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T. Hasegawa, S. Kwok (Univ. of Calgary)
The 492 GHz fine-structure line of neutral atomic carbon (CI) has been observed in the planetary nebulae (PNs) NGC 6302, IRAS 21282+5050, and NGC 7027, and in the proto-planetary nebula (PPN) AFGL 2688 with the James Clark Maxwell Telescope (JCMT). The CI detections in NGC 6302 and IRAS 21282 are the firsts in these sources, bringing to 5 the number of PNs with detected CI. The estimated CI to CO abundance ratio is higher for a more evolved object, consistent with a trend that the CI to CO ratio increases with the evolution of a post-AGB system from a PPN to a PN. Non-detections are also reported on 11 PPNs and extreme carbon stars. The non-detection sources have CI abundances lower than the level found in the PPN AFGL 2688.
The JCMT is operated by the Joint Astronomy Centre on behalf of the Particle Physics and Astronomy Research Council of the United Kingdom, the Netherlands Organisation for Science Research, and the National Research Council of Canada. This work has utilised archival data at the Canadian Astronomical Data Centre, which is operated by the Herzberg Institute of Astrophysics, National Research Council of Canada. This work is supported by a grant to SK from the Natural Science and Engineering Research Council of Canada and by a Killman Fellowship from the Canada Council for the Arts.
The author(s) of this abstract have provided an email address for comments about the abstract: hasegawa@iras.ucalgary.ca
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Bulletin of the American Astronomical Society, 34, #4
© 2002. The American Astronomical Soceity.