Astron. Astrophys. Suppl. Ser. 130, 1-64

A ¹²CO($J=1\rightarrow 0$) and ($J=2\rightarrow 1$) atlas of circumstellar envelopes of AGB and post-AGB stars

R. Neri¹, C. Kahane², R. Lucas¹, V. Bujarrabal³, and C. Loup⁴

Send offprint request: R. Neri

1 - IRAM, 300 rue de la Piscine, 38406 S$^{\rm t}$ Martin d'Hères, France
2 - Observatoire de Grenoble, BP. 53, 38041 Grenoble Cedex 9, France
3 - Observatorio Astronómico Nacional (I.G.N), Apartado 1143, 28800 Alcalá de Henares, Madrid, Spain
4 - Institut d'Astrophysique de Paris, CNRS, 98 bis Bd. Arago, 75014 Paris, France

Received June 30; accepted October 28, 1997

Abstract:

We present the results of a ¹²CO($J=1\rightarrow 0$) and ($J=2\rightarrow 1$) survey on a sample of 46 objects classified as AGB and post-AGB stars. We have obtained fully sampled high resolution maps of their ¹²CO($J=1\rightarrow 0$) emission by combining visibilities from the IRAM interferometer with short spacing observations from the IRAM 30 m telescope. Properties of their circumstellar envelopes like fluxes, radii, and positions are derived from model fits to the visibilities and compared to the results obtained from ¹²CO($J=2\rightarrow 1$) maps observed at the IRAM 30 m telescope. From the ¹²CO($J=1\rightarrow 0$) observations we have derived mass loss rates for 38 stars and established an empirical relation between the CO photodissociation radius of an envelope and the measured radius in the ($J=1\rightarrow 0$) emission.

Key words: Atlases -- stars: AGB, post-AGB -- stars: circumstellar matter -- stars: mass-loss -- stars: evolution -- radio lines: stars