Extreme Astrophysics

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Extreme Astrophysics
icecube.wisc.edu/halzen

• the sky _at_ gt 10 GeV photon energy
• lt 10-14 cm wavelength
• gt 108 TeV particles exist
• they should not
• more/better data
• arrays of air Cherenkov telescopes
• 104 km2 air shower arrays
• km3 neutrino detectors

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Energy (eV)
1 TeV
Radio
CMB
Visibe
GeV g-rays
Flux
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With 103 TeV energy, photons do not reach us from
the edge of our galaxy because of their small
mean free path in the microwave background.

• ?g gCMB ?????e e-

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Interaction length of protons in microwave
backgroundp gCMB p n
?????lgp (? nCMB s? ????? ) -1
_at_ 10 Mpc
pgCMB
GZK cutoff energy gt 5 107 TeV
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Energy (eV)
n
/ / / / / / / / / / / / / / / / /
CMB
Radio
Visible
TeV sources!
Flux
cosmic rays
GeV g-rays
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Multi-Messenger Astronomy

• protons, g-rays, neutrinos, gravitational waves
  as
• probes of the high-energy Universe

protons directions scrambled by magnetic fields

1.

• g-rays straight-line propagation but
• reprocessed in the sources, extragalactic
• backgrounds absorb Eg gt TeV

2.
3.

• neutrinos straight-line propagation,
• unabsorbed, but difficult to
  detect

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cosmic rays
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Galactic and Extragalactic Cosmic Rays
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the highest energies
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Acceleration to 1021 eV ?
102 Joules 0.01 MGUT

• dense regions with exceptional
• gravitational force creating relativistic
• flows of charged particles, e.g.
• dense cores of exploding stars
• supermassive black holes
• merging galaxies

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Active Galaxy
Radiation Field Ask Astronomers

• energy in protons
• energy in electrons
• photon target observed
• in lines
• gtgt few events per year km2

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Gamma Ray Bursts
Fireball Rapidly expanding collimated jet of
photons, electrons and positrons becoming
optically thin during expansion
Shocks external collisions with interstellar
material (e.g. remnant guaranteed TeV
neutrinos!!!) or internal collisions when slower
material is overtaken by faster in the fireball.
Protons and photons coexist in the fireball
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Cosmic Accelerators
E G cBR
R GM/c2
magnetic field
energy
E GBM
mass
boost factor
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E G?B M
E gt 1019 eV ?

• quasars G _at_ 1 B _at_ 103G M _at_?109
  Msun
• blasars G 10
• neutron stars G _at_ 1 B _at_ 1012G M _at_ Msun
• black holes
• .
• .
• grb G 102

gt
gt
emit highest energy gs!
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1024 eV 1015 GeV MGUT
_
are cosmic rays the decay product of

• topological defects ?
• (vibrating string, annihilating monopoles)
• heavy relics ?

Top. Def. X,Y W,Z quark leptons

• top-down spectrum
• hierarchy n gtgt g gtgt p

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Georges Lemaitre believed that cosmic rays where
primordial radiation from the Big Bang
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the Earths atmosphere as part of our detector
Cherenkov radiation
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Cosmic Rays Observations

• Cosmic Rays are subatomic particles and radiation
  of extra-terrestrial origin.
• First discovered in 1912 by German scientist
  Victor Hess, measuring radiation levels aboard a
  balloon at up to 17,500 feet (without oxygen!)
• Hess found increased radiation levels at higher
  altitudes named them Cosmic Radiation

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Ground Array and Air Fluorescence Detectors
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HiRes in Utah Desert
mirror
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Mirror and Camera
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Typical HiRes Stereo Events

• HiRes 2

• HiRes 1

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Two SpectraHiRes Mono and Flys Eye Stereo

• HiRes-1 6/97-2/03
• HiRes-2 12/99-9/01
• Excellent agreement between HiRes I and II.
• HiRes Stereo
• soon!

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AGASA _at_gt? !
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Auger array
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Ground Arrays
Auger

• Measures number of shower
• particles at ground level...

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cosmic photons associated with cosmic rays
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Galactic and Extragalactic Cosmic Rays
1 event km-2 yr-1
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gtgtgt energy in extra-galactic cosmic rays
3x10-19 erg/cm3 or 1044 erg/yr per (Mpc)3 for
1010 years
3x1039 erg/s per galaxy 3x1044 erg/s per active
galaxy 2x1052 erg per gamma ray burst gtgtgt
energy in cosmic rays equal to the
energy in light !
1 TeV 1.6 erg
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Neutrino Beams Heaven Earth
NEUTRINO BEAMS HEAVEN EARTH
Black Hole
Radiation Enveloping Black Hole
p g -gt n p cosmic ray neutrino
-gt p p0 cosmic ray gamma
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Neutrino Beams Heaven Earth
g n
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MAGIC A next step
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HESS RX J1713 Spectrum
18 h 2003 data
Resolution 10 arcmin First resolved TeV image
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Supernova Beam Dump
RX J1713-3946
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RX J1713 Spectrum

• In favor of p0
• no cut-off in the
• HE tail of HESS
• spectrum
• signal from the
• direction of
• molecular clouds

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Neutrino Beams Heaven Earth
g n
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g-rays from p0 decay discovered ?

• ? En Nn (En) ? ? Eg Ng (Eg)

1 lt ? lt
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accelerator beam dump (hidden source)
transparent source p0 p p-
n flux predicted observed g-ray
flux 20 per km2 RX J1713-3946
per year (galactic
center)
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TeV B L A Z A R 1ES 1959650 a
posteriori coincidence
H. Krawczynski et al, 2004ApJ,601 151K
Multiwavelength Observations of Strong Flares
from the TeV Blazar 1ES 1959650
TeV Flux (Crab)
10 keV Flux (keV-1 cm-2 s-1)
orphan flare
PRELIMINARY
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Sensitivity of Gamma ray telescopes
Sensitivity to neutrinos
8 9 10 11 12
13 14 15 16
log(E/eV)
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cosmic neutrinos associated with cosmic rays
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Requires Kilometer-Scale Neutrino Detectors
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detector
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ANTARES Layout
ANTARES
14.5 m
350 m
Junction box
100 m
40 km to shore
60-75 m
Readout cables
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Northern hemisphere detectors
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North
AMANDA
South Pole
Dome
1500 m
Amundsen-Scott South Pole station
2000 m
not to scale
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AMANDA II
t i me

• up-going muon
• 61 modules hit

gt 7 neutrinos/day on-line
Size Number of Photons
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IceCube optical sensor
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AMANDA Event SignatureMuon
CC muon neutrino interaction ? track
nm N ? m X
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Skyplot Amanda-II, 2000
697 events below horizon
above horizon mostly fake events
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1968 OSO-3 (Kraushaar et al. 1972)
sources seen in next mission! SAS-2 100 cm2

• effective area 4 cm2
• 600 photons

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AMANDA skyplot 2000-2003 optimized for best
sensitivity to E-3 E-2 sources
3369 events below horizon
Preliminary
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Neutrinos Associated With the Source of the
Cosmic Rays?
neutrino flux
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AMANDA skyplot 2000-2003 optimized for best
sensitivity to E-3 E-2 sources
3369 events below horizon
Preliminary
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AMANDA proof of concept
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Atmospheric Neutrinos
Cosmic Ray
p
??
e
??
?e
??
15 Km
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Optimized 2002 analysis
zenith distribution
10 events per day (as I speak!) 10,000 in 00-05
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size vs threshold
300 m
1500 m
50 m
2500 m
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• IceCube 01/05
• drilling ?
• 60 modules ?

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Drill modules at McMurdo
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IceTop IceCube coincident muon
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IceCube particle physics withone million
atmospheric neutrinos

• Astronomy new window on the Universe
• Physics
• measurement of the high-energy neutrino cross
  section
• TeV-scale gravity, quantum decoherence
• physics beyond 3-flavor oscillations
• test special and general relativity with new
  precision
• search for magnetic monopoles
• search for neutralino (or other) dark matter
• search for topological defects and cosmological
  remnants
• search for magnetic monopoles

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µ-event in IceCube300 atmospheric neutrinos per
day
AMANDA II
IceCube Larger Telescope Superior Detector
1 km
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nt t
PeV t(300m)
t decays
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IceCube

• tests
• equivalence
• principle
• and
• Lorentz
• invariance
• general
• relativity
• will not last
• 200 years
• M. Turner

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GZK event in AMANDA and IceCube
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conclusions

• techniques of particle physics reborn to
• do astronomy

• may still do particle physics ( n mass ! )

• cosmic ray puzzle will be solved less than
• 100 years after their discovery