Crystalline Silicates in Space
نویسندگان
چکیده
منابع مشابه
Photophoresis as a Source of Crystalline Silicates in Comets
Introduction: Crystalline silicates have been detected in a growing number of comets [1] [2] [3]. Since these bodies are presumed to be formed in the cold outer part of the solar nebula, several processes have been invoked in order to explain the origin of their crystalline silicates. It has been suggested that shock waves in the outer solar nebula could anneal the amorphous silicates to crysta...
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Wepresent ISO-SWS spectroscopy of the cool dusty envelopes surrounding two Planetary Nebulae with [WC] central stars, BD+30 3639 and He 2-113. The λ < 15 μm region is dominated by a rising continuumwith prominent emission from C-rich dust (PAHs), while the long wavelength part shows narrow solid state features from crystalline silicates. This demonstrates that the chemical composition of both s...
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We present a new perspective on the crystallinity of dust in protoplanetary disks. The dominant crystallization by thermal annealing happens in the very early phases of disk formation and evolution. Both the disk properties and the level of crystallinity are thereby directly linked to the properties of the molecular cloud core from which the star+disk system was formed. We show that, under the ...
متن کاملThe origin of crystalline silicates in the Herbig Be star HD100546 and in comet Hale-Bopp
We have investigated the spatial distribution, and the properties and chemical composition of the dust orbiting HD100546. This system is remarkably different from other isolated Herbig Ae/Be stars in both the strength of the mid-IR excess and the composition of the circumstellar dust. To explain spectral features and the amount of mid-IR dust emission the presence of a component of small (< 10 ...
متن کاملLetter to the Editor Dust in R71: first detection of crystalline silicates in the LMC
We present infrared spectroscopy taken with the Infrared Space Observatory (ISO) of the Luminous Blue Variable (LBV) R71 in the Large Magellanic Cloud (LMC). The spectrum shows clear evidence for the presence of crystalline olivine at 23.5 μm. This is the first detection of circumstellar crystalline silicates outside our galaxy. In addition, we identify emission at 6.2, 7.7 and possibly 8.6 μm ...
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ژورنال
عنوان ژورنال: Highlights of Astronomy
سال: 2002
ISSN: 1539-2996
DOI: 10.1017/s153929960001279x