1. Supernova Neutrinos Physics Opportunities with
Crab Nebula
Neutrinos in Cosmology, Astro, Particle & Nuclear Physics
16-24 September 2009, Erice, Sicily
Physics Opportunities with
Supernova Neutrinos
Georg Raffelt, Max-Planck-Institut für Physik, München

2. Stellar Collapse and Supernova Explosion
Onion structure
Main-sequence star
Hydrogen Burning
Collapse (implosion)
Helium-burning star
Helium
Burning
Hydrogen
Degenerate iron core:
r  109 g cm-3
T  K
MFe  1.5 Msun
RFe  8000 km

3. Stellar Collapse and Supernova Explosion
Newborn Neutron Star
~ 50 km
Proto-Neutron Star
r  rnuc = 3  g cm-3
T  30 MeV
Collapse (implosion)
Neutrino
Cooling

4. Stellar Collapse and Supernova Explosion
Newborn Neutron Star
~ 50 km
Proto-Neutron Star
r  rnuc = 3  g cm-3
T  30 MeV
Neutrino
Cooling
Gravitational binding energy
Eb  3  1053 erg  17% MSUN c2
This shows up as
99% Neutrinos
1% Kinetic energy of explosion
(1% of this into cosmic rays)
0.01% Photons, outshine host galaxy
Neutrino luminosity
Ln  3  1053 erg / 3 sec
 3  1019 LSUN
While it lasts, outshines the entire
visible universe

5. Diffuse Supernova Neutrino Background (DSNB)
Supernova rate approximately
1 SN / 1010 LSun,B / 100 years
Lsun,B = 0.54 Lsun = 2  1033 erg/s
En ~ 3  1053 erg per core-collapse
Core-collapse neutrino luminosity of
typical galaxy comparable to photon
luminosity (from nuclear burning)
Core-collapse rate somewhat larger
in the past. Estimated present-day
flux ~ 10 cm-2 s-1
Pushing the boundaries of neutrino
astronomy to cosmological distances
Beacom & Vagins, hep-ph/
[Phys. Rev. Lett., 93:171101, 2004]

6. Realistic DSNB Estimate
Horiuchi, Beacom & Dwek, arXiv: v3

7. Sanduleak -69 202 Supernova 1987A 23 February 1987 Tarantula Nebula
Large Magellanic Cloud
Distance 50 kpc
( light years)

8. Neutrino Signal of Supernova 1987A
Kamiokande-II (Japan)
Water Cherenkov detector
2140 tons
Clock uncertainty 1 min
Irvine-Michigan-Brookhaven (US)
Water Cherenkov detector
6800 tons
Clock uncertainty 50 ms
Baksan Scintillator Telescope
(Soviet Union), 200 tons
Random event cluster ~ 0.7/day
Clock uncertainty +2/-54 s
Within clock uncertainties,
signals are contemporaneous

9. 2002 Physics Nobel Prize for Neutrino Astronomy
Ray Davis Jr.
( )
Masatoshi Koshiba
(*1926)
“for pioneering contributions to astrophysics, in
particular for the detection of cosmic neutrinos”

10. Gamow & Schoenberg, Phys. Rev. 58:1117 (1940)

11. Large Detectors for Supernova Neutrinos
MiniBooNE
(200)
LVD (400)
Borexino (100)
Baksan
(100)
Super-Kamiokande (104)
KamLAND (400)
In brackets events
for a “fiducial SN”
at distance 10 kpc
IceCube (106)

12. Current and Near-Future SN Neutrino Detectors
Type
Location
Mass
(kton)
Events
@ 8 kpc
Status
Super-K
Water
Japan 32
8000
Running (SK IV)
LVD
Scintillator
Italy 1
300
Running
KamLAND
Borexino
0.3
100
IceCube
Ice
South Pole
0.4/PMT
1 million
Baksan
Russia
0.33 50
Mini-BOONE
USA
0.7
200
HALO
Lead
Canada
0.076 85
Under construction
Icarus
Liquid argon
0.6
230
Almost ready
NOnA 15
3000
Construction started
SNO+
Funded
Adapted from Kate Scholberg, TAUP 2009

13. Super-Kamiokande Neutrino Detector

14. Simulated Supernova Burst in Super-Kamiokande
Movie by C. Little, including work by S. Farrell & B. Reed,
(Kate Scholberg’s group at Duke University)

15. IceCube Neutrino Telescope at the South Pole
1 km3 antarctic ice, instrumented
with 4800 photomultipliers
59 of 80 strings installed (2009)
Completion until 2011 foreseen

16. IceCube as a Supernova Neutrino Detector
Each optical module (OM) picks up
Cherenkov light from its neighborhood.
SN appears as “correlated noise”.
About 300
Cherenkov
photons
per OM
from a SN
at 10 kpc
Noise
~280 Hz
Total of
4800 OMs
foreseen
in IceCube
IceCube SN signal at 10 kpc, based
on a numerical Livermore model
[Dighe, Keil & Raffelt, hep-ph/ ]
Method first discussed by
Pryor, Roos & Webster,
ApJ 329:355 (1988)
Halzen, Jacobsen & Zas
astro-ph/

17. Galactic Supernova Distance Distribution
Mirizzi,
Raffelt,
Serpico,
astro-ph
Average distance 10.7 kpc, rms dispersion 4.9 kpc
(11.9 kpc and 6.0 kpc for SN Ia distribution)

18. The Red Supergiant Betelgeuse (Alpha Orionis)
First resolved
image of a star
other than Sun
Distance
(Hipparcos)
130 pc (425 lyr)
If Betelgeuse goes Supernova:
6 107 neutrino events in Super-Kamiokande
2.4 103 neutron events per day from Silicon-burning phase
(few days warning!), need neutron tagging
[Odrzywolek, Misiaszek & Kutschera, astro-ph/ ]

19. Local Group of Galaxies
With megatonne class (30 x SK)
60 events from Andromeda
Current best neutrino detectors
sensitive out to few 100 kpc

20. Next Generation Large-Scale Detector Concepts
5-100 kton
liquid Argon
DUSEL
LBNE
100 kton scale
scintillator
Hyper-K
Memphys
LENA
HanoHano
Megaton-scale
water Cherenkov

21. Reaching Beyond the Milky Way: Five-Megaton Detector
Modular 5-Mt underwater detector
for proton decay, long-baseline oscillation experiments,
atmospheric neutrinos, and low-energy burst detection

22. Galactic Supernova Rate
Looking forward
Galactic Supernova Rate

23. Core-Collapse SN Rate in the Milky Way
SN statistics in
external galaxies
Core-collapse SNe per century 1 2 3 4 5 6 7 8 9 10
van den Bergh & McClure (1994)
Cappellaro & Turatto (2000)
Gamma rays from
26Al (Milky Way)
Diehl et al. (2006)
Historical galactic
SNe (all types)
Strom (1994)
Tammann et al. (1994)
No galactic neutrino
burst since 1980
90 % CL (25 y obserservation)
Alekseev et al. (1993)
References: van den Bergh & McClure, ApJ 425 (1994) 205. Cappellaro & Turatto, astro-ph/ Diehl et al., Nature 439 (2006) 45. Strom, Astron. Astrophys. 288 (1994) L1. Tammann et al., ApJ 92 (1994) 487. Alekseev et al., JETP 77 (1993) 339 and my update.

24. Observed SNe in the Local Universe (Past Decade)
Statistical
Prediction
Kistler,Yüksel, Ando, Beacom & Suzuki, arXiv:

25. High and Low Supernova Rates in Nearby Galaxies
M31 (Andromeda)
D = 780 kpc
NGC 6946
D = (5.5 ± 1) Mpc
Last Observed Supernova: 1885A
Observed Supernovae:
1917A, 1939C, 1948B, 1968D, 1969P,
1980K, 2002hh, 2004et, 2008S

26. SuperNova Early Warning System (SNEWS)
Supernova 1987A
Early Light Curve
Super-K
IceCube
Coincidence
Server
@ BNL
Alert
LVD
Others ?
Neutrino observation can alert astronomers
several hours in advance to a supernova.

27. Probing Supernova Physics
Looking forward
Probing Supernova Physics

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

29. Standing Accretion Shock Instability (SASI)
Mezzacappa et al.,

30. Luminosity Variation Detectable in Neutrinos?
Polar direction
Hemispheric average
Neutrino events in 10 ms bins for
SN (10 kpc) during accretion phase:
Super-K s ~ 10%
30 x Super-K 2 s ~ 2%
IceCube  s ~ 1%
Detecting the spectrum of luminosity
variations can
Detect SASI instability in neutrinos
Provide equation-of-state
information
Marek, Janka & Müller, arXiv:

31. Fourier Transform of Luminosity Variation
Approximate
level of
Poisson noise
in IceCube
for a SN at
10 kpc
Polar direction
Hemispheric
average
Detectability
to be studied
in more detail
(Lund, Marek,
Lunardini,
Janka, Raffelt,
Work in
progress)
Marek, Janka & Müller, arXiv:

32. Neutrino Mass and Resolution of Time Variations
Signal dispersion for Next Nearby SN
IceCube binning of data: 1.64 ms in each OM
Laboratory neutrino mass limit: 2.2 eV
Cosmological limit Smn < 0.6 eV, so individual mass limit 0.2 eV
KATRIN sensitivity roughly 0.2 eV
For SN signal interpretation of fast time variations, it is important to have
the cosmological limit and future KATRIN measurement/limit
Supernova neutrino aficionados
are new customers for KATRIN results!

33. Gravitational Waves from Core-Collapse Supernovae
Müller, Rampp, Buras, Janka, & Shoemaker,
“Towards gravitational wave signals from
realistic core collapse supernova models,”
astro-ph/
Asymmetric neutrino emission
Bounce
Convection
The gravitational-wave signal from convection
is a generic and dominating feature

34. Neutrino Emission Around Bounce Time
Different Mass
Neutrino Transport
Nuclear EoS
Prompt
Neutronization
Burst
Kachelriess,
Tomàs, Buras,
Janka, Marek
& Rampp,
astro-ph /

35. Millisecond Bounce Time Reconstruction
Super-Kamiokande
IceCube
Emission model adapted to
measured SN 1987A data
“Pessimistic distance” of 20 kpc
Determine bounce time to within
a few tens of milliseconds
Onset of neutrino
emission
10 kpc
Pagliaroli, Vissani, Coccia & Fulgione
arXiv:
Halzen & Raffelt
arXiv:

36. Do Neutrinos Gravitate?
Neutrinos arrive a few hours earlier than photons  Early warning (SNEWS)
SN 1987A: Transit time for photons and neutrinos equal to within ~ 3h
Shapiro time delay for particles moving in a
gravitational potential
Longo, PRL 60:173,1988
Krauss & Tremaine, PRL 60:176,1988
Equal within ~ 10-3
Proves directly that neutrinos respond to gravity in the usual way
because for photons gravitational lensing already proves this point
Cosmological limits DNn ≲ 1 much worse test of neutrino gravitation
Provides limits on parameters of certain non-GR theories of gravitation

37. Particle Physics Bounds
Looking forward
Particle Physics Bounds

38. The Energy-Loss Argument
Neutrino
sphere
SN 1987A neutrino signal
Neutrino
diffusion
Late-time signal most sensitive observable
Emission of very weakly interacting
particles would “steal” energy from the
neutrino burst and shorten it.
(Early neutrino burst powered by accretion,
not sensitive to volume energy loss.)
Volume emission
of novel particles

39. New Long-Term Cooling Calculations
Fischer et al. (Basel Group), arXiv:

40. Neutrino Flavor Oscillations
Looking forward
Neutrino Flavor Oscillations

41. Neutrino Emission Around Bounce Time
Different Mass
Neutrino Transport
Nuclear EoS
Prompt
Neutronization
Burst
Kachelriess,
Tomàs, Buras,
Janka, Marek
& Rampp,
astro-ph /

42. Flavor Dependence of Neutrino Emission
Fischer et al. (Basel Group), arXiv:

43. Flavor-Dependent Neutrino Fluxes vs. Equation of State
Wolff & Hillebrandt nuclear EoS (stiff)
Lattimer & Swesty nuclear EoS (soft)
Kitaura, Janka & Hillebrandt, “Explosions of O-Ne-Mg cores, the Crab
supernova, and subluminous Type II-P supernovae”, astro-ph/

44. Level-Crossing Diagram in a SN Envelope
Normal mass hierarchy
Inverted mass hierarchy
Dighe & Smirnov, Identifying the neutrino mass spectrum from a supernova
neutrino burst, astro-ph/

45. Spectra Emerging from a Supernova
Primary fluxes
for
After leaving the
supernova envelope,
the fluxes are
partially swapped
Normal
Inverted
sin2(2Q13)
≲ 10-5
≳ 10-3
Any
Mass ordering
sin2(Q12)
cos2(Q12)
Case A B C
Survival probability

46. Collective Effects in Neutrino Flavor Oscillations
Collapsed supernova core or accretion torus of
merging neutron stars:
Neutrino flux very dense: Up to 1035 cm-3
Neutrino-neutrino interaction energy
much larger than vacuum oscillation frequency
Large “matter effect” of neutrinos on each
other
Non-linear oscillation effects
Assume 80% anti-neutrinos
Vacuum oscillation frequency
w = 0.3 km-1
Neutrino-neutrino interaction
energy at nu sphere (r = 10 km)
m = 0.3105 km-1
Falls off approximately as r-4
(geometric flux dilution and nus
become more co-linear)

47. Collective SN Neutrino Oscillations since 2006
Two seminal papers in 2006 triggered a torrent of activities
Duan, Fuller, Qian, astro-ph/ , Duan et al. astro-ph/
Duan, Fuller, Carlson & Qian, astro-ph/ , , arXiv: ,
Duan, Fuller & Qian, arXiv: , ,
Duan, Fuller & Carlson, arXiv: Duan & Kneller, arXiv:
Hannestad, Raffelt, Sigl & Wong, astro-ph/ Balantekin & Pehlivan,
astro-ph/ Balantekin, Gava & Volpe, arXiv: Gava & Volpe,
arXiv: Gava, Kneller, Volpe & McLaughlin, arXiv:
Raffelt & Sigl, hep-ph/ Raffelt & Smirnov, arXiv: ,
Esteban-Pretel, Pastor, Tomàs, Raffelt & Sigl, arXiv: ,
Esteban-Pretel, Mirizzi, Pastor, Tomàs, Raffelt, Serpico & Sigl,
arXiv: Raffelt, arXiv: Fogli, Lisi, Marrone & Mirizzi,
arXiv: Fogli, Lisi, Marrone & Tamborra, arXiv: ,
Lunardini, Müller & Janka, arXiv: Dasgupta & Dighe,
arXiv: Dasgupta, Dighe & Mirizzi, arXiv: Dasgupta,
Dighe, Mirizzi & Raffelt, arXiv: , Dasgupta, Dighe,
Raffelt & Smirnov, arXiv: Sawyer, arXiv:
Chakraborty, Choubey, Dasgupta & Kar, arXiv: Blennow, Mirizzi &
Serpico, arXiv: Wei Liao, arXiv: ,

48. General Equations of Motion
Vacuum oscillations
M is neutrino mass matrix
Note opposite sign between
neutrinos and antineutrinos
Usual matter effect with
Nonlinear nu-nu effects are important
when nu-nu interaction energy exceeds
typical vacuum oscillation frequency
(Do not compare with matter effect!)

49. Oscillations of Neutrinos plus Antineutrinos in a Box
Equal and densities, single energy E, with ≫
Equal
self terms
Opposite vacuum
oscillations
“Pendulum in flavor space”
Inverted mass hierarchy
 Inverted pendulum
 Unstable even for small mixing angle
Normal mass hierarchy
 Small-amplitude oscillations

50. Flavor Conversion in Toy Supernova
Assume 80% anti-neutrinos
Vacuum oscillation frequency
w = 0.3 km-1
Neutrino-neutrino interaction
energy at nu sphere (r = 10 km)
m = 0.3105 km-1
Falls off approximately as r-4
(geometric flux dilution and nus
become more co-linear)
Pendular
Oscillations
Decline of oscillation amplitude
explained in pendulum analogy
by inreasing moment of inertia
(Hannestad, Raffelt, Sigl & Wong
astro-ph/ )

51. Spectral Split for Accretion Phase Example
Initial fluxes
at nu sphere
After
collective
trans-
formation
For explanation see
Raffelt & Smirnov
arXiv:
Duan, Fuller,
Carlson & Qian
arXiv:
Fogli et al., arXiv: ,

52. Multiple Spectral Splits (Cooling-Phase Example)
Inverted
Hierarchy
Normal
Hierarchy
Dasgupta, Dighe, Raffelt & Smirnov, arXiv:

53. Multiple Spectral Splits in the w Variable
Given is the flux spectrum f(E) for
each flavor
Use w = Dm2/2E to label modes
Label anti-neutrinos with -w
Define “spectrum” as
Neutrinos
Antineutrinos
Swaps develop around every
“positive” spectral crossing
Each swap flanked by two splits
antineutrinos
neutrinos
Dasgupta, Dighe, Raffelt & Smirnov,
arXiv:

54. Flavor Pendulum Single “positive” crossing
(potential energy at a maximum)
Single “negative” crossing
(potential energy at a minimum)
Dasgupta, Dighe, Raffelt & Smirnov, arXiv:
For movies see

55. Decreasing Neutrino Density
Certain initial neutrino density
Four times smaller
initial neutrino density
Dasgupta, Dighe, Raffelt & Smirnov, arXiv:
For movies see

56. Supernova Cooling-Phase Example
Normal Hierarchy
Inverted Hierarchy
Dasgupta, Dighe, Raffelt & Smirnov, arXiv:
For movies see

57. Multiple Spectral Splits (Cooling-Phase Example)
Inverted
Hierarchy
Normal
Hierarchy
Dasgupta, Dighe, Raffelt & Smirnov, arXiv:

58. Questions and Opportunities
Self-induced collective oscillations occur even
for very small 13-mixing (instability!)
Observation of spectral split or swap indication
can provide signature for mass hierarchy
and nontrivial neutrino propagation dynamics
Do matter-density fluctuations have any
realistic impact?
Theoretical understanding and role of
“multi-angle effects” largely missing

59. Spectral Split (Accretion-Phase Example)
Initial fluxes
at neutrino
sphere
After
collective
trans-
formation
For explanation see
Raffelt & Smirnov
arXiv:
Duan, Fuller,
Carlson & Qian
arXiv:
Fogli, Lisi, Marrone & Mirizzi, arXiv:

60. Distinguishing Mixing Scenarios
Hierarchy
sin2 Q13
Survival Probability
Earth
effects
E < Esplit
E > Esplit
Normal
≳ 10-3
cos2 Q12
Inverted
sin2 Q12
Normal
≲ 10-5
sin2 Q12
Inverted -
Assuming “standard” flux spectra leading to a single split
Probably generic for accretion phase
Adapted from Dighe, arXiv:

61. Mass Hierarchy at Extremely Small Theta-13
Using Earth matter effects to diagnose transformations
Ratio of spectra in
two water Cherenkov
detectors (0.4 Mton),
one shadowed by the
Earth, the other not
Dasgupta, Dighe & Mirizzi, arXiv:

62. Diagnosing Collective Transformations
Assuming the mass ordering is measured to be inverted in the lab,
the presence or absence of Earth effects distinguishes between
the presence or not of collective transformations
Collective Transformations No
Yes
Hierarchy
sin2 Q13
survival
probability
Earth
effects
survival
probability
Earth
effects
Normal
≳ 10-3
cos2 Q12
Yes
cos2 Q12
Yes
Inverted No
Normal
≲ 10-5
cos2 Q12
Yes
Inverted No

63. What exactly will be learnt from the neutrinos
Looking forward
What exactly will be learnt from the neutrinos
of the next nearby SN depends a lot on what
exactly is observed

64. SN neutrinos are powerful astrophysical
Looking forward
SN neutrinos are powerful astrophysical
and particle-physics messengers