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Astroparticle Physics Key Issues. Jan Kuijpers Dep. of Astrophysics/ HEFIN University of Nijmegen. Cosmic Ray Energy Spectrum. _10 -1 Flux (m 2 sr s GeV) -1 _10 -25. __(1 per m 2 -sec). E -2.7 E -3. Knee __(1 per m 2 -year). Flux x E 2.75.
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Astroparticle PhysicsKey Issues Jan Kuijpers Dep. of Astrophysics/ HEFIN University of Nijmegen Astroparticle Physics
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 | | 109 Energy (eV) 1020 | | 1 Energy (GeV/n) 107 Astroparticle Physics
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? Astroparticle Physics
Particle acceleration processes De Hoffmann- Teller frame 1 2 • Shock waves (Bell,..1977; Fermi 1954): u2 u1 SNRs: vs~few 104 km/s GRBs: ~300 Jets: Radio galaxies X-ray binaries Astroparticle Physics
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 Astroparticle Physics
2: TeV gamma rays from electrons or protons? More questions: Astroparticle Physics
Case study: L3+Cosmics: 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. Astroparticle Physics
3: Origin e plasma? C Rotation axis 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. Pair plasma production in circuit C C Astroparticle Physics
Case study: Coherent emission from particle beams 1000 950 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, A&A subm. t (10-5 sec) Astroparticle Physics
4: Origin of magnetic field? Poynting flux dominated Magnetized wind Jets Dynamo accretion disk compact object 5: Origin energy fireball? • - Magnetic reconnection • Plasma turbulence • Stochastic acceleration Astroparticle Physics
Case study: Coupling gravitational waves – mhd waves GWx GW+ z z x y Alfven wave Magnetosonic wave S F G A G Astroparticle Physics Moortgat & Kuijpers 2003 A&A 402, 905 ; 2004 Phys Rev D, subm.
6. Is there a high energy CR cut-off? Photopair production Photopion production | GZK cutoff Cronin 2004 Astroparticle Physics
7. Origin of highest energy CRs? Conflicting observ. Inconclusive statistics Cronin 2004 Astroparticle Physics
Case study: L3+Cosmics: composition – forward cross-section muons muon mul;tiplicity Comparison to Monte Carlo CORSIKA Wilkens, 2003, PhD Thesis KUN Astroparticle Physics
Case study: L3+Cosmics: muon spectrum at sea level Accurate absolute spectrum Charge ratio Petersen, 2002 PhD Thesis, KUN Astroparticle Physics
Air showers Gamma ray: ----- Fe: _______ Protons: ______ LOFAR cornerstone: study of CRs and their sources Astroparticle Physics Cronin 2004
Outreach opportunities: NAHSA – HiSPARC - LOFAR High schools & cosmic rays: detector construction, observations, analysis Timmermans et al, 2004, KUN Astroparticle Physics
Key questions in astroparticle physics: • ORIGINS CRs (HADRONS+LEPTONS): • 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 Astroparticle Physics