Lepton - Photon 01 Francis Halzen

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Lepton - Photon 01Francis Halzen

• the sky gt 10 GeV photon energy
• lt 10-14 cm wavelength
• gt 108 TeV particles exist
• Flys Eye/Hires
• 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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n
/ / / / / / / / / / / / / / / / /
TeV sources!
cosmic rays
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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 g??? ?????e e-

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fluorescence from atmospheric nitrogen
_
cosmic ray
_
?o??????????? ?????????????
fluorescent light
electromagnetic shower
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Acceleration to 1021eV? 102
Joules 0.01 MGUT

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

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Cosmic Accelerators
E GcBR
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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Profile of Gamma Ray Bursts

• Total energy one solar mass
• Photon energy 0.1 MeV to TeV
• Duration 0.1 secs -- 20 min
• Several per day
• Brightest object in the sky
• Complicated temporal structure
• no typical burst profile

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A few more results

• Gamma Ray Bursts (GRBs)
• Observation of single 3 s excess (GRB 970417a)
  within 1997 BATSE trigger.
• Flux limit for unidentified TeV point sources
• For E spectrum

Flux (gt1 TeV) lt 2 30 x 10-7 cm-2 s-1 _at_ 90
AMANDA II will probe this flux for
n/g 1
However, g spectrum probably softer due to
reprocessing (core) and absorption in photon BG
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Particles gt 1020 eV ?

• not protons
• cannot reach us from cosmic accelerators
• lint lt 50 Mpc
• no diffusion in magnetic fields
• doublets, triplet
• not photons
• g Bearth e e- not seen
• showers not muon-poor
• not neutrinos
• snp ? 10-5 spp ????? no air showers

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Interaction length of protons in microwave
backgroundp gCMB p .
?????lgp (?nCMB s? ????? ) -1 _at_
10 Mpc
pgCMB
GZK cutoff
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Forthcoming AGASA Results

• The highest energy cosmic rays do come from point
  sources 5 sigma correlation between directions
  of pairs of particles. Birth of proton astronomy!
  
• Are the highest energy cosmic rays Fe?
  
• GKZ cutoff at 2 1020 eV ?

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Particles gt 1020 eV ?
new astrophysics?

• not protons
• cannot reach us from cosmic accelerators
• lint lt 50 Mpc
• no diffusion in magnetic fields
• doublets, triplet
• not photons
• g Bearth e e- not seen
• showers not muon-poor
• not neutrinos
• snp ? 10-5 spp ?? no air showers

trouble for top-down scenarios
sn p _at_ spp with TeV - gravity unitarity?
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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
?? gtgt p
?? ?? g

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

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black hole
radiation enveloping black hole
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cosmic ray puzzle
neutrinos
protons
TeV g - rays
1 km3 high energy detectors
104 km2 air shower arrays

• atmospheric Cherenkov
• space-based

• AMANDA / Ice Cube
• Antares, Nestor,
• NEMO

• Veritas, Hess, Magic
• GLAST

• Hi Res, Auger,
• Airwatch,
• OWL, TA

e.g.

• particle physics
• and cosmology
• dark matter search
• discovery

• short-wavelength
• study of supernova
• remnants and galaxies

also
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Array gt Very large effective area (105 m2)
gt 3-dim shower reconstruction gt Dramatic
improvements in - Energy Resolution
- Background Rejection
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STACEE
Solar Tower Atmospheric Cherenkov Effect
Experiment
Gamma-ray Astrophysics between 50-500 GeV
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ne e W m? nm 6400 TeV
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nt t
PeV t(300m)
t decays
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Why is Searching for ns from GRBs of Interest?

• Search for vacuum oscillations (n??????nt)
• Dm2 ?? 10-17 eV2
• Test weak equivalence principle 10-6
• Test 10-16

gt
Cphoton - Cn Cn
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Lepton - Photon 01Francis Halzen

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

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n
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TeV sources!
cosmic rays