Discovery of five cyano derivatives of propene with the QUIJOTE line survey
J. Cernicharo, R. Fuentetaja, C. Cabezas, M. Agúndez, N. Marcelino, B. Tercero, J. R. Pardo, P. de Vicente
Abstract
We report the discovery of five cyano derivatives of propene towards TMC-1 with the QUIJOTE line survey: trans and cis -crotononitrile ( t -CH 3 CHCHCN, c -CH 3 CHCHCN), methacrylonitrile (CH 2 C(CH 3 )CN), and gauche and cis -allyl cyanide ( g -CH 2 CHCH 2 CN and c -CH 2 CHCH 2 CN). The observed transitions allowed us to derive a common rotational temperature of 7 ± 1 K for all them. The derived column densities are N( t -CH 3 CHCHCN) = (5 ± 0.5) × 10 10 cm −2 , N( c -CH 3 CHCHCN) = (1.3 ± 0.2) × 10 11 cm −2 , N(CH 2 C(CH 3 )CN) = (1.0±0.1) × 10 11 cm −2 , N( g -CH 2 CHCH 2 CN) = (8.0 ± 0.8) × 10 10 cm −2 , and N( c -CH 2 CHCH 2 CN) = (7.0 ± 0.7) × 10 10 cm −2 , respectively. The abundance of cyano-propene relative to that of propene is thus ∼10 −2 , which is considerably lower than those of other cyano derivatives of abundant hydrocarbons. Upper limits are obtained for two ethynyl derivatives of propene ( E and Z -CH 3 CHCHCCH).