NOAO >   Observing Info >   Approved Programs >   2002A-0192

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Proposal Information for 2002A-0192


PI: Robert Williams, STScI, wms@stsci.edu
Address: 3700 San Martin Dr., Baltimore, MD 21218, USA

CoI: Jack Baldwin, Michigan State University
CoI: Peter van Hoof, CITA, U. of Toronto
CoI: Brian Sharpee, Michigan State University

Title: Detection of r- and s-Process Elements in Planetary Nebulae

Abstract: We propose to obtain high resolution, very high signal/noise KPNO 4m echelle spectra of two high surface brightness, high ionization planetary nebulae, NGC 7027 and Vy 1-2, to detect very weak s- and r- process emission lines. Previous claims of detection of r-process enhancements, rather unexpected for PNe, were made for NGC 7027 based on low resolution data that suffered substantial line blending. The KPNO 4m echelle will yield far better data for this purpose. We have developed an innovative software-based method of making line identifications that is automatic and reliable, and this will be used with the most recent atomic data for the r- and s-process elements to make secure line ID's. A by-product of this investigation will be detection of lines with fluxes down to ~10^-5 that of H(beta), and our atomic line list and software will provide ID's and intensities for all lines, which has applicability to other problems involving PNe.


National Optical Astronomy Observatory, 950 North Cherry Avenue, P.O. Box 26732, Tucson, Arizona 85726, Phone: (520) 318-8000, Fax: (520) 318-8360



NOAO >   Observing Info >   Approved Programs >   2002A-0192

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