supernova neutrinos
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Supernova NeutrinosSupernova Neutrinos
Christian Y. Cardall
Oak Ridge National LaboratoryPhysics Division
University of Tennessee, KnoxvilleDepartment of Physics and Astronomy
Supernova NeutrinosChristian Y. CardallNOW 2006, Conca Specchiulla, Italy, 9-16 September 2006
Core-collapse supernovae Core-collapse supernovae
Survey of collapse simulationsSurvey of collapse simulations
Supernova neutrino signalsSupernova neutrino signals
New effects at small New effects at small ∆m∆m22??
Supernova NeutrinosChristian Y. CardallNOW 2006, Conca Specchiulla, Italy, 9-16 September 2006
Core-collapse supernovae Core-collapse supernovae
Supernova NeutrinosChristian Y. CardallNOW 2006, Conca Specchiulla, Italy, 9-16 September 2006
SN 1998aq(in NGC 3982)
Supernova NeutrinosChristian Y. CardallNOW 2006, Conca Specchiulla, Italy, 9-16 September 2006
Spectral classification of supernovae:
Filippenko (1997)
Type II(obvious H)
Type I(no H)
Type Ia(no H, strong Si)
Type Ic(no H, He, Si)
Type Ib(no H, obvious He)
Supernova NeutrinosChristian Y. CardallNOW 2006, Conca Specchiulla, Italy, 9-16 September 2006
Supernova NeutrinosChristian Y. CardallNOW 2006, Conca Specchiulla, Italy, 9-16 September 2006
Supernova NeutrinosChristian Y. CardallNOW 2006, Conca Specchiulla, Italy, 9-16 September 2006
Some key ingredients are
Neutrino transport/interactions,
Spatial dimensionality;Dependence on energy and angles;Relativity;Comprehensiveness of interactions;
(Magneto)Hydrodynamics/gravitation,
Dimensionality;Relativity;
Equation of state/composition,
Dense matter treatments;Number and evolution of nuclear species;
Diagnostics,
Accounting of lepton number;Accounting of energy;Accounting of momentum.
Supernova NeutrinosChristian Y. CardallNOW 2006, Conca Specchiulla, Italy, 9-16 September 2006
The observables to understand includeExplosion (and energy thereof);Neutrinos;Remnant properties,
Mass, spin, kick velocity, magnetic fields;
Gravitational waves;Element abundances;Measurements across the EM spectrum,
IR, optical, UV, X-ray, gamma-ray;images, light curves, spectra, polarimetry...
Supernova NeutrinosChristian Y. CardallNOW 2006, Conca Specchiulla, Italy, 9-16 September 2006
Survey of collapse simulations Survey of collapse simulations
Supernova NeutrinosChristian Y. CardallNOW 2006, Conca Specchiulla, Italy, 9-16 September 2006
2S 0M
1S 1M
3S 0M
1S 2M
2S 1M
1.5 2M
S 3S 1M
2S 3M
N GR N GR N GR N GR N GR N GR N GR N GR
1S N
GR
2S N
B
GR
B
3S N
B
GR
B
Mag
neto
hydr
odyn
amic
sNeutrino radiation transport
Supernova NeutrinosChristian Y. CardallNOW 2006, Conca Specchiulla, Italy, 9-16 September 2006
Two observables beyond explosion…Accretion continues until the stalled shock is
reinvigorated: relation between neutron star mass and delay to explosion
The abundance of nuclei with a closed shell of 50 neutrons
The electron fraction…
is set by neutrino interactions:
Supernova NeutrinosChristian Y. CardallNOW 2006, Conca Specchiulla, Italy, 9-16 September 2006
Fluid dynamics: 2D, 3D
Neutrino transport: 2D + 0D, 3D + 0D
Fryer & Warren (2002)Mezzacappa et al. (1998)
Fluid dynamics: 2D
Neutrino transport: 1D + 1D
Supernova NeutrinosChristian Y. CardallNOW 2006, Conca Specchiulla, Italy, 9-16 September 2006
2S 0M
1S 1M
3S 0M
1S 2M
2S 1M
1.5 2M
S 3S 1M
2S 3M
N GR N GR N GR N GR N GR N GR N GR N GR
1S N
GR
2S N
B
GR
B
3S N
B
GR
B
Mag
neto
hydr
odyn
amic
sNeutrino radiation transport
Neutron star mass too small; heating drives explosion too soon.
N=50 overproduction; Ye too low.
Supernova NeutrinosChristian Y. CardallNOW 2006, Conca Specchiulla, Italy, 9-16 September 2006
Fluid dynamics: 1D
Neutrino transport: 1D + 2D
Liebendörfer et al. (2001, 2004)
Rampp & Janka (2000, 2002)
Thompson, Burrows, & Pinto (2002)
Kitaura, Janka, & Hillebrandt (2006)
Supernova NeutrinosChristian Y. CardallNOW 2006, Conca Specchiulla, Italy, 9-16 September 2006
2S 0M
1S 1M
3S 0M
1S 2M
2S 1M
1.5 2M
S 3S 1M
2S 3M
N GR N GR N GR N GR N GR N GR N GR N GR
1S N
GR
2S N
B
GR
B
3S N
B
GR
B
Mag
neto
hydr
odyn
amic
sNeutrino radiation transport
Explosion only for 8-10 M stars with O-Ne-Mg cores.
Reasonable neutron star mass; accretion continues during delay.
Reasonable N=50 element production expected; ejected matter has Ye > 0.46.
May explain some subluminous Type II-P.
Supernova NeutrinosChristian Y. CardallNOW 2006, Conca Specchiulla, Italy, 9-16 September 2006
Fluid dynamics: 2D
Neutrino transport: 2D + 1D
Burrows et al. (2006)
Swesty & Myra (2005)
Supernova NeutrinosChristian Y. CardallNOW 2006, Conca Specchiulla, Italy, 9-16 September 2006
2S 0M
1S 1M
3S 0M
1S 2M
2S 1M
1.5 2M
S 3S 1M
2S 3M
N GR N GR N GR N GR N GR N GR N GR N GR
1S N
GR
2S N
B
GR
B
3S N
B
GR
B
Mag
neto
hydr
odyn
amic
sNeutrino radiation transport
Explosion for 11, 15, 25 M progenitors.
Some neutrino transport details left out; is the acoustic mechanism physical?
Reasonable neutron star mass; accretion continues during delay.
Not yet clear if Ye gives reasonable nucleosynthesis or if the model is resolved.
Supernova NeutrinosChristian Y. CardallNOW 2006, Conca Specchiulla, Italy, 9-16 September 2006
Fluid dynamics: 2D
Neutrino transport: 1.5D + 2D
Buras et al. (2006)
Supernova NeutrinosChristian Y. CardallNOW 2006, Conca Specchiulla, Italy, 9-16 September 2006
2S 0M
1S 1M
3S 0M
1S 2M
2S 1M
1.5 2M
S 3S 1M
2S 3M
N GR N GR N GR N GR N GR N GR N GR N GR
1S N
GR
2S N
B
GR
B
3S N
B
GR
B
Mag
neto
hydr
odyn
amic
sNeutrino radiation transport
Full 180º allows an 11 M star to explode; what about higher mass progenitors?
Reasonable neutron star mass; accretion continues during delay.
Reasonable N=50 element production expected; some of ejecta has Ye > 0.5.
Acoustic mechanism not yet probed.
Supernova NeutrinosChristian Y. CardallNOW 2006, Conca Specchiulla, Italy, 9-16 September 2006
2S 0M
1S 1M
3S 0M
1S 2M
2S 1M
1.5 2M
S 3S 1M
2S 3M
N GR N GR N GR N GR N GR N GR N GR N GR
1S N
GR
2S N
B
GR
B
3S N
B
GR
B
Mag
neto
hydr
odyn
amic
sNeutrino radiation transport
Supernova NeutrinosChristian Y. CardallNOW 2006, Conca Specchiulla, Italy, 9-16 September 2006
Supernova neutrino signals Supernova neutrino signals
Supernova NeutrinosChristian Y. CardallNOW 2006, Conca Specchiulla, Italy, 9-16 September 2006
Neutrino predictions ca. 1987
Did anyone do gravitational collapse as a Fermi problem?
Assume the stellar core is basically a white dwarf: a Chandrasekhar mass of 1.4 M and about 104 km.
Assume that the neutron star it collapses to is essentially a giant nucleus, and hence has density n = 0.16 fm-3.
From the mass and final density,
Supernova NeutrinosChristian Y. CardallNOW 2006, Conca Specchiulla, Italy, 9-16 September 2006
Neutrino predictions ca. 1987
How long will it take to collapse? The free-fall time scale is
The iron core is roughly half protons before collapse. Electron capture converts each proton to a neutron with the emission of an antineutrino.
Assume the neutrinos are trapped (check the consistency of this later). Then the number density of antineutrinos is half the final nucleon density.
Supernova NeutrinosChristian Y. CardallNOW 2006, Conca Specchiulla, Italy, 9-16 September 2006
Neutrino predictions ca. 1987
From the number density of antineutrinos, find their typical energy from the inter-particle spacing:
On what timescale will the neutrinos diffuse out?
This ‘validates’ the assumption of neutrino trapping.
Supernova NeutrinosChristian Y. CardallNOW 2006, Conca Specchiulla, Italy, 9-16 September 2006
Neutrino predictions ca. 1987
Almost forgot: the gravitational binding energy released during collapse will be released in neutrinos.
If neutrinos are trapped we expect all flavors to be produced. They will be emitted with a hierarchy of energies because differences in their interactions cause them to decouple at different radii:
Supernova NeutrinosChristian Y. CardallNOW 2006, Conca Specchiulla, Italy, 9-16 September 2006
Neutrino predictions ca. 1987
~ 1s hydrodynamic simulations with decent neutrino transport (Wilson 1984)
Supernova NeutrinosChristian Y. CardallNOW 2006, Conca Specchiulla, Italy, 9-16 September 2006
Burrows and Lattimer 1986
Neutrino predictions ca. 1987
~ 20s ‘stellar evolution’ with crude transport
Supernova NeutrinosChristian Y. CardallNOW 2006, Conca Specchiulla, Italy, 9-16 September 2006
SN 1987A
Tarantula Nebula
Supernova NeutrinosChristian Y. CardallNOW 2006, Conca Specchiulla, Italy, 9-16 September 2006
The lucky messengers…
Each “event” involves ~109 “messengers,”with at most 1 “detected”
SN1987A sent ~1058 “messengers,”with ~two dozen detected
Raffelt (1999)
Supernova NeutrinosChristian Y. CardallNOW 2006, Conca Specchiulla, Italy, 9-16 September 2006
Prediction vs. observationBurrows and Lattimer (1987)
Supernova NeutrinosChristian Y. CardallNOW 2006, Conca Specchiulla, Italy, 9-16 September 2006
A neutrino window into the supernova…L
iebendörfer et al. (2004)
Buras et al. (2005)
Supernova NeutrinosChristian Y. CardallNOW 2006, Conca Specchiulla, Italy, 9-16 September 2006
…could provide information about, for instance, rotation and the nuclear equation of state.
Thompson et al. (2005)Sumiyoshi et al. (2006)
Pons et al. (2001)
Supernova NeutrinosChristian Y. CardallNOW 2006, Conca Specchiulla, Italy, 9-16 September 2006
Neutrino mixing unknowns: 13 and hierarchyR
affelt (2005)
Supernova NeutrinosChristian Y. CardallNOW 2006, Conca Specchiulla, Italy, 9-16 September 2006
New effects at small New effects at small ∆m∆m22??
Supernova NeutrinosChristian Y. CardallNOW 2006, Conca Specchiulla, Italy, 9-16 September 2006
Duan et al. (2006)
Supernova NeutrinosChristian Y. CardallNOW 2006, Conca Specchiulla, Italy, 9-16 September 2006
Duan et al. (2006)
Supernova NeutrinosChristian Y. CardallNOW 2006, Conca Specchiulla, Italy, 9-16 September 2006
Core-collapse supernovae Core-collapse supernovae
Survey of collapse simulationsSurvey of collapse simulations
Supernova neutrino signalsSupernova neutrino signals
New effects at small New effects at small ∆m∆m22??
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