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NGC 628 in SIGNALS: Explaining the Abundance-Ionization Correlation in HII Regions

NGC 628 in SIGNALS: Explaining the Abundance-Ionization Correlation in HII Regions

Authors :
Garner III, Ray
Kennicutt Jr, Robert
Rousseau-Nepton, Laurie
Olivier, Grace M.
Fernández-Arenas, David
Robert, Carmelle
Martin, René Pierre
Amram, Philippe
Publication Year :
2024

Abstract

The variations of oxygen abundance and ionization parameter in HII regions are usually thought to be the dominant factors that produced variations seen in observed emission line spectra. However, if and how these two quantities are physically related is hotly debated in the literature. Using emission line data of NGC 628 observed with SITELLE as part of the Star-formation, Ionized Gas, and Nebular Abundances Legacy Survey (SIGNALS), we use a suite of photoionization models to constrain the abundance and ionization parameters for over 1500 HII regions throughout its disk. We measure an anti-correlation between these two properties, consistent with expectations, although with considerable scatter. Secondary trends with dust extinction and star formation rate surface density potentially explain the large scatter observed. We raise concerns throughout regarding various modeling assumptions and their impact on the observed correlations presented in the literature.<br />Comment: 27 pages, 12 figures, 2 tables. Accepted to ApJ

Details

Database :
arXiv
Publication Type :
Report
Accession number :
edsarx.2412.01680
Document Type :
Working Paper