{"paper":{"title":"Infrared [Fe II] emission from P Cygni's nebula: Atomic data, mass, kinematics, and the 1600 A.D. outburst","license":"","headline":"","cross_cats":[],"primary_cat":"astro-ph","authors_text":"Nathan Smith, Patrick Hartigan","submitted_at":"2005-10-31T02:24:15Z","abstract_excerpt":"We present moderate and high-dispersion 1-2.5 micron spectra of the 10 arcsec nebula around P Cygni, dominated by bright emission lines of [Fe II]. Observed [Fe II] line ratios disagree with theoretical transition rates in the literature, so we use the spectrum of P Cygni's nebula to constrain the atomic data for low-lying levels of [Fe II]. Of particular interest is the ratio [Fe II] 12567/16435, often used as a reddening indicator, for which we empirically derive an intrinsic value of 1.49, which is 10--40 per cent higher than previous estimates. High-dispersion spectra of [Fe II] 16435 cons"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"astro-ph/0510836","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":""},"integrity":{"clean":true,"summary":{"advisory":0,"critical":0,"by_detector":{},"informational":0},"endpoint":"/pith/astro-ph/0510836/integrity.json","findings":[],"available":true,"detectors_run":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938"},"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"}