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		| Paper: | 
		Nitrogen and Oxygen Abundances in Outlying H II Regions of Spiral Galaxies | 
	 
	
		| Volume: | 
		147, Abundance Profiles: Diagnostic Tools for Galaxy History | 
	 
	
		| Page: | 
		98 | 
	 
	
		| Authors: | 
		van Zee, Liese | 
	 
	
	
		| Abstract: | 
		The results of nitrogen and oxygen abundance measurements for 180 spiral galaxy H ii regions are presented. In high metallicity H ii regions, the nitrogen-to-oxygen ratio increases linearly with the oxygen abundance, as expected for secondary nitrogen production. However, for abundances less than 1/3 solar (12 + \log(O/H) < 8.45), the nitrogen-to-oxygen ratio plateaus in both spiral and dwarf galaxy H ii regions. This suggests that nitrogen has both a primary and secondary component at low metallicities in all types of galaxies. | 
	 
	
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