Recent 2D/3D Core-Collapse Supernovae Simulations Results
Obtained with the CHIMERA Code
Stephen W. Bruenn
bruenn@fau.edu
Santa Fe WorkShop, July 10, 09
Core Collapse Supernovae 101
2
1
neutrinos
3
6
4
7
Santa Fe WorkShop, July 10, 09
5
shock
Core Collapse Supernovae 101
neutrinos
light
ejecta
Neutron star
or black hole
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Core Collapse Supernova
Energetics
Photons ~ 1049 ergs
Ejecta Kinetic energy ~ 1050 - 1052 ergs
Neutrinos ~ 3x1053 ergs
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The Spherically Symmetric Cul de Sac
Matter Flow
Neutrino flow
Shock
_e + n p + ee + p n + e+
_e + n p + ee + p n + e+
Gain Radius
Protoneutron
Star
Cooling
Heating
-Spheres
Core Collapse Supernova
Asymmetries
γ
Polarization
Core collapse SN are polarized at ~1% level
Degree of polarization increases with decreasing envelope mass
Degree of polarization generally increases after optical maximum
Outward mixing of Ni in SN1987 A & Cas A
Axisymmetric ejecta of SN1987A
Early Emission of x-rays and gamma-rays from
SN1987A
Santa Fe WorkShop, July 10, 09
The Core Collapse Supernova Mechanism:
A Computational Challenge
Inherently multi-dimensional
Variety of complex physical processes that
need to be accurately modeled
Extremely nonlinear with many feedbacks
Explosions are marginal
Santa Fe WorkShop, July 10, 09
Core-Collapse Supernova Mechanisms
Magnetic Field Mechanism
Burrows, Dessart, Livne, Ott, & Murphy, ApJ, 644, 416, 2007 (2D RMHD)
Shibata Liu, Shapiro, & Stephens, Phys. Rev. D 74, 104026 (2D MHD, High res)
Dessart, Burrows, Livne, & Ott, ApJ, 669, 585, 2007 (2D RMHD)
Sawai, Kotake, & Yamada, ApJ, 672, 465, 2008 (2D MHD, offset dipole)
Mikami, Sato, Matsumoto, & Hanawa, ApJ, 683, 357, 2008 (3D MHD, rotated dipole)
Acoustic Mechansim
Burrows, Livne, Dessart, Ott, & Murphy, ApJ, 640, 878, 2007; ApJ, 655, 416, 2007
Neutrino Transport Mechanism
Buras, Janka, Rampp, & Kifonidis, A&A, 447, 1049, 2006; A&A 457, 281, 2006 (2D ray-by-ray plus)
Bruenn, Dirk, Mezzacappa, Hayes, Blondin, Hix, Messer, SciDAC 2006 (2D ray-by-ray plus)
Ott, Burrows, Dessart, & Livne, Ap. J. 685, 1069, 2008 (MGFLD, SN, isoenergetic)
Santa Fe WorkShop, July 10, 09
Magnetic Field Mechanism
Taps free energy
ofdifferential
rotation
Trot = 4
κ I
0.3
M
1.4M
R
10 km
2
Prot
2 ms
−2
B
1 B = 1051 ergs
Predicted rotational rates of newly formed neutron stars
3 - 15 ms (Heger, Woosley & Spruit, 2005)
Extrapolated periods of newly formed pulsars
Crab:
21 ms
PSR J0537-6910
10 ms
PSR B0540-69
39 ms
PSR B1509-58
20 ms
Problem: Need rapid rotation (not observed or predicted)
Santa Fe WorkShop, July 10, 09
Acoustic Mechanism
Anisotropic accretion onto inner core over time excites
core g-modes
Core eigenmodes (mainly L = 1) grow to large
amplitudes and radiate sound
Sound pulses steepen into shocks and deposit energy
and momentum in the shocked mantle powering an
explosion
Problem: Occurs late (many hundreds of milliseconds to
seconds post bounce), and only one group has seen it
Santa Fe WorkShop, July 10, 09
Neutrino Transport Mechanism
Matter Flow
Neutrino flow
Shock
_e + n p + ee + p n + e+
_e + n p + ee + p n + e+
Gain Radius
Protoneutron
Star
Cooling
Heating
-Spheres
Onset of Neutrino Driven Convection
shock
matter
gain radius
convection
-sphere
neutrinos
Cooling
Heating
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Onset of Neutrino Driven Convection (12 MO Progenitor)
40 ms
60 ms
80 ms
100 ms
Ratio of Advective to Convective Growth Timescales
W-H 12 Solar Mass Progenitor
t (advective)/t (convective)
4
40 ms postbunce
60 ms postbounce
80 ms postbounce
100 ms postbounce
120 ms postbounce
3
2
1
0
3
2
1
Polar Angle
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0
120 ms
The Standing Accretion Shock Inatability (SASI)
shock
matter
gain radius
-sphere
convection
SASI
neutrinos
Cooling
Heating
Santa Fe WorkShop, July 10, 09
ics
n
atio
Equ State
of
Neutrino
Transport
Gr
a
Sol vity
ver
s
ion
Hy
act
dro
Re
dyn
ar
am
cle
Nu
CHIMERA Code
1D, 2D, and 3D
Multi-D Hydro with Radial Ray Transport
Santa Fe WorkShop, July 10, 09
CHIMERA Collaboration
Stephen W. Bruenn
Florida Atlantic U.
Code Architect, Neutrino Transport
Anthony Mezzacappa
Oak Ridge National Lab
Project Leader & Science Advisor
John M. Blondin
North Carolina State
2D & 3D Hydro
W. Raph Hix
Oak Ridge National Lab
Nuclear Physics & Nuclear Network
O. E. Bronson Messer
Oak Ridge National Lab
Systems Advisor, Data Management
Pedro Marronette
Florida Atlantic U.
Gravity, Elliptic Solvers, GR Waves
Konstantin Yakunin
Florida Atlantic U.
Gravity, Elliptic Solvers, GR Waves
Charlotte Dirk
Florida Atlantic U.
Visualization
Ross Toedte
Oak Ridge National Lab
Visualization
Santa Fe WorkShop, July 10, 09
Progenitor Series
A suite of progenitor masses (12,15, 20, and
25 MO. ) ( Woosley and Heger, 2007 PhR)
(ongoing)
Progenitors of given mass evolved with
different equations of state (planned)
Progenitors of given mass evolved by
different groups (planned)
Progenitors of given mass with different
rotational profiles (planned)
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Progenitor Structure
1x1011
Progenitor vs enclosed mass
1x1010
1x109
Woosley-Heger 12
Woosley-Heger 15
Woosley-Heger 20
Woosley-Heger 25
1x108
1x107
1x106
1x105
1x104
1x103
0
0.5
1
1.5
2
2.5
3
Enclosed Mass [MO. ]
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3.5
4
4.5
20 MO 2D Simulation 256x256
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15 MO 2D Simulation 512x256
Supernova Connections
Neutron Stars
Nucleosynthesis
Supernovae
Black Holes
Neutrino Signatures
Gravitational Waves
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Explosion Energy vs Initial MS Mass
Explosion Energy versus Progenitor Mass
Explosion Energy [B]
Wossley-Heger 12, 15, 20, 25 Solar Mass Nonrotating Progenitors; 256 x 256 Spatial Resolution
0.8
W-H 12 solar mass progenitor
W-H 15 solar mass progenitor
W-H 20 solar mass progenitor
W-H 25 solar mass progenitor
0.6
0.4
0.2
0
0
0.2
0.4
0.6
0.8
Time from bounce [s]
Santa Fe WorkShop, July 10, 09
1
1.2
Sources of the Explosion Energy
Explosion Energy as a Function of Post-Bounce Time
W-H 20 Solar Mass Progenitor
0.7
Explosion energy
pdV work on ejected mass
Energy advection into ejected mass
Nuclear recombination of ejected mass
Neutrino energy deposition in ejected mass
Explosion Energy [B]
0.6
0.5
0.4
0.3
0.2
0.1
0
0
0.2
0.4
0.6
Time from bounce [s]
Santa Fe WorkShop, July 10, 09
0.8
1
Progenitor Fe Core, Neutron Star, and 56Ni Masses
Progenitor1 Fe Core1 N Star1
N Star2
56Ni1
12 MO
1.31
1.46
1.31
0.028
15 MO
1.42
1.57
1.42
< 0.01
20 MO
1.59
1.84
1.61
< 0.01
25 MO
1.71
1.87
1.63
0.077
1 Rest
mass
2 Gravitational mass
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Why Are We Getting Explosions?
Dimensional Effects:
Convection driven by neutrino heating
SASI (Standing Accretion Shock Instability)
Improved neutrino rates
Energy deposition by nuclear reactions
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Dimensional and Neutrino Rate Effects
Shock Radii vs Time from Bounce
W-H 15 Solar Mass Progenitor; Effect of Dimensionality and Neutrino Rates
Shock Radius [km]
8000
2D, complete nu-rates, mean radius
2D, complete nu-rates, mas radius
2D, complete nu-rates, min radius
2D, reduced nu-rates, mean radius
2D, reduced nu-rates, max radius
2D, reduced nu-rates, min radius
1D, complete nu-rates
1D, reduced nu_rates
6000
4000
2000
0
0
0.5
1
Time from Bounce [s]
Santa Fe WorkShop, July 10, 09
1.5
Role of the SASI
1E+26
1E+25
1E+24
1E+23
1E+22
1E+21
1E+20
1E+19
1E+18
1E+17
1E+16
1E+15
1E+14
1E+13
1E+12
1E+11
1E+10
1E+9
1E+8
15 M . Woosley-Heger
O
Mode
1
2
3
4
5
6
7
8
9
10
0
0.05
0.1
0.15
0.2
0.25
0.3
Time from bounce [s]
Santa Fe WorkShop, July 10, 09
0.35
0.4
0.45
Neutrinospheres
Neutrinospheres
Heating
Cooling
Protoneutron
Star
e’s
_
e’s
-sphere
_e
e-sphere
_
μ’s, _μ’s,
’s, ’s,
μ & -sphere
Lagrangian Tracer Particles for Nucleosynthesis
4000 - 8000 Lagrangian tracer particles in
each model (Lee & Hix)
Records thermodynamic state and spectral
neutrino history along its trajectory
Each tracer particle can be post-processed
by a full nuclear network
Santa Fe WorkShop, July 10, 09
Core-Collapse Supernova Nucleosynthesis
Infall
Intermediate mass elements
Shock
Shock ejection
-process Iron-Peak elements
Neutrinos
Radius
Wind
p-process
Heating
Cooling
Time
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r-process
15 MO Lagrangian and Shock Trajectories
O
Ne, Mg
Si
He O
Ni
n, p
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-p Process
Inclusion of neutrino interactions during nucleosynthesis
opens up a new chain of nuclear reactions
Fröhlich, Martínez-Pinedo, Liebendörfer, Thielemann, Bravo, Hix, Langake, Zinner, PRL, 96, 142502, 2006
Pruet, Hoffman, Woosley, Janka, Buras, ApJ, 644, 1028, 2006
Neutrino absorption on proton rich material creates
residual neutron abundance [ ν̄e + p → n + e+ ]
Neutron captures on proton-rich seeds bypasses the
64Ge bottleneck
IPMU - Focus Week on Messengers of Supernova Explosions, November 17-21
Neutrinos and Nucleosynthesis
Despite the perceived importance of neutrinos to the core collapse
mechanism, models of the nucleosynthesis have largely ignored this
important effect.
Nucleosynthesis from parameterized neutrino-powered supernova models
show several notable improvements.
Elemental abundances
of Sc, Cu & Zn closer to
those observed in metalpoor stars.
Fröhlich, … (2006)
Over production of
neutron-rich iron and
nickel (A~62) reduced.
Potential source of light
p-process nuclei (76Se,
80Kr,84Sr,92,94Mo,96,98Ru)
by
the p-process.
Santa Fe WorkShop, July 10, 09
CHIMERA Nucleosynthesis
With successful, selfconsistent supernova
models, we can make
better predictions of the
nuclear composition and
begin to use
nucleosynthesis to
constrain our models.
Lee (PhD 2008)
Our preliminary postprocessing results also
show proton-rich ejecta
and p-process (dotted
lines), but more weakly
than previous results.
However, strength of the p-process depends on the expansion rate, which
is extrapolated in these preliminary calculations.
Santa Fe WorkShop, July 10, 09
Dimensional Effects on Neutrino Luminosities
70
15 M . Woosley-Heger
O
60
50
_ e
e
_ x
x
40
30
20
10
1D
2D
0
0
0.1
0.2
0.3
0.4
0.5
Time from Bounce [s]
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0.6
0.7
Dimensional Effects on Neutrino rms Energies
25
15 M . Woosley-Heger
O
20
_ e
e
_x
x
15
10
5
1D
2D
0
0
0.1
0.2
0.3
0.4
0.5
Time from Bounce [s]
Santa Fe WorkShop, July 10, 09
0.6
0.7
Gravitational Wave Emission
Acoustic
Magnetic
Source
Amplitude at 10 kpc
Core bounce dominated by nuclear pressure
Bounce
Small peak GW’s |hmax | < 5 × 10−22
ΩFe core < 1 − 1.5 rad s−1
Core bounce dominated by nuclear pressure
Bounce
1 − 2 rad s−1 < ΩFe core < 6 − 13 rad s−1 Sizable peak GW’s 5 × 10−22 < |hmax | < 2 × 10−20
Slow core bounce dominated by centrifugal forces
Bounce
−1
Longer duration 3.5 × 10−21 < |hmax | < 7.5 × 10−21
6 − 13 rad s < ΩFe core
Rot instability at ΩFe core < (Ωsec , Ωdyn )
1 × 10−21 < |hmax | < 5 × 10−21
Prompt Convection
1 × 10−22 < |hmax | < 6 × 10−22
PNS Convection
1 × 10−23 < |hmax | < 5 × 10−23
Neutrino Driven Convection
1 × 10−23 < |hmax | < 1 × 10−22
Protoneutron Star g-Mode Pulsations
1 × 10−21 < |hmax | < 5 × 10−20
ΩFe core ∼ 5 × 10−2 rad s−1
Heger, Woosley, Spruit Progenitor
(ApJ, 626, 350, 2005)
Ott, C. D. arXiv:0809.0695v2; Dimmelmeier, J. A. et al. Phys. Rev. D., 78, 064056; Ott, C. D. Muller, E. et al. ApJ, 603, 221, 2004; Ott, C. D. et al. Phys. Rev. Lett. 96,
201102; Marek, A. ,; Fryer C. L. ApJ 609, 288, 2004; Fryer, C. L. ApJ Lett. 601, L175, 2004.
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Gravitaional Waves from the CHIMERA Models
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Gravitaional Waves from the CHIMERA Models
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3D 15 MO. Model Simulation
304 nonuniformly spaced radial zones out
to 2000 km
78 evenly spaced angular zones from 0 to
180 degrees
156 evenly spaced azimuthal zones from 0
to 360 degrees
4 neutrino flavors, 20 energy zones from 4
to 400 MEV for each flavor
Requires 11,552 processors
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3D 15 MO. Model Simulation
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3D 15 MO. Model Simulation
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Status of the Neutrino Transport Model
Arizona-Israeli
Group
Munich Group
Oak-Ridge-FAUNCState Group
No explosions
Explosions at late
times for some
models
Explosions at earlier
times for
12 - 25 MO
Santa Fe WorkShop, July 10, 09
2D MGFLD Transport
No energy exchanging
neutrino interactions
Newtonian Hydro
Ray-by-ray plus VEF Transport
Approximate GR hydro
etc. ....
Ray-by-ray plus MGFLD
Transport
Approximate GR hydro
etc. ....
Conclusions
2D simulations with spectral neutrino
transport exhibit explosions for each of the
Woosley-Heger 12, 15, 20, & 25 solar mass
models. 3D simulation in progress.
However, comparisons of the 2D
simulations with other groups have yet to
show a convergence of results.
But what about neutrino-neutrino flavor
changing interactions????
Santa Fe WorkShop, July 10, 09
Work in Progress
Investigate the observables of the
exploding models---nucleosynthesis,
neutrino and gravitational wave signatures,
neutron star masses and kick velocities
Use a singularity-free grid
Incorporate magnetic fields
Incorporate flavor changing reactions
Deploy Genasis
Santa Fe WorkShop, July 10, 09
The End
bruenn@fau.edu
physics.fau.edu/~bruenn
Santa Fe WorkShop, July 10, 09