Deviations of Interstellar Extinctions from the Mean R-dependent Extinction Law
Abstract
An analysis is conducted of the deviations from the mean extinction law A(lambda)/A(V) over UV wavelengths emphasizing sightlines through bright nebulosities vs dark clouds. The stellar sample is subdivided into sight lines with defined properties, and different behavior is noted for the deviations in the dark-cloud and bright-nebula sight lines. The deviations are correlated within the same wavenumber interval, but unique shapes for the FUV rise in the deviations are observed. Distributions of silicate grains are considered to account for the extinctions at certain wavenumbers that would explain the observations. The FUV rise in the extinctions is theorized to be related to the UV extinction of polycyclic aromatic hydrocarbons.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- October 1992
- DOI:
- 10.1086/171886
- Bibcode:
- 1992ApJ...398..610M
- Keywords:
-
- Cosmic Dust;
- Interstellar Extinction;
- Interstellar Matter;
- Nebulae;
- Graphite;
- Hydrocarbons;
- Molecular Clouds;
- Silicates;
- Astrophysics;
- ISM: DUST;
- EXTINCTION;
- ULTRAVIOLET: INTERSTELLAR