2016/12/12 by David C. Nicholls, Ralph S. Sutherland, Michael A. Dopita +4 · 2 citations
Physics and Astronomy · #Abundance (ecology) #Astronomy #Astrophysics #Astrophysics and Star Formation Studies #Ecology #Galaxy #Galaxy formation and evolution #Gamma-ray bursts and supernovae #Metallicity #Milky Way #Physics #Redshift #Scaling #Stars #Stellar, planetary, and galactic studies #astro-ph.GA
paper · pdf · doi:10.1093/mnras/stw3235
43 pages, 13 figures, 5 tables. Accepted for publication in MNRAS
arxiv created 2016/12/12 · openalex publication_date 2016/12/12 · arxiv updated 2017/04/12 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We present a new basis for scaling abundances with total metallicity in nebular photoionization models, based on extensive Milky Way stellar abundance data, to replace the uniform scaling normally used in the analysis of H II regions. Our goal is to provide a single scaling method and local abundance reference standard for use in nebular modelling and its key inputs, the stellar atmosphere and evolutionary track models. We introduce a parametric enrichment factor, ζ, to describe how atomic abundances scale with total abundance, which allows for a simple conversion between scales based on different reference elements (usually oxygen or iron). The models and parametric description provide a more physically realistic approach than simple uniform abundance scaling. With appropriate parameters, the methods described here may be applied to H II regions in the Milky Way, large and dwarf galaxies in the local Universe, active galactic nuclei, and to star-forming regions at high redshift.