agasa results anisotropy of ehe cr arrival direction distribution
DESCRIPTION
AGASA results Anisotropy of EHE CR arrival direction distribution. M. Teshima ICRR, U of Tokyo. Contents. Anisotropy at 10 18 eV Good evidence for Galactic Cosmic Rays Anisotropy above 10 19 eV Clusters in the arrival directions New Astrophysics. Cosmic Ray Propagation in our Galaxy. - PowerPoint PPT PresentationTRANSCRIPT
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