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The radial distribution of molecules in IRC+10216

P. Audinos, C. Kahane, and R. Lucas
Laboratoire d'Astrophysique de l'Observatoire de Grenoble, BP 53 X, 414, rue de la Piscine, 38041 Grenoble cedex, France
IRAM, 300, rue de la Piscine, Domaine Universitaire, 38406 Saint-Martin-d'Hères, France.
Abstract: We present sensitive, high resolution maps of emission in the circumstellar envelope of IRC+10216. We have mapped the J=16-15, J=18-17 and J=24-23 transitions at 1mm and 2mm wavelength. Contrary to previous maps of lower transitions, they show centrally peaked intensity distributions. We resolve this discrepancy by modelling the vibrational and rotational excitation of , showing that it largely results from radiative and collisional excitation in the envelope inner layers. The abundance is changed by this result in the sense that is more abundant than previously thought. Our new results are compared with chemical models.

Robert Lucas
Thu Mar 9 14:24:13 MET 1995