Infrared Emission from Dust Structures Surrounding Herbig Ae/Be Stars
Abstract
We present IR observations in J, H, K, L, M, and 8-13-micron bands of Herbig Ae/Be stars located in the Southern Hemisphere. Silicate features detected both in emission and in absorption indicate the presence of dust around these objects. A first analysis based on two-color diagrams, polarization, and luminosity suggests that the spherical geometry for the dust distribution is a more common feature, with respect to the flattened structure. An emission model in which the central object is surrounded by a circumstellar envelope of gas and dust is introduced and the continuum spectrum is computed taking into account radiative properties both of gas (free-free, free-bound, electron scattering) and dust. The numerical results, compared with the observations, suggest that anisotropic dust distributions are not necessarily required to account for the emitting properties of the circumstellar envelopes around Herbig Ae/Be stars.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- October 1992
- DOI:
- 10.1086/171853
- Bibcode:
- 1992ApJ...398..254B
- Keywords:
-
- A Stars;
- B Stars;
- Cosmic Dust;
- Emission Spectra;
- Infrared Radiation;
- Stellar Envelopes;
- Color-Color Diagram;
- Infrared Astronomy Satellite;
- Pre-Main Sequence Stars;
- Southern Sky;
- Stellar Luminosity;
- Stellar Models;
- Stellar Spectra;
- Astrophysics;
- ISM: DUST;
- EXTINCTION;
- STARS: CIRCUMSTELLAR MATTER;
- STARS: FUNDAMENTAL PARAMETERS;
- STARS: PRE--MAIN-SEQUENCE