Bibcode
Stanghellini, Letizia; Garcia-Lario, Pedro; Manchado, A.; Perea, Jose Vicente; Shaw, Richard A.; Villaver, Eva
Referencia bibliográfica
Spitzer Proposal ID #20443
Advertised on:
6
2005
Número de citas
0
Número de citas referidas
0
Descripción
Planetary nebulae (PNe) in the Magellanic Clouds (LMC, SMC) offer a
unique opportunity to study both the population and evolution of low-
and intermediate-mass stars in an environment which is free of the
distance scale bias that hinder Galactic PN studies. At the same time,
LMC and SMC PNe cover a wide metallicity baseline. Their progenitors
might have metallicity from nearly equal to less than a tenth of
Galactic PN progenitors. Such properties make the Magellanic Cloud PNe
the ideal probes to study the effects of progenitor metallicity in the
cosmic recycling. The emission shown by PNe in the 5-40 micron range is
characterized by the presence of a combination of solid state features
(from the dust grains) and nebular emission lines over-imposed on a
strong dust continuum. We propose to acquire low resolution IRS
spectroscopy of a selected sample of LMC and SMC PNe whose morphology,
size, central star brightness, and chemical composition are known. We
propose to: i) determine the dominant chemistry (C-rich vs. O-rich) of
the PN dust through the study of the solid state features, with the
ultimate goal of evaluating the dust formation efficiency versus
metallicity; ii) establish connections between chemistry, morphology,
and evolutionary stage of the PNe; iii) test the current models of
stellar evolution at various initial metallicities, comparing predicted
composition of the dredged-up material and observed composition in the
PNe as a function of the mass of the progenitor star; iv) recover the
AGB mass loss history from the analysis of the overall spectral energy
distribution; v) determine the contribution of the infrared to the total
PN luminosity.