Discovery of linear propadienone
Year: 2025
Type: article
Abstract: We report the first detection in space of propadienone, the linear isomer (l-H 2 C 3 O) of cyclopropenone (c-H 2 C 3 O). We also report the first detection of the isotopologues c-H 2 13 CCCO and c-HDCCCO of c-H 2 C 3 O. The astronomical observations are part of QUIJOTE, a line survey of TMC-1 in the frequency range 31.0–50.3 GHz, complemented with data between 71.6–116.0 GHz, and carried out with Yebes-40 m and IRAM-30 m telescopes, respectively. We obtain a total column density of 3.7 × 10 10 cm −2 for l-H 2 C 3 O at an excitation temperature of 4.8 K. We find that the isomer is about eight times less abundant than the cyclic one. We also report a detailed line-byline study of cyclopropenethione (c-H 2 C 3 S) to compare the abundance of the O and S isomers. We find that cyclic O-isomers are more abundant than cyclic S-isomers; however, the opposite trend is found for the most stable linear isomers, with l-H 2 C 3 S being more than one order of magnitude more abundant than l-H 2 C 3 O. A comprehensive theoretical chemical analysis shows that the abundances of the H 2 C 3 O and H 2 C 3 S isomers are controlled by different formation pathways. In particular, while l-H 2 C 3 O is potentially produced by dissociative electron recombination reactions, ion-neutral chemistry is more effective at producing l-H 2 C 3 S and c-H 2 C 3 S.
Source: Astronomy and Astrophysics
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $1,865
Awards: The trail of sulphur: from molecular clouds to life, G121809054, G1397962376, G1855990336, G2190061679, G2262748287, G2660406951, G3443738222, G3480869486, G3518538256, G3681454997, G4042783231, G425668148, G4442677895, G4526231891, G464105488, G5184147302, G5421974903, G5572486069, G582065459, G6218905885, G7084143925, G7312425167, G8920660035
OpenAlex ID: W4416583764