III. Supernova Neutrinos -

Georg Raffelt, Max-Planck-Institut für Physik, München, Germany JIGSAW 07, 12-23 Feb 2007, TIFR, Mumbai, India

III. Supernova NeutrinosIII. Supernova Neutrinos


Sanduleak Sanduleak −−69 20269 202

Large Magellanic Cloud Large Magellanic Cloud Distance 50 kpcDistance 50 kpc(160.000 light years)(160.000 light years)

Tarantula NebulaTarantula Nebula



Sanduleak Sanduleak −−69 20269 202

Large Magellanic Cloud Large Magellanic Cloud Distance 50 kpcDistance 50 kpc(160.000 light years)(160.000 light years)

Tarantula NebulaTarantula Nebula

Supernova 1987ASupernova 1987A23 February 198723 February 1987

Georg Raffelt, Max-Planck-Institut für Physik, München, Germany JIGSAW 07, 12-23 Feb 2007, TIFR, Mumbai, India Georg Raffelt, Max-Planck-Institut für Physik, München, Germany JIGSAW 07, 12-23 Feb 2007, TIFR, Mumbai, IndiaGeorg Raffelt, Max-Planck-Institut für Physik, München, Germany JIGSAW 07, 12-23 Feb 2007, TIFR, Mumbai, India


Supernovae: Almost as Bright as GalaxiesSupernovae: Almost as Bright as Galaxies

SN 1994D in NGC 4526SN 1994D in NGC 4526SN 1998S in NGC 3877SN 1998S in NGC 3877

Georg Raffelt, Max-Planck-Institut für Physik, München, Germany JIGSAW 07, 12-23 Feb 2007, TIFR, Mumbai, IndiaGeorg Raffelt, Max-Planck-Institut für Physik, München, Germany JIGSAW 07, 12-23 Feb 2007, TIFR, Mumbai, India


Mass Transfer in Binary StarsMass Transfer in Binary Stars

Binary system of white dwarfBinary system of white dwarfand evolved companion star,and evolved companion star,beginning to fill the “Roche lobe”beginning to fill the “Roche lobe”

RocheRoche--lobe overflow feeds masslobe overflow feeds massto the compact starto the compact star


HeliumHelium--burning starburning star

HeliumHeliumBurningBurning

HydrogenHydrogenBurningBurning

MainMain--sequence starsequence star

Hydrogen BurningHydrogen Burning

Stellar Collapse and Supernova ExplosionStellar Collapse and Supernova Explosion


HeliumHelium--burning starburning star

HeliumHeliumBurningBurning

HydrogenHydrogenBurningBurning

MainMain--sequence starsequence star

Hydrogen BurningHydrogen Burning

Onion structureOnion structure

Degenerate iron core:Degenerate iron core:ρρ ≈≈ 101099 g cmg cm−−33

T T ≈≈ 101010 10 KKMMFeFe ≈≈ 1.5 M1.5 MsunsunRRFeFe ≈≈ 8000 km8000 km

Collapse (implosion)Collapse (implosion)



Collapse (implosion)Collapse (implosion)ExplosionExplosionNewborn Neutron StarNewborn Neutron Star

~ 50 km~ 50 km

ProtoProto--Neutron StarNeutron Starρρ ≈≈ ρρnucnuc == 33 ××10101414 g cmg cm−−33

T T ≈≈ 30 MeV30 MeV

NeutrinoNeutrinoCoolingCooling



Newborn Neutron StarNewborn Neutron Star

~ 50 km~ 50 km

ProtoProto--Neutron StarNeutron Starρρ ≈≈ ρρnucnuc == 33 ××10101414 g cmg cm−−33

T T ≈≈ 30 MeV30 MeV

NeutrinoNeutrinoCoolingCooling

Gravitational binding energyGravitational binding energy

EEbb ≈≈ 3 3 ×× 10105353 erg erg ≈≈ 17% M17% MSUN SUN cc22

This shows up as This shows up as 99% Neutrinos99% Neutrinos

1% Kinetic energy of explosion1% Kinetic energy of explosion(1% of this into cosmic rays) (1% of this into cosmic rays)

0.01% Photons, outshine host galaxy0.01% Photons, outshine host galaxy

Neutrino luminosityNeutrino luminosity

LLνν ≈≈ 3 3 ×× 10105353 erg / 3 secerg / 3 sec≈≈ 3 3 ×× 10101919 LLSUNSUN

While it lasts, outshines the entireWhile it lasts, outshines the entirevisible universevisible universe



Neutrino Signal of Supernova 1987ANeutrino Signal of Supernova 1987A

Within clock uncertainties,Within clock uncertainties,signals are contemporaneoussignals are contemporaneous

KamiokandeKamiokande--II (Japan)II (Japan)Water Cherenkov detectorWater Cherenkov detector2140 tons2140 tonsClock uncertainty Clock uncertainty ±±1 min1 min

IrvineIrvine--MichiganMichigan--Brookhaven (US)Brookhaven (US)Water Cherenkov detectorWater Cherenkov detector6800 tons6800 tonsClock uncertainty Clock uncertainty ±±50 ms50 ms

Baksan Scintillator TelescopeBaksan Scintillator Telescope(Soviet Union), 200 tons(Soviet Union), 200 tonsRandom event cluster ~ 0.7/dayRandom event cluster ~ 0.7/dayClock uncertainty Clock uncertainty +2/+2/--54 s54 s


Supernova Remnant in Cas A (SN 1667Supernova Remnant in Cas A (SN 1667?)?)

Chandra Chandra xx--ray imageray image

Non-pulsarcompact remnant(could be black hole)

Non-pulsarcompact remnant(could be black hole)


The Crab PulsarThe Crab Pulsar

Chandra x-ray imagesChandra x-ray images



Baade and Zwicky were the first to speculate about a connectionBaade and Zwicky were the first to speculate about a connectionbetween supernova explosions and neutronbetween supernova explosions and neutron--star formationstar formation

[Phy[Phys. Rev. 45 (1934) 138]s. Rev. 45 (1934) 138]

Walter Baade (1893Walter Baade (1893−−1960)1960) Fritz Zwicky (1898Fritz Zwicky (1898−−1974)1974)


Thermonuclear vs. CoreThermonuclear vs. Core--Collapse SupernovaeCollapse Supernovae

Core collapse (Type II, Ib/c)Core collapse (Type II, Ib/c)Thermonuclear (Type Ia)Thermonuclear (Type Ia)

•• CarbonCarbon--oxygen white dwarfoxygen white dwarf(remnant of(remnant oflowlow--mass star)mass star)

•• Accretes matterAccretes matterfrom companionfrom companion

•• Degenerate iron coreDegenerate iron coreof evolved massive starof evolved massive star

•• Accretes matter Accretes matter by nuclear burningby nuclear burningat its surfaceat its surface

Chandrasekhar limit is reached Chandrasekhar limit is reached −− MMChCh ≈≈ 1.5 M1.5 Msunsun (2Y(2Yee))22

C O L L A P S E S E T S I NC O L L A P S E S E T S I N

Nuclear burning of C and O ignitesNuclear burning of C and O ignites→→ Nuclear deflagrationNuclear deflagration((““Fusion bombFusion bomb”” triggered by collapse)triggered by collapse)

Collapse to nuclear densityCollapse to nuclear densityBounce & shock Bounce & shock Implosion Implosion →→ ExplosionExplosion

Gain of nuclear binding energyGain of nuclear binding energy~ 1 MeV per nucleon ~ 1 MeV per nucleon

Gain of gravitational binding energyGain of gravitational binding energy~~ 100 MeV per nucleon100 MeV per nucleon99% into neutrinos 99% into neutrinos

Powered by gravityPowered by gravityPowered by nuclear binding energyPowered by nuclear binding energy

Comparable Comparable ““visiblevisible”” energy release of energy release of ~ 3 ~ 3 ×× 10105151ergerg


No HydrogenNo Hydrogen HydrogenHydrogenSpectrumSpectrum

No SiliconNo SiliconSiliconSilicon

No HydrogenNo Hydrogen HydrogenHydrogenSpectrumSpectrum

Spectral Classification of SupernovaeSpectral Classification of Supernovae

Spectral TypeSpectral Type IbIb IcIc IIIIIaIa

No HeliumNo HeliumHeliumHelium

No SiliconNo SiliconSiliconSilicon

No HydrogenNo Hydrogen HydrogenHydrogen

SpectrumSpectrum

PhysicalPhysicalMechanismMechanism

NuclearNuclearexplosion ofexplosion of

lowlow--mass starmass star

Core collapse of evolved massive starCore collapse of evolved massive star(may have lost its hydrogen or even helium(may have lost its hydrogen or even helium

envelope during redenvelope during red--giant evolution)giant evolution)

Light CurveLight Curve ReproducibleReproducible Large variationsLarge variations

CompactCompactRemnantRemnant NoneNone Neutron star (typically appears as pulsar)Neutron star (typically appears as pulsar)

Sometimes black hole ?Sometimes black hole ?

Rate / hRate / h22 SNuSNu 0.36 0.36 ±± 0.110.11 0.71 0.71 ±± 0.340.340.14 0.14 ±± 0.070.07

ObservedObserved Total Total ∼∼ 2000 as of today (nowadays 2000 as of today (nowadays ∼∼200/year)200/year)

NeutrinosNeutrinos ∼∼ 100 100 ×× Visible energyVisible energyInsignificantInsignificant


Universal Supernova Ia Light CurveUniversal Supernova Ia Light Curve

Supernova Ia lightcurves areSupernova Ia lightcurves areempirically a 1empirically a 1--parameter familyparameter family

After transformationAfter transformationa universal light curve,a universal light curve,i.e. a dei.e. a de--facto standard candlefacto standard candle


Examples for SN II Light CurvesExamples for SN II Light Curves

Cappellaro & Turatto,Cappellaro & Turatto,astroastro--ph/0012455ph/0012455

Powered by Powered by radioactive decay of radioactive decay of 5656CoCo

SN 1987ASN 1987A


Supernovae the Power Supply for Cosmic Rays?Supernovae the Power Supply for Cosmic Rays?

Suggestive of supernovae:Suggestive of supernovae:

•• One SN explosion deposits ~ 3 One SN explosion deposits ~ 3 ×× 10105151 erg in kinetic energy oferg in kinetic energy ofejecta into the interstellar medium (ISM)ejecta into the interstellar medium (ISM)

•• Rate approx. 1 SN / 30 years / galaxyRate approx. 1 SN / 30 years / galaxy

Total average energy deposition:Total average energy deposition: LLSNSN ≈≈ 3 3 ×× 10104242 erg/s erg/s ≈≈ 50 50 LLCRCR

Required power supply LRequired power supply LCRCR = V= VDD ρρCRCR//ττresres≈≈ 5 5 ×× 10104040 erg/s erg/s ≈≈ 101077 LLSunSun

Disk volumeDisk volume VVD D = = ππ RR22 d d ≈≈ ππ (15 kpc)(15 kpc)22 200 pc 200 pc ≈≈ 4 4 ×× 10106666 cmcm33

Energy density in CRsEnergy density in CRs ρρCR CR ≈≈ 1 eV / cm1 eV / cm33

Residence time in galaxyResidence time in galaxy ττres res ≈≈ 6 6 ×× 101066 yrsyrs

Efficiency of a few percent requiredEfficiency of a few percent required


Explosion Mechanismfor Core-Collapse SNeExplosion Mechanismfor Core-Collapse SNe

Georg Raffelt, Max-Planck-Institut für Physik, München, Germany JIGSAW 07, 12-23 Feb 2007, TIFR, Mumbai, India Georg Raffelt, Max-Planck-Institut für Physik, München, Germany JIGSAW 07, 12-23 Feb 2007, TIFR, Mumbai, India

Collapse and Prompt ExplosionCollapse and Prompt Explosion

Supernova explosion primarily a hydrodynamical phenomenonSupernova explosion primarily a hydrodynamical phenomenon

Movies by J.A.Font, Numerical Hydrodynamics in General RelativitMovies by J.A.Font, Numerical Hydrodynamics in General Relativityyhttp://www.livingreviews.orghttp://www.livingreviews.org

VelocityVelocity DensityDensity


Failed ExplosionFailed Explosion

SphericallySpherically symmetricsymmetricsimulation of a 15 Msimulation of a 15 Msunsunstellar model stellar model with statewith state--ofof--thethe--artartneutrino transportneutrino transport

Movie courtesy ofMovie courtesy ofBronson Messer,Bronson Messer,Oakridge group (2001)Oakridge group (2001)


Why No Prompt Explosion?Why No Prompt Explosion?

DissociatedDissociatedMaterialMaterial

(n, p, e, (n, p, e, νν))

•• 0.1 M0.1 Msunsun of iron has a of iron has a nuclear binding energynuclear binding energy≈≈ 1.7 1.7 ×× 10105151 ergerg

•• Comparable toComparable toexplosion energyexplosion energy

•• Shock wave forms Shock wave forms within the iron corewithin the iron core

•• Dissipates its energy Dissipates its energy by dissociating the by dissociating the remaining layer of iron remaining layer of iron


Neutrinos to the RescueNeutrinos to the Rescue

Picture adapted from Janka, astroPicture adapted from Janka, astro--ph/0008432ph/0008432

Neutrino heatingNeutrino heatingincreases pressureincreases pressurebehind shock frontbehind shock front


Supernova Delayed Explosion ScenarioSupernova Delayed Explosion Scenario


Delayed ExplosionDelayed Explosion

Wilson, Proc. Univ. Illinois Meeting on Num. Astrophys.(1982)Wilson, Proc. Univ. Illinois Meeting on Num. Astrophys.(1982)Bethe & Wilson, ApJ 295 (1985) 14Bethe & Wilson, ApJ 295 (1985) 14


Spherical Symmetry in Astrophysics :-)Spherical Symmetry in Astrophysics :-)

Crab NebulaCrab Nebula

EtaCarinaeEtaCarinae

SN 1987ASN 1987A

Cas ACas A

Crab PulsarCrab

Pulsar

SNR G5.4-1.2PSR 1757-24SNR G5.4-1.2PSR 1757-24

[Adapted after a slide by A.Burrows][Adapted after a slide by A.Burrows]

Convection in SN simulationsConvection in SN simulations



Parametric 2D Studies (180º) by Garching GroupParametric 2D Studies (180º) by Garching Group

•• If explosion developsIf explosion developsslowly, convectiveslowly, convectivestructures have timestructures have timeto merge to lowto merge to low(l = 1 or 2) mode(l = 1 or 2) modeflowflow

•• Very asymmetricVery asymmetricshock expansionshock expansionand mass ejectionand mass ejectionalthough boundaryalthough boundaryneutrino flux is neutrino flux is isotropicisotropic

(Scheck et al., PRL(Scheck et al., PRL2004 and PhD Thesis)2004 and PhD Thesis)


Parametric 3D Studies by Garching GroupParametric 3D Studies by Garching Group

•• First explosions inFirst explosions in3D show also very3D show also verylarge asymmetrylarge asymmetry

•• Convection growsConvection growsfaster than in 2Dfaster than in 2D

•• Explosion energyExplosion energysomewhat highersomewhat higher

(L. Scheck(L. ScheckPhD Thesis 2004)PhD Thesis 2004)


Parametric 3D Studies by Garching GroupParametric 3D Studies by Garching Group


Convection to the RescueConvection to the Rescue

Picture adapted from Janka, astroPicture adapted from Janka, astro--ph/0008432ph/0008432

Convection dredges energyConvection dredges energyfrom the neutron starfrom the neutron star

to the shock waveto the shock wave


Exploding Models (8Exploding Models (8--10 Solar Masses) with O10 Solar Masses) with O--NeNe--CoresCores

Kitaura, Janka & Hillebrandt: “Explosions of Kitaura, Janka & Hillebrandt: “Explosions of OO--NeNe--Mg cores, the Crab supernova,Mg cores, the Crab supernova,and subluminous type IIand subluminous type II--P supernovae”, astroP supernovae”, astro--ph/0512065ph/0512065


HighHigh--Velocity PulsarsVelocity Pulsars

FalseFalse--color radio image of the SNR G5.4color radio image of the SNR G5.4--1.21.2and the young radio pulsar PSR 1757and the young radio pulsar PSR 1757--24 24 (v = 1300(v = 1300−−1700 km/s away from the gal. plane)1700 km/s away from the gal. plane)

Pulsar velocity distributionPulsar velocity distribution[Lyne & Lorimer, Nature 369 (1994) 127][Lyne & Lorimer, Nature 369 (1994) 127]

Galactic escapeGalactic escapevelocity ~ 600 km/svelocity ~ 600 km/s


What Accelerates the Pulsars?What Accelerates the Pulsars?

Hydrodynamically driven kicksHydrodynamically driven kicks•• Asymmetric matter ejection, but is convection enough Asymmetric matter ejection, but is convection enough •• PrePre--collapse asymmetry, perhaps caused by overstable collapse asymmetry, perhaps caused by overstable

oscillations of preoscillations of pre--supernova core? supernova core?

MatterMatterRocketRocket

PhotonPhotonRocketRocket

Electromagnetically driven acceleration:Electromagnetically driven acceleration:OffOff--center global magnetic dipole moment & rotationcenter global magnetic dipole moment & rotationaccelerates star in one direction.accelerates star in one direction.(Slow process (Slow process –– not a “kick”)not a “kick”)

Dong Lai, Neutron Star Kicks and Asymmetric Supernovae, astroDong Lai, Neutron Star Kicks and Asymmetric Supernovae, astro--ph/0012049 ph/0012049

Required neutrino Required neutrino asymmetryasymmetry

Caused by BCaused by B--field induced asymmetry of neutrino transportfield induced asymmetry of neutrino transportcoefficients (parity violation, dispersion effects & oscillatiocoefficients (parity violation, dispersion effects & oscillations,ns,asymmetric field distribution, ...)? asymmetric field distribution, ...)? Typically requires huge fields > 10Typically requires huge fields > 101515 Gauss Gauss

NeutrinoNeutrinoRocketRocket

⎟⎟⎠

⎞⎜⎜⎝

⎛⎟⎟⎠

⎞⎜⎜⎝

⎛ ×s/km1000

vE

erg103%8.2 kick

tot

53

⎟⎟⎠

⎞⎜⎜⎝

⎛⎟⎟⎠

⎞⎜⎜⎝

⎛ ×s/km1000

vE

erg103%8.2 kick

tot

53


Gravitational Waves from CoreGravitational Waves from Core--Collapse SupernovaeCollapse Supernovae

MMüüller, Rampp, Buras, Janka, & Shoemaker,ller, Rampp, Buras, Janka, & Shoemaker,“Towards gravitational wave signals from“Towards gravitational wave signals fromrealistic core collapse supernova models,”realistic core collapse supernova models,”astroastro--ph/0309833ph/0309833

The gravitationalThe gravitational--wave signal from convectionwave signal from convectionis a generic and dominating featureis a generic and dominating feature

BounceBounce

ConvectionConvection

Asymmetric neutrino emissionAsymmetric neutrino emission


Novel Forms of Energy Transfer?Novel Forms of Energy Transfer?

New particles or neutrinos with novel properties could provide aNew particles or neutrinos with novel properties could provide achannel of energy transfer from proto neutron star to shock wavechannel of energy transfer from proto neutron star to shock wave

Must not transfer too much energy: Limits on decaying neutrinosMust not transfer too much energy: Limits on decaying neutrinos[Falk & Schramm, PLB 79 (1978) 511][Falk & Schramm, PLB 79 (1978) 511]


Shock Revival by Novel Particles?Shock Revival by Novel Particles?


Viable Scenario with AxionViable Scenario with Axion--Like ParticlesLike Particles

Berezhiani & Drago, PLB 473 (2000) 281 Berezhiani & Drago, PLB 473 (2000) 281

Apparently consistent with f Apparently consistent with f == few 10few 1055 GeV and m GeV and m == few MeVfew MeVNot excluded by other arguments, but also not independently motiNot excluded by other arguments, but also not independently motivatedvated

StallingStallingshockshockwavewave

DecayDecay−+ +→ eea −+ +→ eea

PNSPNS Thermal flux of axionThermal flux of axion--likelikeparticles from “axion sphere”particles from “axion sphere”

Coupled to nuclear mediumCoupled to nuclear mediumby bremsstrahlungby bremsstrahlung

aNNNN ++→+ aNNNN ++→+

af1

L e5e µµ ∂ψγγψ= a

f1

L e5e µµ ∂ψγγψ=a

f1

L N5N µµ ∂ψγγψ= a

f1

L N5N µµ ∂ψγγψ=


Swapping Neutrino Spectra by OscillationsSwapping Neutrino Spectra by Oscillations


Effective energy Effective energy transfertransfer

−+→+ν epne−+→+ν epne++→+ν enpe++→+ν enpe

Not effective Not effective +− +→ν+ν ee +− +→ν+ν ee

PNSPNS

ννeewith with ⟨⟨EE⟩⟩ ≈≈ 12 MeV

12 MeV

ννµµ with with ⟨⟨EE⟩⟩ ≈≈ 20 MeV

20 MeV


Swapping Neutrino Spectra by OscillationsSwapping Neutrino Spectra by Oscillations

Swapping neutrino spectra by flavor oscillations enhances the rSwapping neutrino spectra by flavor oscillations enhances the rate of energyate of energytransfer to stalling shock wave [Fuller et al., ApJ 389 (1992) transfer to stalling shock wave [Fuller et al., ApJ 389 (1992) 517]517]


PNSPNS

νν eewith with

⟨⟨EE⟩⟩ ≈≈ 12 MeV12 MeV

νν µµwith with

⟨⟨EE⟩⟩ ≈≈ 12 MeV12 MeV

ννµµ with with ⟨⟨EE⟩⟩ ≈≈ 20 MeV

20 MeV ννee with with ⟨⟨EE⟩⟩ ≈≈ 20 MeV

20 MeV

FlavorFlavorOscillationsOscillations

Effective energy Effective energy transfertransfer


Not effective Not effective +− +→ν+ν ee +− +→ν+ν ee


Neutrinos fromCore-Collapse Supernovae

Neutrinos fromCore-Collapse Supernovae



Structure of Supernova Neutrino SignalStructure of Supernova Neutrino Signal

1.1. Collapse (infall phase)Collapse (infall phase)2.2. Shock break outShock break out3.3. Matter accretionMatter accretion4.4. KelvinKelvin--Helmholtz coolingHelmholtz cooling

Traps Traps neutrinosneutrinosand and leptonleptonnumbernumberof outerof outercore core layerslayers


Neutronization Burst as a Standard CandleNeutronization Burst as a Standard Candle

Different MassDifferent Mass Neutrino TransportNeutrino Transport Nuclear EoSNuclear EoS

KachelriessKachelriess,,TomàsTomàs, , BurasBuras,,JankaJanka, , MarekMarek& & RamppRampp,,astroastro--phph/0412082/0412082

If mixingIf mixingscenario isscenario isknown,known,perhaps bestperhaps bestmethod tomethod todeterminedetermineSN distance,SN distance,especially ifespecially ifobscuredobscured

(better than(better than55--10%)10%)


What determines the size of the PNS?What determines the size of the PNS?

MassMass

Chandrasekhar mass of iron core of progenitor starChandrasekhar mass of iron core of progenitor star

Dimensional analysis:Dimensional analysis:

Same number from zeroSame number from zero--T polytropic modelT polytropic modelsun

2N

3Pl

2N

23NCh M5.1mmmGM ≈=≈ −−−

sun2

N3Pl

2N

23NCh M5.1mmmGM ≈=≈ −−−

DensityDensitySupported by nucleon degeneracy pressureSupported by nucleon degeneracy pressure

Nuclear density Nuclear density 314nuc cmg103 −×=ρ≈ρ 314nuc cmg103 −×=ρ≈ρ

RadiusRadius Ch3

nuc MR3

4=ρ

πCh

3nuc MR

34

=ρπ

km6.10R ≈ km6.10R ≈

SchwarzschildSchwarzschildRadiusRadius

GeneralGeneral

HereHere

MG2R NS = MG2R NS =

km6.4mm2MG2R 2NPlChNS === − km6.4mm2MG2R 2NPlChNS === −


What determines the neutrino energies?What determines the neutrino energies?

DegenerateDegenerateCoreCore

PNSPNSAtmosphereAtmosphere

RR

Gravitational potential of a given nucleonGravitational potential of a given nucleon

ΦΦ = = −−GGNNMMPNSPNSmmNN RR−−11

With MWith MPNSPNS ≈≈ 1.5 M1.5 Msunsun and R and R ≈≈ 30 km30 km

ΦΦ ≈≈ −− 27 MeV27 MeV

Virial theorem (hydrostatic equilibrium)Virial theorem (hydrostatic equilibrium)

assuming nondegenerate conditions,assuming nondegenerate conditions,

⟨⟨EEkinkin⟩⟩ = = −− ½ ½ ⟨⟨ΦΦ⟩⟩ ≈≈ 13 MeV13 MeV

Thermal equilibriumThermal equilibrium

T = (2/3) T = (2/3) ⟨⟨EEkinkin⟩⟩ ≈≈ 9 MeV9 MeV

•• If the protoIf the proto--neutron star (PNS) atmosphere is nondegenerate, neutron star (PNS) atmosphere is nondegenerate, its temperature is determined by the gravitational potential its temperature is determined by the gravitational potential at the surfaceat the surfaceof the degenerate core and found in the ~ 10 MeV rangeof the degenerate core and found in the ~ 10 MeV range

•• Core contracts by accretion and/or cooling Core contracts by accretion and/or cooling →→ T increasesT increases


What determines the time scale?What determines the time scale?

Main neutrinoMain neutrinoreactionsreactions

Electron flavorElectron flavor

Other flavorsOther flavors


ν+→+ν NNe ν+→+ν NNe

NeutralNeutral--currentcurrentscatteringscatteringcross sectioncross section

224022

F

2A

2V

MeV100E

cm102EGC3C

)NN( ⎟⎟⎠

⎞⎜⎜⎝

⎛×≈

π

+=ν→νσ ν−

ν

224022

F

2A

2V

MeV100E

cm102EGC3C

)NN( ⎟⎟⎠

⎞⎜⎜⎝

⎛×≈

π

+=ν→νσ ν−

ν

Nucleon densityNucleon density 338

N

nucB cm108.1

mn −×≈

ρ= 338

N

nucB cm108.1

mn −×≈

ρ=

Scattering rateScattering rate2

19B MeV100

Es101.1n ⎟⎟

⎠

⎞⎜⎜⎝

⎛×≈σ=Γ ν−

219

B MeV100E

s101.1n ⎟⎟⎠

⎞⎜⎜⎝

⎛×≈σ=Γ ν−

Mean free pathMean free path2

1B E

MeV100cm28)n( ⎟⎟

⎠

⎞⎜⎜⎝

⎛≈σ=λ

ν

−2

1B E

MeV100cm28)n( ⎟⎟

⎠

⎞⎜⎜⎝

⎛≈σ=λ

ν

−

Diffusion timeDiffusion time222

diff MeV100E

km10R

sec2.1R

t ⎟⎟⎠

⎞⎜⎜⎝

⎛⎟⎟⎠

⎞⎜⎜⎝

⎛≈

λ≈ ν

222diff MeV100

Ekm10R

sec2.1R

t ⎟⎟⎠

⎞⎜⎜⎝

⎛⎟⎟⎠

⎞⎜⎜⎝

⎛≈

λ≈ ν


Convection in Proto Neutron StarConvection in Proto Neutron Star

Keil,Keil, JankaJanka && Müller,Müller, ApJApJ 473473 (1996)(1996) L111L111

Time scale of deleptonization increased Time scale of deleptonization increased by ~ factor 2, i.e. same generalby ~ factor 2, i.e. same generalmagnitude as diffusive transportmagnitude as diffusive transport

Driving Driving ConvectionConvection

Convects by Convects by overshootingovershooting

StableStable

LeptonLepton--rich region

rich region


FlavorFlavor--Dependent Fluxes and SpectraDependent Fluxes and Spectra

Broad characteristicsBroad characteristics•• Duration a few secondsDuration a few seconds•• ⟨⟨EEνν⟩⟩ ~ ~ 1010−−20 MeV20 MeV•• ⟨⟨EEνν⟩⟩ increases with timeincreases with time•• Hierarchy of energiesHierarchy of energies

•• Approximate equipartitionApproximate equipartitionof energy between flavorsof energy between flavors

xee EEE ννν << xee EEE ννν <<

Livermore numerical modelLivermore numerical modelApJ 496 (1998) 216ApJ 496 (1998) 216

Prompt Prompt ννeedeleptonizationdeleptonizationburstburst

ννee

ννee

ννxx__

However, in traditionalHowever, in traditionalsimulations transport simulations transport of of ννµµ and and ννττ schematicschematic

•• Incomplete microphysicsIncomplete microphysics

•• Crude numerics to coupleCrude numerics to coupleneutrino transport withneutrino transport withhydro codehydro code


Literature Scan of FlavorLiterature Scan of Flavor--Dependent Neutrino SpectraDependent Neutrino Spectra

Keil, Janka & Raffelt, astroKeil, Janka & Raffelt, astro--ph/0208035ph/0208035


Supernova Neutrino Spectra FormationSupernova Neutrino Spectra Formation

Electron flavorElectron flavor (( ))ee,νν ee,νν

Free Free streamingstreaming−↔ν epne

−↔ν epne

+↔ν enpe+↔ν enpe

Thermal Equilibrium

Neutrino sphere (TNeutrino sphere (TNSNS))

Other flavorsOther flavors (( ))τµτµ νννν ,,, τµτµ νννν ,,,

DiffusionDiffusionThermal Equilibrium

Scattering AtmosphereScattering Atmosphere

ν↔ν NN ν↔ν NN

ν↔ν NN ν↔ν NN

νν↔ NNNN νν↔ NNNNνν↔−+ee νν↔−+ee

ee ν↔ν ee ν↔ν

Free Free streamingstreaming

µνµν↔νν ee µνµν↔νν ee

Transport sphereTransport sphereEnergy sphere (TEnergy sphere (TESES))

Raffelt (astroRaffelt (astro--ph/0105250), Keil, Raffelt & Janka (astroph/0105250), Keil, Raffelt & Janka (astro--ph/0208035)ph/0208035)

TTfluxflux~~ TTNSNS

TTfluxflux~0.6T~0.6TESES


FlavorFlavor--Dependent Neutrino Fluxes vs. Equation of StateDependent Neutrino Fluxes vs. Equation of State

Kitaura, Janka & Hillebrandt, “Explosions of OKitaura, Janka & Hillebrandt, “Explosions of O--NeNe--Mg cores, the CrabMg cores, the Crabsupernova, and subluminous Type IIsupernova, and subluminous Type II--P supernovae”, astroP supernovae”, astro--ph/0512065ph/0512065

Wolff & Hillebrandt nuclear EoS (stiff)

eνeν

τµτµ νν ,, ,

Lattimer & Swesty nuclear EoS (soft)

eνeν

τµτµ νν ,, ,


Microphysics for MuMicrophysics for Mu-- and Tauand Tau--Neutrino TransportNeutrino Transport

[1] Suzuki, Num. Astrophys. Japan 2 (1991) 267[1] Suzuki, Num. Astrophys. Japan 2 (1991) 267[2] Janka, W.Keil, Raffelt & Seckel, PRL 76 (1996) 2621 [astro[2] Janka, W.Keil, Raffelt & Seckel, PRL 76 (1996) 2621 [astro--ph/9507023]ph/9507023][3] Hannestad & Raffelt, ApJ 507 (1998) 339 [astro[3] Hannestad & Raffelt, ApJ 507 (1998) 339 [astro--ph/9711132]ph/9711132][4] Thompson, Burrows & Horvath, PRC 62 (2000) 035802 [astro[4] Thompson, Burrows & Horvath, PRC 62 (2000) 035802 [astro--ph/0003054]ph/0003054][6] Raffelt, ApJ 561 (2001) 890 [astro[6] Raffelt, ApJ 561 (2001) 890 [astro--ph/0105250] ph/0105250] [6] Buras, Janka, M.Keil, Raffelt & Rampp, ApJ (2003) [astro[6] Buras, Janka, M.Keil, Raffelt & Rampp, ApJ (2003) [astro--ph/0205006]ph/0205006][7] M.Keil, Raffelt & Janka, ApJ (2003) [astro[7] M.Keil, Raffelt & Janka, ApJ (2003) [astro--ph/0208035] ph/0208035]

Main opacityMain opacity

Energy exchangeEnergy exchange

Pair productionPair production

Traditional treatmentTraditional treatment Dominant processesDominant processes

N Nν + → + νN Nν + → + ν N Nν + → + νN Nν + → + ν

e eν + → + νe eν + → + νe eν + → + νe eν + → + ν

RecoilRecoil N Nν + → + νN Nν + → + ν

e e+ −+ → ν + νe e+ −+ → ν + νN N N N+ → + + ν + νN N N N+ → + + ν + ν

e eν + ν → ν + νe eν + ν → ν + ν

[2,6,7][2,6,7]

[1[1-- 4]4]

[6,7][6,7]


Flux and Spectra Modification by New ProcessesFlux and Spectra Modification by New Processes

Keil, Raffelt & Janka, ApJ (2003) [astroKeil, Raffelt & Janka, ApJ (2003) [astro--ph/0208035]ph/0208035]

TraditionalTraditional

+ Bremsstrahlung+ Bremsstrahlung


νν→ NNNN νν→ NNNN+ Bremsstrahlung+ Bremsstrahlung


+ Nucleon recoil+ Nucleon recoilν→ν NN ν→ν NN

νν→ NNNN νν→ NNNN+ Bremsstrahlung+ Bremsstrahlung


+ Neutrino pair+ Neutrino pair

+ Nucleon recoil+ Nucleon recoilν→ν NN ν→ν NN

νν→ NNNN νν→ NNNN

µµνν→νν ee µµνν→νν ee


What Are The Spectral Flux CharacteristicsWhat Are The Spectral Flux Characteristics??

TwoTwo--parameterparameterfitsfits(Normalization(Normalization isisthirdthird parameter)parameter)

Thermal spectrum,Thermal spectrum,i.e. Fermii.e. Fermi--Dirac shapeDirac shape((ηη fit)fit)

Quasi power lawQuasi power law((αα fit)fit)

The spectra are crudely thermal,The spectra are crudely thermal,but how to characterize in detail?but how to characterize in detail?

Commonly used global parametersCommonly used global parameters

•• Total luminosity Total luminosity LLνν•• Average energyAverage energy ⟨⟨EE⟩⟩•• General energy moments General energy moments ⟨⟨EEnn⟩⟩

•• “RMS energy”“RMS energy”

eνeν

eνeν

ττµµ νννν ,,, ττµµ νννν ,,,

E

EE

3

rms =E

EE

3

rms =

TE

2

e1

E)E(F +η−+

∝ TE

2

e1

E)E(F +η−+

∝

⎥⎦⎤

⎢⎣⎡ +α−∝ α

EE

)1(expE)E(F ⎥⎦⎤

⎢⎣⎡ +α−∝ α

EE

)1(expE)E(F


Alpha vs. Eta FitAlpha vs. Eta Fit

Starting with the width is reduStarting with the width is reduced in 10% stepsced in 10% steps⎟⎠⎞

⎜⎝⎛ −∝

EE

3expE)E(F 2 ⎟⎠⎞

⎜⎝⎛ −∝

EE

3expE)E(F 2

TE

2

e1

E)E(F +η−+

∝ TE

2

e1

E)E(F +η−+

∝⎥⎦⎤

⎢⎣⎡ +α−∝ α

EE

)1(expE)E(F ⎥⎦⎤

⎢⎣⎡ +α−∝ α

EE

)1(expE)E(F


Supernova 1987ASupernova 1987A


SN 1987A Rings (Hubble Space Telescope 4/1994)SN 1987A Rings (Hubble Space Telescope 4/1994)



SN 1987A Rings (Hubble Space Telescope 4/1994)SN 1987A Rings (Hubble Space Telescope 4/1994)

Supernova Remnant Supernova Remnant (SNR) 1987A (SNR) 1987A

Foreground StarForeground Star

Foreground StarForeground Star

500 Light-days500 Light-days

Ring system consists of Ring system consists of material ejected frommaterial ejected fromthe progenitor star,the progenitor star,illuminated by UV flash illuminated by UV flash from SN 1987Afrom SN 1987A


Distance Determination with Inner RingDistance Determination with Inner Ring

500

light

500

light

--day

sda

ys ∆∆tt11 ≈≈ 80 days80 days

∆∆tt22 ≈≈ 380 days380 days

≈≈ 50 kpc50 kpc ≈≈ 170,000 light170,000 light--yearsyears

ΘΘ = (1.242 = (1.242 ±± 0.022)0.022)””

Angular diameter Angular diameter ΘΘ++ = (1.716 = (1.716 ±± 0.022)0.022)””measured by HST on 24measured by HST on 24--88--19901990

∆∆tt11 and and ∆∆tt22 measured measured in UV by IUE satellite in UV by IUE satellite

Ni III] light curve SN 1987A ring, measured by IUENi III] light curve SN 1987A ring, measured by IUE[Sonneborn et al. ApJ 477 (1997) 848,[Sonneborn et al. ApJ 477 (1997) 848,fit by fit by Gould & Uza, ApJ 494 (1998) 118]Gould & Uza, ApJ 494 (1998) 118]

Distance to SN 1987ADistance to SN 1987A

51.2 ± 3.1 kpc Panagia et al., 51.2 ± 3.1 kpc Panagia et al., ApJ 380 (1991) L23 ApJ 380 (1991) L23

51.4 ± 1.2 kpc Panagia, 51.4 ± 1.2 kpc Panagia, IAU Symposium 190 (1999)IAU Symposium 190 (1999)

47.2 ± 0.9 kpc Gould & Uza, 47.2 ± 0.9 kpc Gould & Uza, ApJ 494 (1998) 118ApJ 494 (1998) 118


SN 1987A SN 1987A -- Explosion Hits Inner RingExplosion Hits Inner Ring


Neutrino Signal of SN 1987A in KamiokandeNeutrino Signal of SN 1987A in Kamiokande

SN 1987ASN 1987A

Background NoiseBackground Noise


Neutrino Signal of Supernova 1987ANeutrino Signal of Supernova 1987A

Within clock uncertainties,Within clock uncertainties,signals are contemporaneoussignals are contemporaneous

KamiokandeKamiokande--II (Japan)II (Japan)Water Cherenkov detectorWater Cherenkov detector2140 tons2140 tonsClock uncertainty Clock uncertainty ±±1 min1 min

IrvineIrvine--MichiganMichigan--Brookhaven (US)Brookhaven (US)Water Cherenkov detectorWater Cherenkov detector6800 tons6800 tonsClock uncertainty Clock uncertainty ±±50 ms50 ms

Baksan Scintillator TelescopeBaksan Scintillator Telescope(Soviet Union), 200 tons(Soviet Union), 200 tonsRandom event cluster ~ 0.7/dayRandom event cluster ~ 0.7/dayClock uncertainty Clock uncertainty +2/+2/--54 s54 s


SN 1987A Event No.9 in Kamiokande SN 1987A Event No.9 in Kamiokande

Kamiokande DetectorKamiokande Detector

Hirata et al., PRD 38 (1988) 448Hirata et al., PRD 38 (1988) 448


SN 1987A Signal in LSD (Mont Blanc)SN 1987A Signal in LSD (Mont Blanc) ??

LSD (Liquid Scintillator Detector)LSD (Liquid Scintillator Detector)in the Mont Blanc Tunnelin the Mont Blanc Tunnel(Oct. 1984 (Oct. 1984 -- March 1999)March 1999)Supernova monitor for our galaxySupernova monitor for our galaxy90 tons scintillator90 tons scintillator

200 tons iron (support structure)200 tons iron (support structure)

•• Observed a 5Observed a 5--event clusterevent cluster4.72 hours before IMB/Kam4.72 hours before IMB/Kam--IIII

•• Triggered autmatic SN alertTriggered autmatic SN alert•• Statistical fluctuation very unlikelyStatistical fluctuation very unlikely•• No significant signal in IMB/KamNo significant signal in IMB/Kam--IIII

at LSD timeat LSD time•• No significant LSD signal at IMB timeNo significant LSD signal at IMB time

•• Interpretation as “double bang”:Interpretation as “double bang”:Huge Huge ννee flux (~ 40 MeV) at LSD timeflux (~ 40 MeV) at LSD time

•• LSD signal caused by interactionsLSD signal caused by interactionsin iron of support structurein iron of support structure

•• Second bang ordinary multiSecond bang ordinary multi--flavorflavorsignalsignal

(Imshennik & Ryazhskaya,(Imshennik & Ryazhskaya,“A rotating collapsar and possible“A rotating collapsar and possibleinterpretation of the LSD neutrinointerpretation of the LSD neutrinosignal from SN 1987A”, signal from SN 1987A”, astroastro--ph/0401613) ph/0401613)


Early Lightcurve of SN 1987AEarly Lightcurve of SN 1987A

Adapted fromAdapted fromArnett et al.,Arnett et al.,ARAA 27 (1989)ARAA 27 (1989)

ExpectedExpectedvisual visual brightnessbrightnessevolutionevolution

ExpectedExpectedbolometric bolometric brightnessbrightnessevolutionevolution

Neutrinos severalNeutrinos severalhours before light hours before light


Dispersion between Neutrinos and PhotonsDispersion between Neutrinos and Photons

Neutrinos arrive a few hours earlier than photons Neutrinos arrive a few hours earlier than photons →→ Early warning (SNEWS)Early warning (SNEWS)SN 1987A: Transit time for photons and neutrinos equal to withinSN 1987A: Transit time for photons and neutrinos equal to within ~ 3h~ 3h

Equal within ~ 1 Equal within ~ 1 −− 4 4 ××1010−−33

Shapiro time delay for particles moving in a Shapiro time delay for particles moving in a gravitational potential gravitational potential

Longo, PRL 60:173,1988Longo, PRL 60:173,1988Krauss & Tremaine, PRL 60:176,1988Krauss & Tremaine, PRL 60:176,1988

•• Proves directly that neutrinos respond to gravity in the usual Proves directly that neutrinos respond to gravity in the usual waywaybecause for photons gravitational lensing already proves thisbecause for photons gravitational lensing already proves this pointpoint

•• Cosmological limits Cosmological limits ∆∆NNνν ≲≲ 1 much worse test of neutrino gravitation,1 much worse test of neutrino gravitation,i.e. SN 1987A proves that neutrinos in cosmology gravitate asi.e. SN 1987A proves that neutrinos in cosmology gravitate as they shouldthey should

•• Provides limits on parameters of certain nonProvides limits on parameters of certain non--GR theories of gravitationGR theories of gravitation•• Photons likely obscured for next galactic SN, so this result prPhotons likely obscured for next galactic SN, so this result probablyobably

unique to SN 1987A unique to SN 1987A

∫ months51dt)]t(r[U2t BAShapiro −≈−=∆ ∫ months51dt)]t(r[U2t BAShapiro −≈−=∆


Neutrino Cross Section in a Water TargetNeutrino Cross Section in a Water Target

Main reactions: dominates for Main reactions: dominates for SNSN

dominadominates for Suntes for Sun

CrossCrosssectionsection

perperwaterwater

moleculemolecule

++→+ν enpe++→+ν enpe

−+→+ν eFO 1616e

−+→+ν eFO 1616e

ν+→+ν −− ee ν+→+ν −− ee


Angular Distribution of SN 1987A NeutrinosAngular Distribution of SN 1987A Neutrinos

Main detection reactionMain detection reaction

is essentially isotropic for theis essentially isotropic for therelevant energies.relevant energies.

Expect only a fraction of anExpect only a fraction of anevent from forwardevent from forward--peakedpeakedreactionreaction

++→+ν enpe++→+ν enpe

ν+→+ν −− ee ν+→+ν −− ee


Trigger Efficiencies at the Detectors Trigger Efficiencies at the Detectors

Fiducial volumes for Fiducial volumes for SN 1987A detectionSN 1987A detection

Kamiokande IIKamiokande II2140 tons water2140 tons water(1.43(1.43××10103232 protons)protons)

IMBIMB6800 tons water6800 tons water(4.6(4.6××10103232 protons)protons)

BSTBST200 tons scintillator200 tons scintillator(1.88(1.88××10103131 protons)protons)


Energy Distribution of SN 1987A NeutrinosEnergy Distribution of SN 1987A Neutrinos

Kamiokande IIKamiokande II

IMBIMB


Interpreting SN 1987A NeutrinosInterpreting SN 1987A Neutrinos

Tota

l Bin

ding

Ene

rgy

Tota

l Bin

ding

Ene

rgy

95 % CLContours

Jegerlehner, Jegerlehner, Neubig & Raffelt,Neubig & Raffelt,PRD 54 (1996) 1194PRD 54 (1996) 1194

Assume thermalAssume thermalspectra andspectra andequipartition ofequipartition ofenergy between energy between the six degrees the six degrees of freedom of freedom ννee,, ννµµ,, ννττ and theirand theirantiparticlesantiparticlesSpectral Spectral ννee TemperatureTemperature

__

TheoryTheory


Cooling Time ScaleCooling Time Scale

Exponential coolingExponential coolingmodelmodelT = TT = T00 ee−−t/4t/4ττ

constant radiusconstant radiusL = LL = L00 ee−−t/t/ττ

Fit parameters areFit parameters areTT00, , ττ, radius,, radius,3 offset times3 offset timesfor detectorsfor detectors

(Loredo & Lamb,(Loredo & Lamb,astroastro--ph/0107260)ph/0107260)

Similar results forSimilar results formore sophisticatedmore sophisticatedcooling modelscooling models

95% CL95% CLcontourcontour

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III. Supernova Neutrinos -