Discovery of CH2CHCCH and detection of HCCN, HC4N, CH3CH2CN, and, tentatively, CH3CH2CCH in TMC-1
Abstract
We present the discovery in TMC-1 of vinyl acetylene, CH2CHCCH, and the detection, for the first time in a cold dark cloud, of HCCN, HC4N, and CH3CH2CN. A tentative detection of CH3CH2CCH is also reported. The column density of vinyl acetylene is (1.2 ± 0.2) × 1013 cm-2, which makes it one of the most abundant closed-shell hydrocarbons detected in TMC-1. Its abundance is only three times lower than that of propylene, CH3CHCH2. The column densities derived for HCCN and HC4N are (4.4 ± 04) × 1011 cm-2 and (3.7 ± 0.4) × 1011 cm-2, respectively. Hence, the HCCN/HC4N abundance ratio is 1.2 ± 0.3. For ethyl cyanide we derive a column density of (1.1 ± 0.3) × 1011 cm-2. These results are compared with a state-of-the-art chemical model of TMC-1, which is able to account for the observed abundances of these molecules through gas-phase chemical routes.
Based on observations carried out with the Yebes 40 m telescope (projects 19A003, 19A010, 20A014, 20D023). The 40 m radio telescope at Yebes Observatory is operated by the Spanish Geographic Institute (IGN, Ministerio de Transportes, Movilidad y Agenda Urbana).- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- March 2021
- DOI:
- 10.1051/0004-6361/202140434
- arXiv:
- arXiv:2102.10920
- Bibcode:
- 2021A&A...647L...2C
- Keywords:
-
- molecular data;
- line: identification;
- ISM: molecules;
- ISM: individual objects: TMC-1;
- astrochemistry;
- Astrophysics - Astrophysics of Galaxies
- E-Print:
- Accepted for publication in A&