Reports on the Detection of Ethenone in the ISM

Ethenone, H2CCO, aka ketene, had been identified first in spectra recorded toward Sgr B2(OH) by
B. E. Turner,
Microwave Detection of Interstellar Ketene
Astrophys. J. 213, L75–L79 (1977).
The NRAO 11 m telecope was employed to identify three Ka = 1 transitions with J' = 4 and 5. The fourth transition and the two Ka = 0 transitions were detected tentatively around 81 and 101 GHz.

Evidence for the J' = 4, Ka = 0 and 1 transitions were found in Orion A by:
L. E. B. Johansson, C. Andersson, J. Eldér, P. Friberg, Å. Hjalmarson, B. Höglund, W. M. Irvine, H. Olofsson, and G. Rydbeck,
Spectral Scan of Orion A and IRC +10216 from 72 to 91 GHz
Astron. Astrophys. 130, 227–256 (1984).

It is also fairly abundant in dark clouds:
M. Ohishi, K. Kawaguchi, N. Kaifu, W. M. Irvine, Y. C. Minh, S. Yamamoto, S. Saito,
The Ortho to Para Ratio for Ketene in TMC-1
ASP Conf. Ser. 16, 387–391 (1991).

It was also found in three translucent clouds (CB 17 CB 24, and CB 228):
B. E. Turner, R. Terzieva, and E. Herbst,
The Physics and Chemistry of Small Translucent Molecular Clouds. XII. More Complex Species Explainable by Gas-Phase Processes
Astrophys. J. 518, 699–732 (1999).

Contributor(s): H. S. P. Müller; 06, 2006; 03, 2012