Radio Search for H2CCC toward HD 183143 as a Candidate for a Diffuse Interstellar Band Carrier
Abstract
To clarify the authenticity of a recently proposed identification of H2CCC (linear-C3H2) as a diffuse interstellar band (DIB) carrier, we searched for the rotational transition of H2CCC at a frequency of 103 GHz toward HD 183143 using the 45 m telescope at the Nobeyama Radio Observatory. Although rms noise levels of 32 mK in the antenna temperature were achieved, detection of H2CCC was unsuccessful, producing a 3σ upper limit corresponding to a column density of 2.0 × 1013 cm-2. The upper limit indicates that the contribution of H2CCC to the DIB at 5450 Å is less than 1/25; thus, it is unlikely that the laboratory bands of the B 1 B 1-X 1 A 1 transition of H2CCC and the DIBs at 5450 Å (and also 4881 Å) toward HD 183143 are related.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- July 2012
- DOI:
- 10.1088/2041-8205/753/1/L11
- arXiv:
- arXiv:1206.1980
- Bibcode:
- 2012ApJ...753L..11A
- Keywords:
-
- astrochemistry;
- ISM: clouds;
- ISM: molecules;
- radio lines: ISM;
- Astrophysics - Solar and Stellar Astrophysics
- E-Print:
- Astrophysical Journal Letters, accepted