hydrodynamical interpretation of basic nebular structures m. steffen & d. schönberner m....
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Hydrodynamical Interpretation Hydrodynamical Interpretation of Basic Nebular Structuresof Basic Nebular Structures
M. Steffen &M. Steffen &
D. D. SchönbernerSchönberner
M. Steffen &M. Steffen &
D. D. SchönbernerSchönberner
Abell 39 (WIYN)
Astrophysikalisches Institut Astrophysikalisches Institut Potsdam, GermanyPotsdam, Germany
Hydrodynamical Interpretation Hydrodynamical Interpretation of Basic Nebular Structuresof Basic Nebular Structures
Introduction: observed structures
PN physics and hydrodynamical modeling
Results from state-of-the-art simulations typical time evolution of PN structures dependence on mass loss of AGB progenitor
Conclusions and outlook
M. Steffen & D. SchönbernerM. Steffen & D. SchönbernerAstrophysikalisches Institut Potsdam, GermanyAstrophysikalisches Institut Potsdam, Germany
Observed PN structures: An overview
Examples of Examples of young young Planetary Nebulae Planetary Nebulae
Teff 36 000 K
He 2-131
Teff 30 000 K
IC 418
Sharp ionization front, optically thick in Ly-continuum
HST H Image HST H Image
Examples of Examples of middle-aged middle-aged Planetary Nebulae Planetary Nebulae
Teff 50 000 K
NGC 6826
Teff 50 000 K
IC 3568
Typical double-shell PNe, optically thin in Ly-continuum
HST color composite
HST V image
Rim RimShell
Shell
Halo
NGC 6826, observed with PMAS A&G camera (© 2004, M. Roth)
OIII, shortOIII, short
AGB HaloAGB Halo
OIII, long
Example of an AGB halo: Example of an AGB halo: NGC 6826NGC 6826
Examples of Examples of middle-agedmiddle-aged Planetary Nebulae Planetary Nebulae
Teff 100 000 K
NGC 2022NGC 2022
Teff 75 000 K
NGC 3242NGC 3242
Typical double-shell PNe, optically thin in Ly-continuum
HST V imageHST V imageHST V imageHST V image
Rim
RimShell
Shell
Halo
Xrays
NGC 2022 [OIII] images obtained with NTT/EMMI (Corradi et al. 2003)
Example of an AGB halo: Example of an AGB halo: NGC 2022NGC 2022
Examples of Examples of old old Planetary Nebulae Planetary Nebulae
Teff 117 000 K
Abell 39Abell 39
Single-shell PN, fully ionized
WIYN [OIII] imageWIYN [OIII] image
Rimno Shell
NGC 3587NGC 3587 KPNO 0.9mKPNO 0.9m
Double-shell PN, but no bright rimpartially ionized, complex morphology
Teff 110 000 K
Example of an Example of an oldold Planetary Nebulae Planetary Nebulae
Teff 114 000 KL 500 L
NGC 2438NGC 2438
Triple-shell configuration, partially recombined 2nd shell ?
Bright ´core´
Brighthalo
NTT H+[NII] NGC 2438NGC 2438 NTT H+[NII]
Bright´core´
Fainthalo
(Data from Corradi et al. 2000)
Sharply boundedSharply boundeddiffuse X-ray emission diffuse X-ray emission from central cavityfrom central cavity
©© M. Guerrero 2005 M. Guerrero 2005
HST [N II]HST HXMM X-rays
central star(no X-ray source)
Central CavityShell
Rim
X-ray detection of hot gas in PNeX-ray detection of hot gas in PNe
NGC 3242
Origin and evolution of Origin and evolution of observed structures ?observed structures ?Origin and evolution of Origin and evolution of observed structures ?observed structures ?
Theoretical concepts Theoretical concepts and models includingand models includingthe essential physics !the essential physics !
Theoretical concepts Theoretical concepts and models includingand models includingthe essential physics !the essential physics !
Hydrodynamical modeling of Planetary Nebulae
Hydrodynamical modeling of Planetary Nebulae
AGB & post-AGB stellar evolution with mass loss Teff (t), L (t), M(t), Vwind (t)
Non-equilibrium physics of a low-density plasma time-dependent ionization / recombination
energy balance due to radiative heating / cooling
Radiation hydrodynamics of stellar winds Dust-driven outflows (AGB) Wind -wind interaction (PPN, PN)
Essential physical ingredients:Essential physical ingredients:
•
1D Rotation, magnetic fields, binarity 2D, 3D
Pot
sdam
NE
BE
L M
odel
s
Example of complex structures: Example of complex structures: NGC 6543NGC 6543
HST color composite
Rotation, magnetic fields, binarity ?
AGB wind modelAGB wind model
Input:Input:MMiniini, , i i stellar evolutionM*(t), L*(t), T*(t), M*(t)Dust propertiesTc, a, I, Qabs(), Qsca()d/ g
ISM
zone
dust-free
5 1014 cm
Slow AGB windV 10 .. 15 km/s
gas & dustgas & dust
•
Output:Output:Wind structure & evolutionr1(t), Vg(r,t), Vd(r,t),g(r,t), d(r,t), Td(r,t)Maps I(x,t,)SEDs F(,t)
The final 350 000 years on the AGBThe final 350 000 years on the AGB
Stellar evolution + two-component hydrodynamics:Stellar evolution + two-component hydrodynamics:
( M( Mii = 3 M = 3 M M Mff = 0.605 M = 0.605 M ))Stellar evolution: Stellar evolution: Blöcker 1995Blöcker 1995
Steffen et al. 1998 / 2005
Dust: Dust: astronomical silicatesastronomical silicates (r) ~ r-, 3V(r) 10 .. 15 km/s
(r) ~ r-, 3V(r) 10 .. 15 km/s
The first 3 000 years of post-AGB evolutionThe first 3 000 years of post-AGB evolution
M=0.595 M
Snapshot: IC 418Snapshot: IC 418
M=0.595 M
Comparison of observation and model: IC 418Comparison of observation and model: IC 418
IC 418
HST H Image
Sharp outer edge of shell: D-type ionization frontFuture rim very faint:wind interaction still weak
Surface brightness profiles:
d [arcsec]
Proto rim
Proto rim
Observed and synthetic line profiles: IC 418Observed and synthetic line profiles: IC 418Central line profiles indicate positive velocity gradient:
2 x 15 km/s2 x 15 km/s
Model nebula (Teff=36300 K, optically thick)Observation © 2003 R. Corradi
[O III] [O III]
[N II][N II]
The formation of a double-shell nebulaThe formation of a double-shell nebula
M=0.595 M
Snapshot: NGC 6826Snapshot: NGC 6826
Rim
Rim
Shell Shell
M=0.595 M
Halo Halo
Observed and modeled surface brightness profiles(Schönberner, Jacob & Steffen, 2005)(Schönberner, Jacob & Steffen, 2005)
Observed and modeled surface brightness profiles(Schönberner, Jacob & Steffen, 2005)(Schönberner, Jacob & Steffen, 2005)
NGC 6826 – [O III] IC 2448 – [O III] NGC 3242 – [O III] NGC 3242 – He II
Observed and synthetic surface brightness distributions
NGC 6826 H NGC 3242 H NGC 1535 H
Comparison of observation and model: NGC 3242Comparison of observation and model: NGC 3242
Stellar evolution + radiation hydrodynamics:
Stellar evolution + radiation hydrodynamics:CCD images (Balick 1987):CCD images (Balick 1987):
H H [O III][O III]
[N II] [N II][He II] [He II]
Observed and synthetic line profiles: NGC 6826Observed and synthetic line profiles: NGC 6826
Rim and shell expand independently (different driving mechanisms)
Model nebula (Teff=67 800 K)Chu et al. 1984(Data © 1999 Lehmann/Hildebrandt)
[O III] [O III]
2 x 8 km/s
Rim
2 x 24 km/sShell
Vrim ~ strength of central star wind & ambient density ( MAGB )
Vshell ~ density gradient of ambient AGB wind & sound speed
Observed expansion velocities of double-shell PNe(Schönberner et al. 2005)(Schönberner et al. 2005)
Observed expansion velocities of double-shell PNe(Schönberner et al. 2005)(Schönberner et al. 2005)
Doppler velocities from Gaussian decomposition
Expansion velocitiesincrease with evolution
Vshell > Vrim
Expansion velocities and kinematic ages of double-shell Planetary Nebulae
(Schönberner, Jacob & Steffen 2005)(Schönberner, Jacob & Steffen 2005)
Expansion velocities and kinematic ages of double-shell Planetary Nebulae
(Schönberner, Jacob & Steffen 2005)(Schönberner, Jacob & Steffen 2005)
Rim Shell
True age [1000 yr] True age [1000 yr]Kin
emat
ic a
ge [
1000
yr]
Kin
emat
ic a
ge [
1000
yr]
Rim Doppler velocity: roughly constant kinematic age useless
Shell Doppler velocity: kinematic age real age [N II] preferred method
The phase of partial recombinationThe phase of partial recombination
M=0.605 M
Snapshot: NGC 2438Snapshot: NGC 2438
Rim
Rim
Shell Shell
M=0.605 M
Observation and model: NGC 2438Observation and model: NGC 2438
NTT image, Corradi et al. 2000
H+[N II]
Bright core = RimInner halo = Recombined shell
H+[N II]
Outer halo = Fossil AGB wind
Hydrodynamical interpretation:
PN evolution of low mass CS: no recombination phasePN evolution of low mass CS: no recombination phase
M=0.565 M
Snapshot: Abell 39Snapshot: Abell 39
M=0.565 M
Observation and model: Abell 39Observation and model: Abell 39
Shell swallowed by rim
Surface brightness profiles:
Observed E-W [O III] slice (Jacoby et al. 2001)
Hydrodynamical model, M=0.565 M (Perinotto et al. 2004)
relic of shell
PN evolution of massive CS: trapped ionizationPN evolution of massive CS: trapped ionization
M=0.696 M
Snapshot: NGC 7027Snapshot: NGC 7027
M=0.696 M
rim
shell
Comparison of observation and model: NGC 7027Comparison of observation and model: NGC 7027
Optically thick rim/shell structure
Diffuse outer edge of shell: D-type ionization front beginning recombination
Surface brightness profiles:
Teff 200 000 K, L 8000 L
HST NICMOS IR image
Schönberner, Jacob, Steffen 2005
rim
shell
Does the AGB mass loss history Does the AGB mass loss history influence the PN evolution ?influence the PN evolution ?
Does the AGB mass loss history Does the AGB mass loss history influence the PN evolution ?influence the PN evolution ?
Structure and expansion properties of Structure and expansion properties of Planetary Nebulae provide constraintsPlanetary Nebulae provide constraintson the final phases of AGB mass loss on the final phases of AGB mass loss
Structure and expansion properties of Structure and expansion properties of Planetary Nebulae provide constraintsPlanetary Nebulae provide constraintson the final phases of AGB mass loss on the final phases of AGB mass loss
Yes !Yes !Yes !Yes !
Influence of AGB mass loss on PN structureInfluence of AGB mass loss on PN structure
Simple initial model (r) ~ r-2
Simple initial model (r) ~ r-2
H surface brightness
Rim
Shell
Halo
AGB Hydro simulation(r) ~ r-, 3
AGB Hydro simulation(r) ~ r-, 3
H surface brightness
RimShell
Halo
Circumstellar environment and expansion properties of Planetary Nebulae (Schönberner et al. 2005)(Schönberner et al. 2005)
Circumstellar environment and expansion properties of Planetary Nebulae (Schönberner et al. 2005)(Schönberner et al. 2005)
Shell expansion velocity depends only on slope of AGB wind density (and cs)(cf. Chevalier 1997, Shu et al. 2002)
Shell expansion velocity depends only on slope of AGB wind density (and cs)(cf. Chevalier 1997, Shu et al. 2002)
Initial AGB wind density:
r-
2.5 < < 3.3
Typical double-shell PNe:25 km/s < Vshell < 40 km/s
(Vsh
ell-V
AG
B)
/ cs
The halo of NGC 6826The halo of NGC 6826
Inner halo: I ~ r –, 5 .. 7
Outer edge: last TP on AGB
~ r –, 3 .. 4
(Corradi et al. 2003)
Structure and expansion properties of Structure and expansion properties of Planetary Nebulae provide constraintsPlanetary Nebulae provide constraintson the final phases of AGB mass loss on the final phases of AGB mass loss
Structure and expansion properties of Structure and expansion properties of Planetary Nebulae provide constraintsPlanetary Nebulae provide constraintson the final phases of AGB mass loss on the final phases of AGB mass loss
AGBAGB ~ r ~ r ––, , 2.52.5 < < < < 3.53.5
Mass loss increases Mass loss increases towards end of AGBtowards end of AGBMass loss increases Mass loss increases towards end of AGBtowards end of AGB
AGB: > 2.5 (Kwok et al. 2002)
PPN: 3 < < 4 (Hrivnak & Bieging 2005)
How does the How does the central star windcentral star windinfluence the PN evolution ?influence the PN evolution ?
How does the How does the central star windcentral star windinfluence the PN evolution ?influence the PN evolution ?
Comparison of two different wind models:
Pauldrach et al. (1988)Pauldrach et al. (2004)
Pauldrach et al. (1988)Pauldrach et al. (2004)
Influence of central star wind on rim structureInfluence of central star wind on rim structure
CSPN wind: Pauldrach et al. (1988) CSPN wind: Pauldrach et al. (2004)
Rim: density gradient & velocity gradient reversed, increased width
ConclusionsConclusions
Time-dependent 1D modeling combining Single star evolution with mass loss + radiation-hydrodynamics of stellar winds + non-equilinrium low-density plasma physicscan explain the observed basic nebular structures:
X-ray emission of the central hot bubble radial intensity profiles in various emission lines internal kinematics and expansion properties structure and evolution of PN haloes
Models allow a classification of observed PNeModels allow a classification of observed PNein terms of evolutionary state and central star massin terms of evolutionary state and central star mass
DiscussionDiscussion & Outlook & Outlook
Main uncertainties of present models:Main uncertainties of present models:Mass loss during end of AGB and beyond Transition times
Improved models:Improved models: New AGB and post-AGB tracks with mass loss PN evolution for different metallicities PN evolution for Wolf-Rayet (WC) central stars