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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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