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astro-ph2005
On the Origin of Sulfur
Nils Ryde, David L. Lambert
We present our work on the halo evolution of sulfur, based on observations of the S I lines around 9220 A for ten stars for which the S abundance was obtained previously from much…
astro-ph1998
The nature of the circumstellar CO_2 emission from M giants
N. Ryde, K. Eriksson, B. Gustafsson
The 13-16 um region observed by the Infrared Space Observatory (ISO) of several ABG stars are discussed. We present and analyse spectra of seven M giants which show carbon dioxide…
astro-ph1996
Carbon Stars and Nucleosynthesis in Galaxies
Bengt Gustafsson, Nils Ryde
The role of carbon stars in the build-up of chemical elements in galaxies is discussed on the basis of stellar evolution calculations and estimated stellar yields, abundance analys…