abundances in asymmetric pne: confrontation to agb models
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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
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
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)
MW Disk LMC SMC
He/H symmetric (R, E) asymm. (B, BC)
0.12 0.11 0.15
0.100.090.10
0.0910.0860.092
C/H [104] symmetric (R, E) asymm. (B, BC)
5.7-
-
-
3.35.22.0
2.83.3-
N/H [104] symmetric (R, E) asymm. (B, BC) bipolars (B)
2.41.64.66.0
0.970.671.52.3
0.460.300.65-
O/H [104] symmetric (R, E) asymm. (B, BC)
3.5 3.4 3.8
1.92.02.1
1.11.50.80
N/O symmetric (R, E) asymm. (B, BC) bipolars
0.66 0.42 1.321.63
0.620.360.931.4
0.600.160.91-
Galactic PNe and AGB models
Symmetric PNeAsymmetric PNe
Yields from AGB Models Karakas 1< Mto < 4, Z=0.016 Karakas 4 < M� � � to < 6.5, Z=0.016 Gavilan 5 < Mto < 80.013 < Z < 0.032 (synthetic, extrapolated models)
LMC PNe and AGB models
Symmetric PNeAsymmetric PNe
Yields from AGB Models Karakas 1< Mto < 4, Z=0.08 Karakas 4 < M� � � to < 6.5, Z=0.08
SMC PNe and AGB models
Symmetric PNeAsymmetric PNe
Yields from AGB Models Karakas 1< Mto < 4, Z=0.04 Karakas 4 < M� � � to < 6.5, Z=0.04
Three populationsHe/H and N/O averages, homogeneous data samples. Bars represent data ranges
Symmetric PNeAsymmetric PNe
Yields from AGB Models Karakas 1< Mto < 4, Z=0.008 Karakas 4 < M� � � to < 5, Z=0.008 Gavilan 5 < Mto< 80.013 < Z < 0.032
Carbon and LMC PNe
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
Left panels:Triangles: featurelessDiamonds: CRDSquares: ORD
Right panels:Circles: RDiamonds: ETriangles: BCSquares: B
Only symmetric PNe have CRD spectra, and onlyasymmetric PNe have ORD Spectra
Stanghellini et al. 2007, to Appear on ApJ
Left panels:Triangles: featurelessDiamonds: CRDSquares: ORD
Right panels:Circles: RDiamonds: ETriangles: BCSquares: B
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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