The interest of high spatial resolution observations of presumed metal-rich H II regions
Abstract
Reasons for large uncertainties in the determination of abundances from the global optical spectra of metal-rich H II regions are examined. Generally, no temperature sensitive line ratio is available in such objects; the effects of temperature gradients inside nebulae may be very severe and it is difficult to correct for temperature gradients on the basis of the available observational data. Finally, even a detailed modeling of a given object leads to uncertain abundances when no direct estimate of an electronic temperature is available, because too little is known of the nebular geometry and exciting conditions. It is suggested that the high abundances suspected for H II regions in inner parts of spiral galaxies could be ascertained, at least in favorable cases, by high-resolution spectral observations.
- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- May 1980
- Bibcode:
- 1980A&A....85..359S
- Keywords:
-
- Abundance;
- H Ii Regions;
- Nebulae;
- Spiral Galaxies;
- High Resolution;
- Oxygen Ions;
- Spectral Resolution;
- Temperature Gradients;
- Astrophysics