Ultra High Energy Cosmic Rays-- observational results --
M.Teshima
Max-Planck-Institut für Physik, München
Erice Summer SchoolJuly. 2004
Victor Hess 1912
Discovery of Cosmic Rays
John Linsley at Volcano Ranch (~1960)First discovery of super-GZK events
Cosmic Ray Energy Spectrum
P
γ3K
ΔN
π
GZK mechanism
AGASA Energy Spectrum
Super GZK part.~1/km2 century
Background Radiations
in the universePair creation
GZK
Cosmic Rays and Neutrino
Candidates for EHE C.R. accelerator
Pulsar SNR A.G.N.
GRB
Radio Galaxy Lobe
Synchrotron radiation
GZK limit
Hidden HILLAS PLOT IIAnn. Rev. Astron. Astrophys. 1984, 22; p425-444
Cosmic Ray Propagation in our Galaxy
Deflection angle ~ 1 degree at 1020eVAstronomy by hadronic particles?
Cosmic Ray Propagation inGalactic Disk and Inter Gal.
Exposure in ICRC2003
Air Shower Phenomena
AGASAAkeno Giant Air Shower
Array
111 Electron Det.27 Muon Det.
0 4km
HiRes ExperimentAir Fluorescence detector
HiRes ExperimentAir Fluorescence technique
Measure Shower Development in the atmosphereEssentially Carolimetric measurement
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 DeterminationLocal density at 600mGood energy estimator by M.Hillas
E=2.13x1020eV, E >= 1.6x1020eV
Third Highest event97/03/30 150EeV
40 detecters were hit
The Highest Energy Event (~2.46 x1020eV) on 10 May 2001
Attenuation curve S(600) vs Nch
1018eV Proton
Atmospheric depth
S600 Attenuation curve
0-45°
0-60°
Atmospheric depth
20.0
19.5
19.0
18.5
18.0
The Conversion from S600 to Energy
Muon/Neutrino
Ele. Mag
S600 Intrinsic fluctuation for
proton and iron
Proton
Iron
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 ±15%
Air shower phenomenology Lateral distribution function ± 7% S(600) attenuation ± 5% Shower front structure ± 5% Delayed particle(neutron) ± 5%
Total ± 18%
Energy Resolution
30% 25%
mainly due to measurement errors (particle density measurement and core location determination)not due to shower fluctuation
Energy Spectrum by AGASA (θ<45)
11 obs. / 1.8 exp. 4.2σ
5.1 x 1016 m2 s sr
The Energy spectrum by AGASA Red: well inside the array
(Cut the event near the boundary of array)
Akeno 1km2 and AGASA
HiRes NSF events200-300EeV
HiRes I, II mono spectrum
AGASA vs HiRes (astro-ph)
Recent spectra (AGASA vs. HiRes@Tsukuba ICRC)
~2.5 sigma discrepancy between AGASA & HiRes
Energy scale difference by 25% vs. HiRes-stereo
vs. HiRes-I
vs. HiRes-II
World Energy Spectrum by M.Nagano 2002
Stecker 2003
by Douglas Bergman
20% energy variation
AGASA vs HiRes
AGASA HiRes
GZK-HypothesisExtended spectrumSuper-GZK
~2.4 σ
~4.2σ
~ 0 σ~ 0σ
~2.3 σ
Statistics
40% uncertainty
Impact parameter
Air Fluorescence yieldMeasurement
1. Bunner2. Kakimoto et al3. Nagano et al
Rayleigh Scattering
∝λ‐4
Possible Systematics in HiResMost of them are energy dependent
Air Fluorescence yield Total yield is known with 10~20% 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 subtractionBias by Narrow FOV in elevation angleErrors in Mono analysis
Aperture estimation (Narrow F.O.V.) Chemical composition / Interaction dependent
Arrival Direction Distribution >4x1019eVzenith angle <50deg.
Isotropic in large scale Extra-GalacticBut, Clusters in small scale (Δθ<2.5deg) 1triplet and 6 doublets (2.0 doublets are expected from random) One doublet triplet(>3.9x1019eV) and a new doublet(<2.6deg)
Space Angle Distribution of Arbitrary two events >4x1019eV
Arrival Direction Distribution >1019eV
Space Angle Distribution
Log E>19.6Log E>19.4
Log E>19.2Log E>19.0
Energy spectrum of Cluster events∝E -1.8+-0.3
Cluster Component
Density of sourcesby Kachelriess and Semikos 2004
2D-Correlation Map in (ΔlII ,ΔbII )Log E >19.0eV, 3. 4σ Log E >19.2eV, 3. 0σ
Log E >19.4eV, 2.0σ Log E >19.6eV, 4.4σΔΔllIIII
ΔΔbbIIII
Cosmic Ray propagation in Galactic Magnetic Field
By Stanev
ΔbII
ΔlII
Aperture
Correlation with BL Lacsby Gorbnov et al. 2004
Full sky map of deflection angles
By K.Dolag, D.Grasso, V.Springel, and I.Tkachev
Expected Auto correlationYoshiguchi et al. 2004
Number density of sources~10-5 Mpc-3
Shower maximum Xmax
Fe P
Atmospheric depth
Num
ber
of s
how
er p
arti
cles
ρμ(1000) distributionby AGASA 2002
Akeno 1km2 (A1): Hayashida et al. ’95 Haverah Park (HP): Ave et al. ’03Volcano Ranch (VR): Dova et al. (ICRC ‘03)HiRes (HiRes): Archbold et al. (ICRC ‘03)
A1: PRELIMINARY
1017.5eV – 1019eV (Akeno 1km2 array)
Gradual lightening
Above 1019eV (AGASA)
Fe frac.: <40% (@90% CL)
Chemical composition study by muons(p+Fe composition assumption; AIRES+QGSJET)
PRELIMINARY
Limits on gamma-ray fraction
Gamma-ray fraction upper limits (@90%CL)
34% (>1019eV)(/p<0.45)
56% (>1019.5eV)(/p<1.27)
to observed events Topological defects (Sigl et al. ‘01) (Mx=1016[eV]; flux normalised@1020eV )Z-burst model(Sigl et al. ‘01)(Flux normalised@1020eV)
SHDM-model (Berezinski et al. ‘98) (Mx=1014[eV]; flux normalised@1019eV )
Assuming 2-comp. (p+gamma-ray) primaries
Fly’s Eye highest energy eventHalzen and Hooper 2002
HE and UHE Neutrino flux D.Tress and A.Anchordoqui 2004
SummarySuper GZK particles exist AGASA HiRes statistically consistent Origin of UHECR (Possible scenario)
Decay of Heavy Relics in our Halo (WIMPZILLA) Z-burst by EHE neutrino almost dead Violation of Special Relativity AGNs, BL-Lacs, GRBs
Super GZK particles; no evidence for gamma rays May be difficult for top-down scenarios
Evidence for point sources of UHECR AGASA HiRes statistically consistent Clusters nice chance to solve the origin of UHECRs Auger/EUSO – energy spectrum in each point source