On the anomaly of the far UV extinction in the 30 Doradus region.
Abstract
Area-integrated ultraviolet observations made with the Netherlands Astronomical Satellite (ANS) of about 800 fields in a 0.7 square degree region around the giant H II region 30 Doradus in the Large Magellanic Cloud are discussed. The five-channel ANS photometric system is shown to be information-redundant in the present application: the LMC observations can be discussed in terms of only two parameters, i.e., the extrapolated visual brightness and a temperature parameter (color). A color-brightness diagram for about 600 fields with good quality measurements is given, and it is concluded that most of the spread in color is caused by differential extinction. By various independent methods it is found that the 2200 A-feature is deficient by a factor of three, on a logarithmic scale, relative to the average galactic extinction law.
- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- March 1978
- Bibcode:
- 1978A&A....64..179K
- Keywords:
-
- Astronomical Photometry;
- Far Ultraviolet Radiation;
- Interstellar Extinction;
- Magellanic Clouds;
- Ultraviolet Photometry;
- Astronomical Netherlands Satellite;
- H Ii Regions;
- Hydrogen Ions;
- Stellar Luminosity;
- Stellar Magnitude;
- Ubv Spectra;
- Ultraviolet Astronomy;
- Astrophysics;
- Extinction:Interstellar Matter;
- H II Regions:Magellanic Clouds