Astronomy and Astrophysics – Astrophysics
Scientific paper
Oct 1974
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1974apj...193..335s&link_type=abstract
Astrophysical Journal, vol. 193, Oct. 15, 1974, pt. 1, p. 335-341.
Astronomy and Astrophysics
Astrophysics
93
Abundance, Astronomical Spectroscopy, Galactic Structure, Nebulae, Spiral Galaxies, Astronomical Models, Chemical Composition, Computerized Simulation, Emission Spectra, H Ii Regions, Hydrogen, Nitrogen, Oxygen, Photoionization
Scientific paper
The spectra of H II regions vary systematically across the disks of spiral galaxies. We have used computer models of H II regions to study the changes in line intensities resulting from variations in the chemical abundances, the dust/gas ratio, the clumpiness of the gas, and the effective temperatures of the exciting stars. Our results support Searle's contention that both the N II/O II abundance ratio gradient and the O III abundance/H-beta gradient result from variations in chemical abundances. H II regions in the outermost spiral arms are deficient in nitrogen and oxygen, whereas regions in the innermost arms have nitrogen and oxygen abundances larger than solar. Condensations in the nebulae are required for sufficiently strong O II emission.
No associations
LandOfFree
Composition gradients across spiral galaxies does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Composition gradients across spiral galaxies, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Composition gradients across spiral galaxies will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-791665