agasa update m. teshima icrr, u of tokyo @ cfcp mini workshop oct 4 2002
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AGASA update
M. TeshimaICRR, U of Tokyo
@ CfCP mini workshopOct 4 2002
AGASAAkeno Giant Air Shower
Array
111 Electron Det.27 Muon Det.
0 4km
Exposures in various experiments
AGASA: Ground Array
HiRes: Air Fluorescence
Energy DeterminationLocal density at 600mGood energy estimator by M.Hillas
E=2x1020eV, Emin = 1.6x1020eV
Attenuation curve S(600) vs Nch
1018eV Proton
Atmospheric depth
S600 Intrinsic fluctuation for
proton and iron
Proton
Iron
Energy Determination in AGASA
Please read astro-ph/0209422
Detector Calibration in AGASA experiment
Detector Gain by muons in each run
Cable delay (optic fiber cable)
Gain as a function of time(11years data)
Accuracy of 100ps by measuring the round trip time in each run
Detector Position
Survey from AirplaneΔX, ΔY= 0.1m, ΔZ= 0.3m
Linearity as a function of time(11years data)
Detector Simulation (GEANT)
Detector Housing (Fe 0.4mm)Detector Box (Fe 1.6mm)Scintillator (50mm)Earth (Backscattering)
vertical θ = 60deg
Detector Response
Energy spectra of shower particles
Energy Resolution Angular Resolution
AGASA
Energy Resolution
The Conversion from S600 to Energy
Time profile of shower particles
Over estimation factorDue to the shower frontthickness
Delayed particles and Over estimation factor
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%
Energy Spectrum by AGASA (θ<45)
10 obs. / 1.6 exp. 4.0σ
Red -Inside ArrayGreen –Well Inside
4.6 x 1016 m2 s sr
Energy determined by Ne andEnergy determined by S600
Ne 8.5x1018eV
S600 9.3x1018eV
Akeno 1km2 and AGASA
AGASA vs HiRes (astro-ph)See new paper: Energy determination in AGASA (astro-ph/0209422)See new paper: Energy determination in AGASA (astro-ph/0209422)
AGASA & HiRes
2001 ICRC 1999 ICRC 2002 Astro-ph
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/λ∝ 4)
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 subtractionErrors in Mono analysis
Aperture estimation (Narrow F.O.V.) Chemical composition / Interaction dependent
Arrival Direction Distribution
Arrival directions of 59events > 4 x1019eV observed by AGASA
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 Direction Distribution of EHE cosmic rays
>4x1019eV
>1019eV
The distribution of Space angle between events
Suggest compact sources!!5 sigma effect
>4x1019eV >1019eV
3 sigma effect
V1-V2 plot in Galactic coordinate
Outer Galaxy region|bII|<60, 90<lII<180
Log(E)>19.00 19.15 19.70
1. From 1019eV2. Extended linearlyΔb
II
ΔlII
20ox20o
The polarization angle
40 degrees
1.8 degree x 10 degree box
1019eV
Cosmic Ray propagation in Galactic Magnetic Field
By Stanev
ΔbII
ΔlII
Aperture
Energy spectrum of Cluster events∝E -1.8+-0.3
Cluster Component
Gamma Rays in EHECR
With 95% C.L.γ/all < 28% at >1019eVγ/all < 67% at >1019.5eV
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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