Astroparticle Physics Key Issues

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Astroparticle PhysicsKey Issues

• Jan Kuijpers
• Dep. of Astrophysics/ HEFIN
• University of Nijmegen

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Cosmic Ray Energy Spectrum
_10-1 Flux (m2 sr s GeV)-1 _10-25
__(1 per m2-sec)
E-2.7 E-3
Knee __(1 per m2-year)
Flux x E2.75
e- up to 1 TeV, only 1
Ankle (1 per km2-year)__
LHC
Swordy
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Energy (eV) 1020

1 Energy (GeV/n) 107
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• Cosmic Rays
• Direct detection
• Nuclei, power-law
• Gamma-rays up to TeV (AGN, pulsars)
• Neutrinos (solar, SN1987a)
• Indirect detection from radiation optically thin
• synchrotron, inverse Compton, bremsstrahlung
• Electrons power-law 2/2.7/-3 over many decades
  in extragalactic radio galaxies. Also in
  extragal. GRBs, galactic SNRs, X-ray binaries,
  jets.
• Protons (X-ray and MeV galactic)

Main question 1 UNIVERSAL ACCELERATION PROCESS?
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Particle acceleration processes

• Shock waves (Bell,..1977 Fermi 1954)

?
De Hoffmann- Teller frame
?
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2
u2
u1
?
SNRs vsfew 104 km/s GRBs ?300 Jets Radio
galaxies X-ray binaries
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Magnetars Pulsars Stellar mass black holes

• 109 G_
• B
• 10-9 G_

Emax ZeBL?
Flare stars
Massive black holes
1 AU 1 pc 1 kpc 1 Mpc
Size
(km) 10 10
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• More questions

2 TeV gamma rays from electrons or protons?
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Case study L3Cosmics search for TeV photons
from GRBs

• Significance of muon excess

GRB 990903
from 64 EGRET unidentified 30 MeV/30 GeV GRSs
muons per square degree per sec
galactic coordin.
Van den Akker 2004 PhD Thesis KUN
not corrected for detector accept.
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3 Origin e? plasma?

• Linear acceleration of primary electrons in
  unipolar inductor (neutron stars, accretion
  discs, black hole collapse torus) and
  subsequent pair creation in strong B or photon
  background.

C
Rotation axis
Pair plasma production in circuit C
C
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1000 ? 950
Case study Coherent emission from particle beams
varying magnetic wiggler
E (V/m)
t (10-5 sec)
f (10-10 Hz)
P (1013 W)
Radio pulsars as Free Electron Lasers
Fung Kuijpers, 2004, AA subm.
t (10-5 sec)
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4 Origin of magnetic field?

• Dynamo

Poynting flux dominated Magnetized wind Jets
accretion disk compact object
5 Origin energy fireball?

• - Magnetic reconnection
• Plasma turbulence
• Stochastic acceleration

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Case study Coupling gravitational waves mhd
waves
GWx
GW
z
z
x
y
Alfven wave
Magnetosonic wave
S F G
A G
Moortgat Kuijpers 2003 AA 402, 905 2004 Phys
Rev D, subm.
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• 6. Is there a high energy CR cut-off?

Photopair production
Photopion production
GZK cutoff
Cronin 2004
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7. Origin of highest energy CRs?
Conflicting observ. Inconclusive statistics
Cronin 2004
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Case study L3Cosmics composition forward
cross-section
muons
muon multiplicity
Comparison to Monte Carlo CORSIKA
Wilkens, 2003, PhD Thesis KUN
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Case study L3Cosmics muon spectrum at sea level
Accurate absolute spectrum
Charge ratio
Petersen, 2002 PhD Thesis, KUN
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Air showers
Gamma ray ----- Fe _______ Protons ______
LOFAR cornerstone study of CRs and their sources
Cronin 2004
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Outreach opportunities NAHSA HiSPARC
- LOFAR
High schools cosmic rays detector
construction, observations, analysis
Timmermans et al, 2004, KUN
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• Key questions in astroparticle physics
• ORIGINS CRs (HADRONSLEPTONS)
• SNRs, BHs, NSs, DARK MATTER, DARK ENERGY
• UNIVERSAL ACCELERATION PROCESS?
  
• TeV GAMMA RAYS FROM ELECTRONS OR PROTONS?
• ORIGIN e? PLASMA?
• ORIGIN OF MAGNETIC FIELD?
• ENERGY PARTITIONING
• IS THERE A HIGH ENERGY CR CUT-OFF?
• QUEST FOR HIGHEST ENERGY CRs AND SOURCES

2 communities astroparticle detectorsLOFAR
ANTARES