Description |
Study of carbon chain molecules in the ISM is of great importance owing to the ubiquity of these molecules and their potential role as the building block of larger molecules or as products of photo-destruction of larger molecules. However the formation mechanism of even the simplest linear carbon chain molecule is still not well understood. The isotopic abundance ratio of C3-13CCC is believed to be an important probe for the chemical routes for the formation of C3, which involve C+. Using HIFI-Herschel C3 has for the first time been detected in the warm envelopes of hot star forming cores (Mookerjea et al. 2010). This has provided access to a much larger column density of C3 than was previously possible with optical and-or mid-infrared studies of C3 in diffuse clouds. The larger column density of C3 implies a higher probability of detecting its rarer isotopologue 13CCC. This detection coupled with the recent success of the Cologne spectroscopy group in identifying the 13CCC molecule in the laboratory and accurate determination of frequencies of several nu2 bending mode ro-vibrational transitions in the far-infrared has set the stage for a search for 13CCC in the interstellar space. We propose to obtain deep integrations of the brightest of the spectral lines for 13CCC towards two very strong continuum sources in both of which C3 has already been clearly seen in absorption. |