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

We present the results of a (CO)-C-12 (J = 1 --> 0) and (J = 2 --> 1) survey on a sample of 46 objects classified as AGE and post-AGE stars. We have obtained fully sampled high resolution maps of their (CO)-C-12 (J = 1 --> 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 (CO)-C-12 (J = 2 --> 1) maps observed at the IRAM 30 m telescope. From the (CO)-C-12 (J = 1 --> 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 --> 0) emission.