Previous | Session 138 | Next
P. J. Huggins (NYU), R. Bachiller, P. Planesas (OAN, Madrid), T. Forveille (CFHT), P. Cox (IAS, Paris)
We report the results of a sensitive survey of young planetary nebulae in the 1.3 mm CO J=2-1 line that significantly increases the available data on dense molecular gas in the early phases of nebula formation. The observations were made with the IRAM 30 m telescope using the 3x3 Heterodyne Receiver Array (HERA). This instrument is effective in discriminating the CO emission of planetary nebulae in the Galactic plane from contaminating emission of interstellar clouds along the line of sight. 110 nebulae were observed in the survey and 40 were detected. The results increase the number of young planetary nebulae with known CO emission by more than a factor of two. The CO spectra reveal a range of line profiles from parabolic to double-peaked, tracing the evolution of structure in the envelopes, and the line widths are found to be significantly wider than on the Asymptotic Giant Branch as a result of the interaction of the envelopes with high velocity jets.
This work is supported in part by NSF AST 03-07277.
Previous | Session 138 | Next
Bulletin of the American Astronomical Society, 36 5
© 2004. The American Astronomical Society.