Discovery of methyl silane and confirmation of silyl cyanide in IRC+10216

作者：Cernicharo J^*; Agundez M; Velilla Prieto L; Guelin M; Pardo J R; Kahane C; Marka C; Kramer C; Navarro S; Quintana Lacaci G; Fonfria J P; Marcelino N; Tercero B; Moreno E; Massalkhi S; Santander Garcia M; McCarthy M C; Gottlieb C A; Alonso J L

来源：Astronomy & Astrophysics, 2017, 606: L5.

DOI：10.1051/0004-6361/201731672

• stars: individual: IRC+10216
• stars: carbon
• astrochemistry
• stars: AGB and post-AGB

We report the discovery in space of methyl silane, CH3SiH3, from observations of ten rotational transitions between 80 and 350 GHz (J(u) from 4 to 16) with the IRAM 30 m radio telescope. The molecule was observed in the envelope of the C-star IRC + 10216. The observed profiles and our models for the expected emission of methyl silane suggest that the it is formed in the inner zones of the circumstellar envelope, 1-40 R-*, with an abundance of (0.5-1) x 10(-8) relative to H-2. We also observed several rotational transitions of silyl cyanide (SiH3CN), confirming its presence in IRC + 10216 in particular, and in space in general. Our models indicate that silyl cyanide is also formed in the inner regions of the envelope, around 20 R-*, with an abundance relative to H-2 of 6 x 10(10). The possible formation mechanisms of both species are discussed. We also searched for related chemical species but only upper limits could be obtained.

• 出版日期2017-10-9