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