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J.B. Milingo, R.B.C. Henry (U. of Oklahoma), K.B. Kwitter (Williams College)
Sulfur and argon abundance gradients for the Milky Way are presented based upon newly acquired spectrophotometry of Type II planetary nebulae (PN). These spectra extend from 3600 Å-9600 Åallowing us to use the [SIII] 9069 Åand 9532 Ålines to improve upon earlier sulfur abundance estimates. Considering that a significant portion of sulfur in PN exists in the S(+2) ionization stage, this method should allow us to extrapolate more reliable total element abundances from ionic abundances. Given the progenitor mass and location of Type II PN (close to the Galactic disk), objects in this sample are free of nucleosynthetic self-contamination and thus their S and Ar abundances in particular are expected to reflect levels of these elements in the interstellar medium at the time of PN progenitor formation. Sulfur and argon abundances also provide important information for studying massive star yields of these two elements, as well as their distribution across the Milky Way disk.
The author(s) of this abstract have provided an email address for comments about the abstract: milingo@mail.nhn.ou.edu