{"paper":{"title":"The HST Spectrum of I Zw 1: Implications of the C III^* \\lambda 1176 Emission Line","license":"","headline":"","cross_cats":[],"primary_cat":"astro-ph","authors_text":"Ari Laor, Buell T. Jannuzi, Richard F. Green, Todd A. Boroson","submitted_at":"1996-09-24T17:36:09Z","abstract_excerpt":"I Zw 1 is a well known narrow line quasar with very strong Fe II emission. High S/N spectra obtained with the HST FOS show a remarkably rich emission line spectrum. The C III$^* \\lambda 1176$ line is clearly detected in emission for the first time in AGNs. This line arises from radiative decay to the $2s2p^3P^o_{0,1,2}$ metastable levels of C III. The observed flux is  50 larger than expected from collisional excitation, or dielectronic recombination, in photoionized gas. The most plausible mechanism for the large enhancement in the C III^* \\lambda 1176 flux is resonance scattering of continuu"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"astro-ph/9609161","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"}