Both sides previous revision Previous revision Next revision | Previous revision Next revisionBoth sides next revision |
molecules:ism:sic2 [2019/10/21 17:35] – mueller | molecules:ism:sic2 [2024/01/23 15:14] – mueller |
---|
===== On the Detection of SiC2 in Circumstellar Envelopes ===== | ===== On the Detection of SiC<sub>2</sub> in Circumstellar Envelopes ===== |
| |
Silacyclopropynylidene, SiC<sub>2</sub>, is a highly unsaturated ring molecule with a <sup>1</sup>//A//<sub>1</sub> ground electronic state. It is highly reactive, but not a radical. Based on a previously reported analysis of the origin band of its //A// – //X// electronic spectrum, 9 unidentified emission features from various observations of the circumstellar envelope (CSE) of the carbon-rich asymptotic giant branch star CW Leo, also known as IRC +10216, were assigned to this molecule by\\ | Silacyclopropynylidene, SiC<sub>2</sub>, is a highly unsaturated ring molecule with a <sup>1</sup>//A//<sub>1</sub> ground electronic state. It is highly reactive, but not a radical. Based on a previously reported analysis of the origin band of its //A// – //X// electronic spectrum, 9 unidentified emission features from various observations of the circumstellar envelope (CSE) of the carbon-rich asymptotic giant branch star CW Leo, also known as IRC +10216, were assigned to this molecule by\\ |
P. Thaddeus, S. E. Cummins, and R. A. Linke,\\ | P. Thaddeus, S. E. Cummins, and R. A. Linke,\\ |
**[[https://ui.adsabs.harvard.edu/abs/1984ApJ...283L..45T|Identification of the SiCC Radical toward IC +10216 – The First Molecular Ring in an Astronomical Source]]**\\ | **[[https://ui.adsabs.harvard.edu/abs/1984ApJ...283L..45T|Identification of the SiCC Radical toward IC +10216 – The First Molecular Ring in an Astronomical Source]]**\\ |
//Astrophys. J.// **283**, L45–L48 (1984). | //Astrophys. J.// **283**, L45–L48 (1984).\\ |
| \\ |
| |
A very large number of SiC<sub>2</sub> emission features to beyond 1100 GHz were observed by\\ | A very large number of SiC<sub>2</sub> emission features to beyond 1100 GHz were observed by\\ |
**[[https://doi.org/10.1016/j.jms.2011.11.006|Spectroscopic Parameters for Silacyclopropynylidene, SiC<sub>2</sub>, from Extensive Astronomical Observations toward CW Leo (IRC +10216) with the //Herschel// Satellite]]**\\ | **[[https://doi.org/10.1016/j.jms.2011.11.006|Spectroscopic Parameters for Silacyclopropynylidene, SiC<sub>2</sub>, from Extensive Astronomical Observations toward CW Leo (IRC +10216) with the //Herschel// Satellite]]**\\ |
//J. Mol. Spectrosc.// **271** (2012) 50 – 55;\\ | //J. Mol. Spectrosc.// **271** (2012) 50 – 55;\\ |
permitting the spectroscopic parameters to be improved considerably. | permitting the spectroscopic parameters to be improved considerably.\\ |
| \\ |
| |
Using the structural and spectroscopic parameters of the main isotopolog, the three //J// = 4 – 3 transitions of <sup>29</sup>SiC<sub>2</sub> and <sup>30</sup>SiC<sub>2</sub> were found soon thereafter in the CSE of CW Leo by\\ | Using the structural and spectroscopic parameters of the main isotopolog, the three //J// = 4 – 3 transitions of <sup>29</sup>SiC<sub>2</sub> and <sup>30</sup>SiC<sub>2</sub> were found soon thereafter in the CSE of CW Leo by\\ |
J. Cernicharo, C. Kahane, J. Gómez-González, and M. Guélin,\\ | J. Cernicharo, C. Kahane, J. Gómez-González, and M. Guélin,\\ |
**[[https://ui.adsabs.harvard.edu/abs/1986A%26A...167L...9C|Detection of <sup>29</sup>SiC<sub>2</sub> and <sup>30</sup>SiC<sub>2</sub> toward IRC +10216]]**\\ | **[[https://ui.adsabs.harvard.edu/abs/1986A%26A...167L...9C|Detection of <sup>29</sup>SiC<sub>2</sub> and <sup>30</sup>SiC<sub>2</sub> toward IRC +10216]]**\\ |
//Astron. Astrophys.// **167**, L9–L12 (1986). | //Astron. Astrophys.// **167**, L9–L12 (1986).\\ |
| \\ |
| |
Even though silacyclopropynylidene has been observed most prominently toward the CSE of CW Leo, it has been detected in the envelopes of other C-rich AGB stars, such as II Lup by\\ | Even though silacyclopropynylidene has been observed most prominently toward the CSE of CW Leo, it has been detected in the envelopes of other C-rich AGB stars, such as II Lup by\\ |
**[[https://ui.adsabs.harvard.edu/abs/1993A%26A...269..377N|A Molecular Radio Line Survey of the Carbon Star IRAS 15194-5115]]**\\ | **[[https://ui.adsabs.harvard.edu/abs/1993A%26A...269..377N|A Molecular Radio Line Survey of the Carbon Star IRAS 15194-5115]]**\\ |
//Astron. Astrophys.// **269**, 377–389 (1993).\\ | //Astron. Astrophys.// **269**, 377–389 (1993).\\ |
Other sources, in which SiC<sub>2</sub> has been detected, are RW LMi (IRC +30219, IRAS 10131+3049, CIT 6), IRAS 15082-4808 (CRL 4211), and LL Peg (CRL 3068, IRAS 23166+1655). | Other sources, in which SiC<sub>2</sub> has been detected, are RW LMi (IRC +30219, IRAS 10131+3049, CIT 6), IRAS 15082-4808 (CRL 4211), and LL Peg (CRL 3068, IRAS 23166+1655).\\ |
| \\ |
| |
P. D. Gensheimer and L. E. Snyder,\\ | P. D. Gensheimer and L. E. Snyder,\\ |
N. A. Patel, K. H. Young, C. A. Gottlieb, P. Thaddeus, R. W. Wilson, K. M. Menten, M. J. Reid, M. C. McCarthy, J. Cernicharo, J. H. He, S. Brünken, D.-V. Trung, and E. Keto,\\ | N. A. Patel, K. H. Young, C. A. Gottlieb, P. Thaddeus, R. W. Wilson, K. M. Menten, M. J. Reid, M. C. McCarthy, J. Cernicharo, J. H. He, S. Brünken, D.-V. Trung, and E. Keto,\\ |
**[[https://doi.org/10.1088/0067-0049/193/1/17|An Interferometric Spectral-line Survey of IRC +10216 in the 345 GHz Band]]**\\ | **[[https://doi.org/10.1088/0067-0049/193/1/17|An Interferometric Spectral-line Survey of IRC +10216 in the 345 GHz Band]]**\\ |
//Astrophys. J. Suppl. Ser.// **193**, Art. No. 17 (2011). | //Astrophys. J. Suppl. Ser.// **193**, Art. No. 17 (2011).\\ |
| \\ |
| |
| |
| |