Unidentified Species in Envelopes around Carbon Stars
نویسندگان
چکیده
منابع مشابه
The abundance of SiS in circumstellar envelopes around AGB stars
Aims. Given their photospheric origin and refractive nature, SiS molecules can provide important constraints on the relative roles of dust condensation and non-equilibrium processes in regulating the chemistry in circumstellar envelopes around evolved stars. Methods. New SiS multi-transition (sub-)millimetre line observations of a sample of AGB stars with varying photospheric C/Oratios and mass...
متن کاملChemistry in the Envelopes around Massive Young Stars
Recent observational studies of intermediateand high-mass star-forming regions at submillimeter and infrared wavelengths are reviewed, and chemical diagnostics of the different physical components associated with young stellar objects are summarized. Procedures for determining the temperature, density and abundance profiles in the envelopes are outlined. A detailed study of a set of infrared-br...
متن کاملMolecular envelopes around carbon stars Interferometric observations and models of HCN and CN emission
We have observed four carbon stars (W Ori, RW LMi [CIT6], Y CVn, and LP And [IRC+40540]) in the HCN(J = 1 → 0) line and three of them (RW LMi, Y CVn, and LP And) also in the CN(N = 1 → 0) line using the IRAM interferometer on Plateau de Bure. The HCN brightness distributions are centred on the stellar positions suggesting a photospheric origin of this molecule. We see the expected structure of ...
متن کاملCircumstellar emission from dust envelopes around carbon stars showing the silicon carbide feature
Spectroscopic andphotometric data relative to a sample of 55 carbon stars showing the 11.3 μm feature have been fitted in thewavelength range between 0.4 and 100μmbymeans of a radiative transfer model using the laboratory extinction spectra of amorphous carbon and silicon carbide (SiC) grains. The transfer code allows to determine in a self-consistent way the grain equilibrium temperature of th...
متن کاملReaction dynamics of carbon-bearing radicals in circumstellar envelopes of carbon stars.
Crossed molecular beams experiments on dicarbon molecules, C2(X1sigmag+/a3piu), with unsaturated hydrocarbons acetylene (C2H2(X1sigmag+), ethylene (C2H4(X1Ag)), methylacetylene (CH3CCH(X1A1)), and allene (H2CCCH2 (X1A1)) were carried out at 18 collision energies between 10.6 and 50.3 kJ mol(-1) utilizing a universal crossed beams machine to untangle the reaction dynamics forming hydrogen defici...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Proceedings of the International Astronomical Union
سال: 2013
ISSN: 1743-9213,1743-9221
DOI: 10.1017/s1743921313015895