NOAO > Observing Info > Approved Programs > 2009B-0053
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NOAO > Observing Info > Approved Programs > 2009B-0053 |
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PI: Karen Kwitter, Williams College, kkwitter@williams.edu
Address: Astronomy Department, 33 Lab Campus Drive, Williamstown, MA 01267, USA
CoI: Bruce Balick, University of Washington
CoI: Richard C. Henry, University of Oklahoma
CoI: Letizia Stanghellini, NOAO
Title: The Light Metals in the Oldest PN Population of M31
Abstract:
Our ultimate goal is to illuminate the origins of the ``light
metals'' in the ancient halos of spiral galaxies like ours. We propose
here to measure emission line fluxes in the blue in nine planetary
nebulae (PNe) in the halo/thick disk of M31. We will combine this data
with red spectral data already in hand to determine the abundances of
light metals (N, O, Ne, [C via HST], and possibly S) in these PNe, which
represent the ISM from which the oldest surviving stars in M31 formed.
The progenitors of these PNe formed from the ``second ISM'': a medium
enriched only by the earliest supernovae. Determining the provenance of
the material that formed the progenitors of currently-observable PNe in
M31 is an important step toward understanding the process of galaxy
development and the early production of the light metals. Our results
will be compared with published results of [Fe/H] in red giants in the
same stellar population and compared to light metal abundances in far
younger PNe observed in M31 and the Milky Way.
National Optical Astronomy Observatory, 950 North Cherry Avenue, P.O. Box 26732, Tucson, Arizona 85726, Phone: (520) 318-8000, Fax: (520) 318-8360
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NOAO > Observing Info > Approved Programs > 2009B-0053 |
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