Abundances of s-process elements in planetary nebulae: Br, Kr & Xe.

Authors :: Zhang, Y.
Williams, R.
Pellegrini, E.
Cavagnolo, K.
Baldwin, J. A.
Sharpee, B.
Phillips, M.
Liu, X.-W.
Source :: Proceedings of the International Astronomical Union; 04/02/2006, Vol. 2 Issue S234, p549-550, 2p
Publication Year :: 2006
Abstract: We identify emission lines of post-iron peak elements in very high signal-to-noise spectra of a sample of planetary nebulae. Analysis of lines from ions of Kr and Xe reveals enhancements in most of the PNe, in agreement with theories of $s$-process in AGB stars. Surprisingly, we did not detect lines from Br even though $s$-process calculations indicate that it should be produced with Kr at detectable levels. [ABSTRACT FROM PUBLISHER]