AGASA resultsAnisotropy of EHE CR arrival direction distribution

M. TeshimaICRR, U of Tokyo

Contents

Anisotropy at 1018eVGood evidence for Galactic Cosmic Rays

Anisotropy above 1019eVClusters in the arrival directionsNew Astrophysics

Cosmic Ray Propagation in our Galaxy

Deflection angle < 1 degree at 1020eV

Neutrons can travel galactic scale without decaying above 1018eV

By M.Takeda

Candidates for C.R. acceleratorPulsar SNR A.G.N.

GRB

Radio Galaxy Lobe

Anisotropy at 1018eV

Data A20: (~12km2) for 5years AGASA(~100km2) for 10years

Event selection Core Location: inside the array Nhit >= 6 detectors χcore

2<5.0, χdir2<5.0

Number of Events 284,000 events (>1017eV)

First Harmonic Analysis (Sep.1986-May.2001, 284,416 events)

Galactic Cosmic Rays up to 1018eV ●Use 284,000events over 15yrs operation by AGASA+AGASA Prototype● >4σ near G.C. and -4σ near A.G.C.

Amplitude ~4% StatisticalSignificance

Point Sources

or Cosmic Ray flow

Dipole (G.C.-AGC) distributionLog(E) = 18.0-18.5

G.C Anti G.C.

DC excess with 6 degrees rad. ApertureLog(E) = 18.0-18.5

Auto-correlation at 18.0-18.5

ConclusionHarmonic Analysis, Global excess map (p.s. = 20o) Pch < 10-4 (consistent with previous reports) 4 σ near the GC and -4σ near AGC The anisotropy of cosmic ray arrival direction at 1018eV

observed by AGASA can be fitted with dipole distribution (GC --- AGC)

Point source analysis(p.s. = 6o), Self-correlation analysis

No evidence for point sources. The data favors the diffuse sources.

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 DistributionCompact sources!!

~5 sigma effect

The number of point sourcesAssume the same intensity sources, fit the multiplicity distribution

120 – 430 sources

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

3.5σ at 40 degrees

1.8 degree x 10 degree box

1019eV

Cosmic Ray propagation in Galactic Magnetic Field

By Stanev

ΔｂII

ΔｌII

Aperture

Linearly extended halo in 2-D correlation map can be understood as deflected charged particles by G.M.F.

Magnetic field in diskAxial Symmetric Bi-symmetricParity Even Odd

Magnetic field in Halo Strength Bz~0.3μGParity Odd Even

Restrict G.M.F. structures(by GMT and MT)

Trace back cosmic rays up to Galactic Halo surface of 20kpc

Identify sources!!

On going

>19.0

>19.6>19.5>19.4

>19.3>19.2>19.1

>19.7

Self-correlation 2D-map (20ox20o)

Differential Energy Spectrum of pair events(bin width = 0.2 decade)

X2.95X1.51

X2.04 X2.63

Structure?

dF/dE ~ E-1.8+-0.3

Correlation as func. Of energy ratio between two events

x1.86(+0.32-0.21) x4.46(+0.55-0.48)

X2.4

He ? ?

Possible Scenario

P

BCNOHe

Rigidity dependent?Photo-disintegration cutoff?

First bump --- 1ry and 2ndry p/nSecond bump --- 1ry HeThird bump --- 1ry BCNO

Fe

Naturally, Fe is expected at 2-3x1020eV.

p.d. p.d.

Monte Carlo RealizationBy T.Yamamoto et al

Prelim

inary

Uniform SourceStandard Chem. Comp.10nG Magnetic FieldRequire Clustering

Conclusion (>1019eV)

Clear evidence for point sources of EHECR

Elongated shaped excess of ~10°in 2-D correlation mapConsistent with the charged particle deflection by G.M.F.

Interesting structures in the energy spectrum of cluster events (Three bumps?)

Consistent with P, He, BCNO composition

The beginning of the EHECR astronomy

To the future

Clusters give you important information Sources (Fe primary favors GRB remnants)

the chemical composition study for super GZK particle is important

G.M.F. structure can be uniquely solved Constrain the inter-galactic Magnetic Field

4πcoverage of sky is really important Northern Hemisphere; Easy to understand G.M.F.

structure, because it is simple toward outer galaxy. Southern hemisphere; Observation is essentially

important to understand whole G.M.F. structure.

Systematics and Resolution

In Mono analysis Composition Proton/Fe??? Interaction QGSJET/SIBYLL Scale height of Mie layer

In Atmosphere (In Mie Scattering) Horizontal attenuation Scale height 1-D model reality (locality)

E (Rp) dependence10,000km2sr 100% efficiency upto Rp ~ 40km