molecules:ism:sic [CDMS classic documentation]

This page is read only. You can view the source, but not change it. Ask your administrator if you think this is wrong.

===== On the Detection of Circumstellar Silicon Carbide, SiC =====

Silicon carbide, SiC, has an inverted <sup>3</sup>Π ground electronic state. The low-lying Ω = 2 component shows negligible Λ-doubling. The Ω = 1 and 0 components are about 60 amd 120 K higher in energy, respectively, and show substantial Λ-doubling.\\
SiC has been detected thus far only in the circumstellar envelope of CW Leo, also known as IRC +10216. 3, 3, and 1 components were detected for the //J"// = 1, 3, and 5 transitions near 80, 160, and 240 GHz covering all fine structure components by\\
J. Cernicharo, C. A. Gottlieb, M. Guélin, P. Thaddeus, and J. M. Vrtílek,\\
**[[https://ui.adsabs.harvard.edu/abs/1989ApJ...341L..25C|Astonomical and Laboratory Detection of the SiC Radical]]**\\
//Astrophys. J.// **341**, L25–L28 (1989).\\
The molecule occurs further away from the star than SiS or SiC<sub>2</sub> as judged by the line shape. The excitation is probably far from LTE as the transitions within each fine structure component indicate a rotational temperature of around 13 K. In contrast, the relative intensities of the fine structure transitions suggest a temperature closer to 90 K.


----

Contributor(s): H. S. P. Müller; 09, 2012


----