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Abundances in Asymmetric PNe: confrontation to AGB models

Abundances in Asymmetric PNe: confrontation to AGB models. Letizia Stanghellini, NOAO Special thanks:

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Abundances in Asymmetric PNe: confrontation to AGB models

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  1. Abundances in Asymmetric PNe: confrontation to AGB models Letizia Stanghellini, NOAO Special thanks: Martin Guerrero, Katia Cunha, Arturo Manchado, Eva Villaver, Bruce Balick, Ting-Hui Lee, Dick Shaw, Pedro Garcia-Lario, Jose Perea-Calderon, Anibal Garcia-Hernandez, James Davies, Amanda Karakas

  2. PNe are probes of stellar evolution • The composition of PNe reflects their progenitors evolutionary paths • Stars that go through the AGB phase may be the principal producers of nitrogen, and supply as much carbon as massive stars • It is essential that any hypothesis of formation of asymmetric PNe takes into account the comparison between PN abundances and evolutionary yields

  3. Selected sample and references • Galactic disk (205 PNe) • Abundances • Stanghellini et al. 06 (homogeneous sample, excludes bulge and halo PNe) • Morphology (R, E, B, BC) • IAC Morphological Catalog, Manchado et al. 96 • Magellanic Clouds (108 LMC and 35 SMC PNe) • Abundances • Leisy & Dennefeld 96; Stanghellini et al. 05, 07 Henry et al. 89; Monk et al. 89; Boroson & Liebert 89; Stasinska et al. 98 • Morphology (R, E, B, BC) • HST database (Shaw et al. 01, 07; Stanghellini et al. 99, 02)

  4. Galactic PNe and AGB models Symmetric PNe Asymmetric PNe Yields from AGB Models    Karakas 1< Mto < 4, Z=0.016    Karakas 4 < Mto < 6.5, Z=0.016    Gavilan 5 < Mto < 8 0.013 < Z < 0.032 (synthetic, extrapolated models)

  5. LMC PNe and AGB models Symmetric PNe Asymmetric PNe Yields from AGB Models    Karakas 1< Mto < 4, Z=0.08    Karakas 4 < Mto < 6.5, Z=0.08

  6. SMC PNe and AGB models Symmetric PNe Asymmetric PNe Yields from AGB Models    Karakas 1< Mto < 4, Z=0.04    Karakas 4 < Mto < 6.5, Z=0.04

  7. Three populations He/H and N/O averages, homogeneous data samples. Bars represent data ranges

  8. Carbon and LMC PNe Symmetric PNe Asymmetric PNe Yields from AGB Models    Karakas 1< Mto< 4, Z=0.008    Karakas 4 < Mto< 5, Z=0.008    Gavilan 5 < Mto< 8 0.013 < Z < 0.032

  9. Spitzer IRS spectra ~40 LMC and SMC PN spectra (GO2); half of the PNe have nebular line-dominated spectra; The other PNe show C-rich dust features (CRD, 90%) or O-rich dust features (ORD, 10%) CRD ORD

  10. Left panels: Triangles: featureless Diamonds: CRD Squares: ORD Right panels: Circles: R Diamonds: E Triangles: BC Squares: B Only symmetric PNe have CRD spectra, and only asymmetric PNe have ORD Spectra Stanghellini et al. 2007, to Appear on ApJ

  11. Left panels: Triangles: featureless Diamonds: CRD Squares: ORD Right panels: Circles: R Diamonds: E Triangles: BC Squares: B

  12. Conclusions • PN observations compared to AGB evolution shows that asymmetric PNe have massive AGB progenitors, lower mass limit depends on metallicity • A small fraction of asymmetric PNe might derive from low-mass binary evolution, where N production is stopped as the members do not suffer third dredge-up • Spitzer spectra show that gas and dust chemistry are compatible with this scenario

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