{"paper":{"title":"Evolution of N/O Abundance Ratios and Ionization Parameters from z~0 to 2 Investigated by the Direct Temperature Method","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"astro-ph.GA","authors_text":"Kimihiko Nakajima, Masami Ouchi, Takashi Kojima, Takatoshi Shibuya, Yoshiaki Ono, Yuichi Harikane","submitted_at":"2016-05-11T13:35:19Z","abstract_excerpt":"We present N/O abundance ratios, ionization parameters {$q_{\\rm ion}$}, and oxygen abundance O/H for a total of 41 galaxies (11 individual galaxies and a 30-galaxy stack) including {Ly$\\alpha$} emitters and Lyman break galaxies at $z\\sim 2$, and investigate galaxy evolution from $z\\sim 0$ to $2$ in conjunction with 208,529 local SDSS galaxies and 9 green pea galaxies (GPs). In contrast with most of the recent studies, we obtain the N/O ratio, {$q_{\\rm ion}$}, and O/H measurements by direct $T_{\\rm e}$ methods with {[O\\,\\textsc{iii}]} $\\lambda$4363 and {O\\,\\textsc{iii}]} $\\lambda$1665 lines. Ba"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1605.03436","kind":"arxiv","version":3},"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"}