Under the conditions studied, for this particular atomic model and for a simplified atmosphere, we find that the standard NLTE with partial redistribution is sufficient to describe the formation of Ca II spectral lines. The more exact treatment of FNLTE is unnecessary in the case of Ca II H & K, and infrared triplet lines, even when accounting for velocity-changing collisions.","source":"verdict.strongest_claim","status":"machine_extracted","claim_id":"C1","attestation":"unclaimed"},{"kind":"weakest_assumption","text":"The assumption that the simplified atmosphere model and the specific physical conditions (including the treatment of velocity-changing collisions) are representative enough to conclude that FNLTE is unnecessary for Ca II lines in general.","source":"verdict.weakest_assumption","status":"machine_extracted","claim_id":"C2","attestation":"unclaimed"},{"kind":"one_line_summary","text":"A new numerical method for full non-LTE multi-level radiative transfer with broadened levels shows that standard NLTE with partial redistribution is sufficient for Ca II spectral lines in the studied simplified case.","source":"verdict.one_line_summary","status":"machine_extracted","claim_id":"C3","attestation":"unclaimed"},{"kind":"headline","text":"For Ca II H&K and infrared triplet lines in a simplified atmosphere, standard non-LTE with partial redistribution accurately models line formation and makes full non-LTE unnecessary.","source":"verdict.pith_extraction.headline","status":"machine_extracted","claim_id":"C4","attestation":"unclaimed"}],"snapshot_sha256":"790525dc1d5a3b395b0389ef6c0d48129a3f5cd53d24035ad195b0f9a18adca9"},"source":{"id":"2605.13374","kind":"arxiv","version":1},"verdict":{"id":"5d9ef72c-f6f3-4537-9222-beedab5aaea0","model_set":{"reader":"grok-4.3"},"created_at":"2026-05-14T18:14:30.598885Z","strongest_claim":"Under the conditions studied, for this particular atomic model and for a simplified atmosphere, we find that the standard NLTE with partial redistribution is sufficient to describe the formation of Ca II spectral lines. The more exact treatment of FNLTE is unnecessary in the case of Ca II H & K, and infrared triplet lines, even when accounting for velocity-changing collisions.","one_line_summary":"A new numerical method for full non-LTE multi-level radiative transfer with broadened levels shows that standard NLTE with partial redistribution is sufficient for Ca II spectral lines in the studied simplified case.","pipeline_version":"pith-pipeline@v0.9.0","weakest_assumption":"The assumption that the simplified atmosphere model and the specific physical conditions (including the treatment of velocity-changing collisions) are representative enough to conclude that FNLTE is unnecessary for Ca II lines in general.","pith_extraction_headline":"For Ca II H&K and infrared triplet lines in a simplified atmosphere, standard non-LTE with partial redistribution accurately models line formation and makes full non-LTE unnecessary."},"references":{"count":39,"sample":[{"doi":"","year":1987,"title":"1987, JQSRT, 38, 427","work_id":"03378b50-d343-4437-9e98-509b4f73d422","ref_index":1,"cited_arxiv_id":"","is_internal_anchor":false},{"doi":"","year":1968,"title":"Avrett, E. H. 1968, in Resonance Lines in Astrophysics, eds. R. G. Athay, J. Mathis, A. Skumanich (Boulder: NCAR), 27","work_id":"5387631c-159e-474d-a755-92d98a09ce6c","ref_index":2,"cited_arxiv_id":"","is_internal_anchor":false},{"doi":"","year":1997,"title":"1997 a , , 328, 706","work_id":"4c88fa59-95ae-4d63-a41a-b7c17badcc72","ref_index":3,"cited_arxiv_id":"","is_internal_anchor":false},{"doi":"","year":1997,"title":"1997 b , , 328, 726","work_id":"cc27b855-b7c0-4d0a-9d88-1f06420d08fd","ref_index":4,"cited_arxiv_id":"","is_internal_anchor":false},{"doi":"","year":1986,"title":"1986, JQSRT, 35, 303","work_id":"d1a45fca-1aef-423e-8046-9fc80db30f9f","ref_index":5,"cited_arxiv_id":"","is_internal_anchor":false}],"resolved_work":39,"snapshot_sha256":"5c2710963d22a6d2455ea77f56f6cbaa72ecaf9693f842f06990f4f8cf703c54","internal_anchors":0},"formal_canon":{"evidence_count":2,"snapshot_sha256":"3b1d44fc5df534e442d9a4cbfa7f14fcd4fb51f9be360bb348a137bc13c0f0a8"},"author_claims":{"count":0,"strong_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"builder_version":"pith-number-builder-2026-05-17-v1"}