The double-dust chemistry phenomenon in PNe with [WC]-type central stars

Perea-Calderón, J. V.; García-Hernández, D. A.; Bobrowsky, M.; García-Lario, Pedro
Bibliographical reference

Planetary Nebulae in our Galaxy and Beyond, Proceedings of the International Astronomical Union, Symposium #234. Edited by Michael J. Barlow and Roberto H. Méndez. Cambridge: Cambridge University Press, 2006., pp.483-484

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2006
Number of authors
4
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0
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Description
We present preliminary conclusions derived from the analysis of a sample of galactic PNe with [WC]-type central stars (WCPNe) observed with Spitzer/IRS. We report the detection of double-dust (C-rich and O-rich) chemistry in all stars in the sample for which a good S/N spectrum was obtained. Our observations reveal that the simultaneous presence of oxygen and carbon-rich dust features in the infrared spectra of WCPNe is not restricted to late/cool [WC]-type stars, as previously suggested in the literature, but it is found to be a common feature associated to all WCPNe. In particular, mixed chemistry is observed in at least seven early/hot WCPNe in the sample. Various scenarios are proposed to interpret the results obtained in the framework of the chemical evolution of PNe.