Complex interstellar calcium line structure in the Carina nebula.
Abstract
Coude spectrograms of stars in the Carina Nebula are analyzed to determine the cause of an anomalous variation in the interstellar Ca II absorption-line strengths. As many as six components are observed in the spectrum of a single star, the line profiles are found to exhibit large variations over small angular distances, and stars in the outer part of the nebula are found to have single Ca lines, suggesting that the additional components observed in inner-region stars are formed in the inner region. The results are shown to represent a new kind of interstellar-line velocity structure, probably one within or associated with a giant H II region. Observations of the double nebular emission lines and the single He I nebular absorption line are described, and a search for a similar interstellar calcium-line structure at the center of the 30 Doradus nebula in the Large Magellanic Cloud is briefly discussed.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- July 1975
- DOI:
- 10.1086/153720
- Bibcode:
- 1975ApJ...199..535W
- Keywords:
-
- Emission Spectra;
- Interstellar Matter;
- Nebulae;
- Stellar Spectra;
- Absorption Spectra;
- Astronomical Spectroscopy;
- Calcium;
- H Ii Regions;
- Luminous Intensity;
- Magellanic Clouds;
- Oxygen Spectra;
- Spectral Line Width;
- Titanium;
- Astrophysics