Aperture Effects on Star Formation Rate, Metallicity, and Reddening

• Published in: Publications of the Astronomical Society of the Pacific 2005-03, Vol.117 (829), p.227-244
• Main Authors: Kewley, Lisa J., Jansen, Rolf A., Geller, Margaret J.
• Format: Article
• Language: English
• Subjects: Astronomical extinction; Galaxies; H II regions; Isophotes; Luminosity; Metal abundance; Red shift; Spiral galaxies; Star formation; Visible spectrum
• ISSN: 0004-6280; 1538-3873
• DOI: 10.1086/428303

We use 101 galaxies selected from the Nearby Field Galaxy Survey to investigate the effect of aperture size on the star formation rate, metallicity, and reddening determinations for galaxies. Our sample includes galaxies of all Hubble types except ellipticals with global star formation rates (SFRs) ranging from 0.01 to 100M ⊙yr−1, metallicities in the range \documentclass{aastex} \usepackage{amsbsy} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{bm} \usepackage{mathrsfs} \usepackage{pifont} \usepackage{stmaryrd} \usepackage{textcomp} \usepackage{portland,xspace} \usepackage{amsmath,amsxtra} \usepackage[OT2,OT1]{fontenc} \newcommand\cyr{ \renewcommand\rmdefault{wncyr} \renewcommand\sfdefault{wncyss} \renewcommand\encodingdefault{OT2} \normalfont \selectfont} \DeclareTextFontCommand{\textcyr}{\cyr} \pagestyle{empty} \DeclareMathSizes{10}{9}{7}{6} \begin{document} \landscape $7.9\lesssim \mathrm{log}\,( \mathrm{O}\,/ \mathrm{H}\,) +12\lesssim 9.0$ \end{document} , and reddening of \documentclass{aastex} \usepackage{amsbsy} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{bm} \usepackage{mathrsfs} \usepackage{pifont} \usepackage{stmaryrd} \usepackage{textcomp} \usepackage{portland,xspace} \usepackage{amsmath,amsxtra} \usepackage[OT2,OT1]{fontenc} \newcommand\cyr{ \renewcommand\rmdefault{wncyr} \renewcommand\sfdefault{wncyss} \renewcommand\encodingdefault{OT2} \normalfont \selectfont} \DeclareTextFontCommand{\textcyr}{\cyr} \pagestyle{empty} \DeclareMathSizes{10}{9}{7}{6} \begin{document} \landscape $0\lesssim A( V) \lesssim 3.3$ \end{document} . We compare the SFR, metallicity, and reddening derived from nuclear spectra to those derived from integrated spectra. For apertures capturing