The Astrophysical Journal · 1971 · 337 citations · 0 references
Natural SciencesAstronomyPhysicsAstrophysicsExtragalactic AstronomyStellar AstronomyGalactic DiskH Ii RegionsStellar PopulationsAbundance ChangesChemical Abundance GradientsCompact H Ii RegionsGalaxy DisksSpiral Arms In DisksStellar Population Gradients
The integrated spectra of H ii regions located in the inner spiral arms of Sc galaxies are systematically different from those of H ii regions in the outer arms. This is, in part at least, an abundance effect. The N/O ratio (and probably also the abundance ratios 0/H and N/H) decreases from the inner to the outer arms.