2004/10/27 by J. Cernicharo, M. Guelin, J. R. Pardo · 1 citation
Physics and Astronomy · #astro-ph
paper · pdf · doi:10.1086/426439
published as Astrophys.J. 615 (2004) L145-L148 · Preprint of 10 pages
arxiv created 2004/10/27 · arxiv updated 2009/12/01
We report the detection of the linear radical HC4N in the C-rich envelope of IRC+10216. After HCCN, HC4N is the second member of the allenic chain family HC_(2n)N observed in space. The column density of HC4N is found to be 1.5 10**12 cm**(-2). The abundance ratio HC2N/HC4N is 9, a factor of two larger than the decrement observed for the cyanopolyynes HC_(2n+1)N/HC_(2n+3)N. Linear HC4N has a 3-Sigma electronic ground state and is one of the 3 low-energy isomeric forms of this molecule. We have searched for the bent and ringed HC4N isomers, but could only derive an upper limit to their column densities of about 3 10**(12) cm**(-2).