Dust properties around evolved stars from far-infrared size limits
- Texas Univ., Austin (USA) Grenoble Observatoire, Saint-Martin-d'Heres (France) Joint Astronomy Center, Hilo, HI (USA) NASA, Marshall Space Flight Center, Huntsville, AL (USA)
High angular resolution far-infrared scans were obtained of six stars surrounded by circumstellar dust shells believed to result from mass loss by the central star. None of the dust shells was clearly resolved at either 50 or 100 microns; the upper limits are in the range 4 to 10 arcsec. These size limits place constraints on the far-IR dust emissivity and dust density distribution. For one of the objects, AFGL 2343, larger than normal grains are almost certainly required. For several other stars, the size limits are much more consistent with dust having an emissivity law no steeper than 1/lambda in the 1-100-micron spectral region. For IRC + 10216, an earlier suggestion is confirmed that, assuming reasonable grain properties, a smooth radial dust distribution is not consistent with the scans and the energy distribution of the object. 29 refs.
- OSTI ID:
- 5867866
- Journal Information:
- Astrophysical Journal; (USA), Vol. 368; ISSN 0004-637X
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
GENERAL PHYSICS
STARS
COSMIC DUST
FAR INFRARED RADIATION
DENSITY
ENERGY SPECTRA
INFRARED RADIATION
LIMITING VALUES
MASS TRANSFER
RESOLUTION
SPATIAL DISTRIBUTION
STAR EVOLUTION
DISTRIBUTION
DUSTS
ELECTROMAGNETIC RADIATION
PHYSICAL PROPERTIES
RADIATIONS
SPECTRA
640102* - Astrophysics & Cosmology- Stars & Quasi-Stellar
Radio & X-Ray Sources