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AGASA update

AGASA update. M. Teshima ICRR, U of Tokyo @ CfCP mini workshop Oct 4 2002. AGASA Akeno Giant Air Shower Array. 111 Electron Det. 27 Muon Det. 0 4km. Exposures in various experiments. AGASA: Ground Array HiRes: Air Fluorescence. Energy Determination. Local density at 600m

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AGASA update

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  1. AGASA update M. Teshima ICRR, U of Tokyo @ CfCP mini workshop Oct 4 2002

  2. AGASAAkeno Giant Air Shower Array 111 Electron Det. 27 Muon Det. 0 4km

  3. Exposures in various experiments AGASA: Ground Array HiRes: Air Fluorescence

  4. EnergyDetermination • Local density at 600m • Good energy estimator by M.Hillas E=2x1020eV, Emin = 1.6x1020eV

  5. S(600) vs Nch Attenuation curve 1018eV Proton Atmospheric depth

  6. Proton S600 Intrinsic fluctuation for proton and iron Iron

  7. Energy Determination in AGASA Please read astro-ph/0209422

  8. Detector Calibration in AGASA experiment Detector Position Gain as a function of time (11years data) Survey from Airplane ΔＸ，ΔＹ＝0.1m, ΔＺ＝0.3m Cable delay (optic fiber cable) Accuracy of 100ps by measuring the round trip time in each run Linearity as a function of time (11years data) Detector Gain by muons in each run

  9. Detector Response vertical θ = 60deg Detector Simulation (GEANT) Detector Housing (Fe 0.4mm) Detector Box (Fe 1.6mm) Scintillator (50mm) Earth (Backscattering) Energy spectra of shower particles

  10. AGASA Energy Resolution Angular Resolution

  11. Energy Resolution

  12. The Conversion from S600 to Energy

  13. Time profile of shower particles Over estimation factor Due to the shower front thickness

  14. Delayed particles and Over estimation factor

  15. Major Systematics in AGASAastro-ph/0209422 • Detector • Detector Absolute gain ± 0.7% • Detector Linearity ± 7% • Detector response(box, housing) ± 5% • Energy Estimator S(600) • Interaction model, P/Fe, Height -10% ±15% • Air shower phenomenology • Lateral distribution function ± 7% • S(600) attenuation ± 5% • Shower front structure +5% ± 5% • Delayed particle(neutron) +5% ± 5% • Total±0% ± 18%

  16. Energy Spectrum by AGASA (θ<45) 10 obs. / 1.6 exp. 4.0σ

  17. Red -Inside Array Green –Well Inside 4.6 x 1016 m2 s sr

  18. Energy determined by Ne andEnergy determined by S600 Ne  8.5x1018eV S600  9.3x1018eV

  19. Akeno 1km2 and AGASA

  20. AGASA vs HiRes (astro-ph) See new paper: Energy determination in AGASA (astro-ph/0209422)

  21. 2001 ICRC 2002 Astro-ph AGASA & HiRes 1999 ICRC

  22. Possible Systematics in HiResMost of them are energy dependent Air Fluorescence yield • Total yield is known with 10% accuracy • Yields of individual lines are not known well • Rayleigh Scattering effect (∝1/λ4) Light transmission in air • Mie Scattering • Horizontal attenuation, Scale Height, Wind velocity, Temperature  single model represents whole data • Horizontal 12km (1999)  25km (2001) Cherenkov light subtraction Errors in Mono analysis • Aperture estimation (Narrow F.O.V.) • Chemical composition / Interaction dependent

  23. Arrival Direction Distribution No Large Scale Anisotropy. Event Clusters: 1Triplet and 6 doublets P(chance) ~ 0.07%. Interacting Galaxy VV141 in the direction of triplet at 100Mpc. Arrival directions of 59events > 4 x1019eV observed by AGASA

  24. Arrival Direction Distribution of EHE cosmic rays >4x1019eV >1019eV

  25. The distribution of Space angle between eventsSuggest compact sources!! 5 sigma effect 3 sigma effect >1019eV >4x1019eV

  26. V1-V2 plot in Galactic coordinateOuter Galaxy region|bII|<60, 90<lII<180 1. From 1019eV 2. Extended linearly ΔｂII 20ox20o ΔｌII Log(E)>19.00 19.15 19.70

  27. The polarization angle 40 degrees 1019eV 1.8 degree x 10 degree box

  28. Cosmic Ray propagation in Galactic Magnetic Field ΔｂII ΔｌII Aperture By Stanev

  29. Energy spectrum of Cluster events∝E -1.8+-0.3 Cluster Component

  30. Gamma Rays in EHECR With 95% C.L. γ/all< 28% at >1019eV γ/all < 67% at >1019.5eV

  31. Summary • Super GZK particles exist • AGASA  HiRes inconsistency??? • Statistically consistent, but we need cross-calibration • Origin of EHECR (Possible scenario) • Decay of Heavy Relics in our Halo • Z-burst by EHE neutrino • Violation of Special Relativity • AGN’s, GRB’s or other astronomical objects • Clear evidence for point sources of EHECR • Elongated shaped excess of ~10°in 2-D correlation map • Consistent with the charged particle deflection by G.M.F. The beginning of the EHECR astronomy

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