{"paper":{"title":"A quantitative NLTE analysis of visual and ultraviolet spectra of four helium-rich subdwarf O stars","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"astro-ph.SR","authors_text":"Andreas Irrgang, Marcello Miller Bertolami, Marilyn Latour, Markus Schindewolf, Peter Nemeth, Tiara Battich, Ulrich Heber","submitted_at":"2018-10-18T14:34:42Z","abstract_excerpt":"Hot subdwarfs represent a poorly understood late phase of stellar evolution. While binary evolution plays an important role for B-subdwarfs (sdB), the origin of the He dominated O-subdwarfs (He-sdO) is unknown. We search for chemical signatures of their genesis by means of quantitative analyses of visual and FUV spectra. Using Tlusty/Synspec to compute line blanketed NLTE model atmospheres, Teff/log g and abundances have been derived for 4 prototypical He-sdO stars. Final models included H,He,C,N,O,Ne,Mg,Al,Si,P,S,Fe&Ni. Because of the enrichment of either N or C, models including these elemen"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1810.08082","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"}