Extinction of HII regions in the Large Magellanic Cloud
Abstract
The extinction properties of Hii regions in the Large Magellanic Cloud are investigated using radio continuum data obtained from the Molonglo Observatory Synthesis Telescope, digitized and calibrated Hα data and published Balmer decrement measurements. The resulting extinction-colour excess diagram suggests that (1) most Hii regions in the Magellanic Clouds have similar extinction properties to the Galactic ones, (2) all imaginable gas/dust configurations are possible, (3) the extinction of some highly reddened Hii region cores originates externally in cocoon shells. The puzzle of different extinction-colour excess ratios of Galactic and extragalactic Hii regions is explained as being due to the different populations of observed samples rather than any intrinsic differences. The extinction of the observed Galactic Hii regions produced by foreground dust overwhelms the internal extinction, while the situation in the observed extragalactic Hii regions is just the opposite.
- Publication:
-
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- March 1998
- DOI:
- 10.1046/j.1365-8711.1998.01130.x
- Bibcode:
- 1998MNRAS.294..422Y
- Keywords:
-
- Magellanic Clouds;
- H Ii Regions;
- Cosmic Dust;
- Supernova Remnants;
- Radio Spectra;
- Balmer Series;
- Continuous Spectra;
- Milky Way Galaxy;
- H I Regions;
- Radiant Flux Density;
- Astrophysics;
- DUST;
- EXTINCTION;
- HII REGIONS;
- SUPERNOVA REMNANTS;
- MAGELLANIC CLOUDS