Emission, absorption and self-absorption in circumstellar dust shells
نویسندگان
چکیده
منابع مشابه
Absorption and emission spectrum
It is well known that main group metal ions with an s* electron configuration form a large variety of polynuclear coordination compounds [l]. Recently it has been suggested that in these compounds a weak metal-metal bonding may exist which is achieved by sp orbital mixing [2]. In particular, calculations on Tl+ clusters were used to support this idea. Unfortunately, the metal-metal interaction ...
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We present a list of post-AGB stars showing molecular line absorption and emission in the optical spectrum. Two objects show CH, one in emission and one in absorption, and ten stars show C2 and CN in absorption. The Doppler velocities of the C2 lines and the rotational temperatures indicate that the line forming region is the AGB remnant. An analysis of the post-AGB stars of which CO millimeter...
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Observations show that 1612MHz masers of OH/IR stars can fade on a timescale of a decade. This fading is probably associated with the switch from rapid mass loss, which is ultimately linked with an internal He-shell flash, to the much slower mass loss supported by more quiescent conditions. We study the observed maser decay with a composite computational model, comprising a time-dependent chemi...
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The lead burdens for children and mothers exposed to lead-contaminated soils and dusts have been investigated in a rural district with minimal atmospheric pollution. A significant relationship was observed between the lead content of blood and hair of children exposed to soils of mean lead content in the range 420-13,969 p.p.m. The blood lead concentration of children was consistently greater t...
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ژورنال
عنوان ژورنال: Monthly Notices of the Royal Astronomical Society
سال: 1981
ISSN: 0035-8711,1365-2966
DOI: 10.1093/mnras/196.4.801