{"paper":{"title":"Testing Narrow-line Seyfert 1 scenarios with photoionization models","license":"","headline":"","cross_cats":[],"primary_cat":"astro-ph","authors_text":"Janek Meerschweinchen (Obernkirchen), Stefanie Komossa (MPE Garching)","submitted_at":"1999-07-27T08:10:20Z","abstract_excerpt":"Narrow Line Seyfert 1 (NLSy1) galaxies have recently received a lot of attention due to their unusual optical--X-ray properties which are not yet well understood. Photoionization models of the circum-nuclear emission/absorption regions allow to investigate scenarios to explain the main characteristics of NLSy1s, i.e., (i) extremely steep X-ray spectra within the ROSAT energy range, (ii) narrow Balmer lines and (iii) weak forbidden lines except for some relatively strong high-ionization iron lines. Here, we focus on (iii). In particular, we study the influence of different EUV - soft-X-ray spec"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"astro-ph/9907373","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"}