Abundances in extragalactic H II regions
Abstract
Giant H II regions can be observed out to large distances. They trace recent star formation and, through the analysis of their chemical composition, previous star formation activity. Systematic effects such as metallicity gradients across the disks of spirals and the correlation of metallicity with total galaxy mass offer important constraints on galaxy evolution. The helium abundance in regions where the gas has experienced little stellar nuclear processing provides an important test of cosmological theories. Some of the current uncertainties in interpreting nebular spectra are likely to be resolved by the next generation of ground-based, airborne, and spaceborne telescopes.
- Publication:
-
The Interstellar Medium in Galaxies
- Pub Date:
- 1990
- DOI:
- 10.1007/978-94-009-0595-5_10
- Bibcode:
- 1990ASSL..161..257D
- Keywords:
-
- Abundance;
- H Ii Regions;
- Intergalactic Media;
- Star Formation;
- Astronomical Models;
- Chemical Composition;
- Dwarf Galaxies;
- Interstellar Gas;
- Metallicity;
- Nebulae;
- Astrophysics