A theoretical study of circumstellar dust around Ae/Be stars

Thesis/Dissertation · Sun Jan 01 04:00:00 EST 1989

OSTI ID:6742067

Sorrell, W H

Numerical radiative transfer models are used to discuss the properties of circumstellar dust grains around Ae/Be stars showing strong infrared excess emission. It is assumed that the dust grains consist of a silicate-graphite mixture distributed in a spherical shell around the stars. It is further assumed that a black body spectrum is a useful approximation to the continuous energy distribution of the redden star. The stars selected for study are six Herbig Ae/Be stars, five peculiar shell stars, and the central object in the Red Rectangle Nebula. Observed flux data over the wavelength bands 1200A to 100 microns are assembled from the various sources in the literature. Such data make possible to carry out a multi-wavelength study from the far-UV to the far-IR. In addition to modeling the continuum energy distribution, special attention is given to fitting observed dust spectroscopic features with corresponding features expected from model silicate and graphite grains. By comparing model absorption curves and energy distributions to observations, it is then possible to strengthen constraints on dust-grain composition, abundance, and grain size distributions.

• Research Organization: Wisconsin Univ., Madison, WI (USA)
• OSTI ID: 6742067
• Country of Publication: United States
• Language: English

Related Subjects

640102* -- Astrophysics & Cosmology-- Stars & Quasi-Stellar
Radio & X-Ray Sources
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ATMOSPHERES
CARBON
COSMIC DUST
CRYSTAL STRUCTURE
DATA
DUSTS
ELECTROMAGNETIC RADIATION
ELECTRON TRANSFER
ELEMENTAL MINERALS
ELEMENTS
ENERGY SPECTRA
FAR INFRARED RADIATION
GRAIN SIZE
GRAPHITE
INFORMATION
INFRARED RADIATION
MATHEMATICAL MODELS
MICROSTRUCTURE
MINERALS
MOBILITY
NONMETALS
NUMERICAL DATA
OXYGEN COMPOUNDS
PARTICLE MOBILITY
PARTICLE SIZE
RADIATIONS
SILICATES
SILICON COMPOUNDS
SIZE
SPECTRA
STARS
STELLAR ATMOSPHERES
THEORETICAL DATA