{"paper":{"title":"Chemical abundances in M31 from HII regions","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"astro-ph.CO","authors_text":"Almudena Zurita, Fabio Bresolin","submitted_at":"2012-09-07T11:53:29Z","abstract_excerpt":"We have obtained multi-slit spectroscopic observations from 3700A to 9200A with LRIS at the Keck I telescope for 31 HII regions in the disk of the Andromeda galaxy (M31), spanning a range in galactocentric distance from 3.9 kpc to 16.1 kpc. In 9 HII regions we measure one or several auroral lines ([OIII]4363, [NII]5755, [SIII]6312, [OII]7325), from which we determine the electron temperature (Te) of the gas and derive chemical abundances using the 'direct Te-based method'. We analyze, for the first time in M31, abundance trends with galactocentric radius from the 'direct' method, and find that"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1209.1505","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"}