平成25年度共同利用研究成果発表会

宇宙線望遠鏡による極高エネルギー宇宙線の研究
佐川 宏行 (東京大学宇宙線研究所)
Telescope Array Collaboration2013年12月21日

2013/12/21

1Outline• Telescope Array (TA)• TA detector/papers• Recent preliminary TA results• Energy spectrum• Composition• Anisotropy• Hot spot?

• TA Extensions, on-going R&Ds, proposals• TAx4, TALE
• Associate experiments: radio (TARA, GHz), TA/LMA• Summary
2013/12/21

related toTA burst events2

Telescope Array Collaboration
T. Abu-Zayyada, M. Allena, R. Andersona, R. Azumab, E. Barcikowskia, J. W. Belza, D. R. Bergmana,
S. A. Blakea, R. Cadya, M. J. Chaec, B. G. Cheond, J. Chibae, M. Chikawaf, W. R. Chog, T. Fujiih, M. Fukushimah,i,K. Gotoj, W. Hanlona， Y. Hayashij, N. Hayashidak, K. Hibinok, K. Hondal, D. Ikedah, N. Inouem, T. Ishiil,
R. Ishimorib, H. Iton, D. Ivanova,o, C. C. H. Juia, K. Kadotap, F. Kakimotob, O. Kalashevq, K. Kasaharar, H. Kawais,
S. Kawakamij, S. Kawanam, K. Kawatah, E. Kidoh, H. B. Kimd, J. H. Kima, J. H. Kimd, S. Kitamurab, Y. Kitamurab,V. Kuzminq, Y. J. Kwong, J. Lana, J.P. Lundquista, K. Machidal, K. Martensi, T. Matsudat, T. Matsuyamaj,J. N. Matthewsa, M. Minaminoj, K. Mukail, I. Myersa, K. Nagasawam, S. Nagatakin, T. Nakamurau, H. Nanpeij,T. Nonakah, A. Nozatof, S. Ogioj, S. Ohc, M. Ohnishih, H. Ohokah, K. Okih, T. Okudav, M. Onon, A. Oshimaj,S. Ozawar, I. H. Parkw, M. S. Pshirkovx, D. C. Rodrigueza, G. Rubtsovq, D. Ryuy, H. Sagawah, N. Sakuraij,A. L. Sampsona, L. M. Scotto, P. D. Shaha, F. Shibatal, T. Shibatah, H. Shimodairah, B. K. Shind, T. Shirahamam,J. D. Smitha, P. Sokolskya, R. W. Springera, B. T. Stokesa, S. R. Strattona,o, T. A. Stromana, M. Takamurae,
A. Taketaz, M. Takitah, Y. Tamedak, H. Tanakaj, K. Tanakaaa, M. Tanakat, S. B. Thomasa,
G. B. Thomsona, P. Tinyakovq,x, I. Tkachevq, H. Tokunob, T. Tomidaab, S. Troitskyq, Y. Tsunesadab, K. Tsutsumib,
Y. Uchihoriac, F. Urbanx, G. Vasiloffa, Y. Wadam, T. Wonga, H. Yamaokat, K. Yamazakij, J. Yangc,
K. Yashiroe, Y. Yonedaj, S. Yoshidas, H. Yoshiiad, R. Zollingera, Z. Zundela~120 collaborators in 5 countries
Japan, USA, Korea, Russia, Belgium

aUniversity of Utah, bTokyo Institute of Technology, cEwha Womans University, dHanyang University, eTokyo University of Science,fKinki University, gYonsei University, hInstitute for Cosmic Ray Research, Univ. of Tokyo,iKavli Institute for the Physics and Mathematics of the Universe (WPI), Todai Institutes for Advanced Study, the University of Tokyo,

jOsaka City University, kKanagawa University, lUniv. of Yamanashi, mSaitama University, nAstrophysical Big Bang Laboratory, RIKEN,oRutgers University, pTokyo City University, qInstitute for Nuclear Research of the Russian Academy of Sciences, rWaseda University,sChiba University, tInstitute of Particle and Nuclear Studies, KEK, uKochi University, vRitsumeikan University, wSungkyunkwan University,
xUniversite Libre de Bruxelles, yChungnam National University, zEarthquake Research Institute, University of Tokyo,

aaHiroshima City University, abAdvanced Science Institute, RIKEN, acNational Institute of Radiological Science, adEhime University

2013/12/21

3

14 telescopes
Refurbished HiRes
Middle Drum(MD)TA detector in Utah
3 com. towers

39.3°N, 112.9°W~1400 m a.s.l.

Surface Detector (SD)507 plastic scintillator SDs
1.2 km spacing
700 km2

CLF
LongRidge(LR)

Fluorescence Detector(FD)ELS

3 stations
38 telescopes
12 telescopes

12 telescopes

2013/12/21

Black Rock Mesa (BR)4

平成25年度共同利用研究採択課題
整理
番号

課題名

研究代表者

合計額（千円）F14

宇宙線望遠鏡による極高エネルギー宇宙線の研究

佐川 宏行

900

F15

TA実験サイトでの超高エネルギー宇宙線観測のための新型検出器の開発

野中 敏幸

500

F16

最高エネルギー宇宙線の電波的観測の研究

池田 大輔

800

F17TA実験における中央レーザー装置ステアリングシステムの開発

有働 慈治

250

F18

ラジコンヘリコプターによるTA大気蛍光望遠鏡キャリブレーション

多米田 裕
一郎

350

F19

小型電子加速器による空気シャワーエネルギーの絶対較正の研究

芝田 達伸

600

F20

TA地表検出器の低エネルギー側高感度化（TALE計画）と宇宙線異方性の研究

川田 和正

300

F21

TA-EUSO64chマルチアノードPMTの較正とCRAYSとの比較

竹田 成宏

450

F23

大気分子制動放射マイクロ波の検出と検出器開発

荻尾 彰一

400

合計

2013/12/21

9課題

どうもありがとうございます

4,550
5

Refereed papers in 2013
• The cosmic-ray energy spectrum observed with the surface detector of
the Telescope Array experiment• T. Abu-Zayyad et al., Astrophysical Journal Letters, 768 (2013) L1

SD spectrum• The energy spectrum of ultra-high-energy cosmic rays measured by theTelescope Array FADC fluorescence detectors in monocular mode
• T. Abu-Zayyad et al, Astropart. Phys., 48 (2013) 16

FD mono spectrum• Search for correlations of the arrival directions of ultra-high energy cosmic
rays with extragalactic objects as observed by the Telescope ArrayExperiment• T. Abu-Zayyad et al., Astropart. Phys., 777 (2013) 88

Anisotropy• Upper limit on the flux of photons with energies above 1019 eV using theTelescope Array surface detector• T. Abu-Zayyad et al., Phys. Rev. D 88 (2013) 112005

2013/12/21

Photon flux limit
6ICRC2013 presentations
SubjectID

O PSubjectID

O PSubjectID

O P

Highlight talk128

OTA SD simu. andanalysis

395

PHybrid trigger

134

PTA general118

P

TALE hybrid simu. andanalysis

389

PRadio echo
detection with ELS

360

P

TA/Auger joint papers

TA next 5 years

121

PLSS@HE935

PTARA

1192

Point-likesources@1018

310

P

SD composition

536

P

CR radar echoes in
TARA data639

PTA extensions
R&DLSS aniso@1018

311

P

BR/LR hybridcomposition

965PTALE717

UHE photon and nuwith FD524

PTA spectrum
summary

221

O

Surface muon
detector

298

PSpectrum fit

136

TA compositionsummary132

O

FD PMT monitoring

952

P

Shower frontstructure130

TA anisotropy
summary1033

O

Octocopter lightsource test

1218

UHE photon and nu
with SD

149

Composition: TA
analysis for PAO
model964

O

GHz radio detection
with ELS

MD hybrid spectrum
and composition

794

P

TA/Auger Large-scale
joint anisotropy study

679

O

Shower universality
for NICHE

Correlations ofarrival directions

133P

FD calib. with ELS

507OStereo masscomposition

512

PCLF

142

P

BR/LR hybridspectrum

358

PPortable laser

526

P

BR/LR monospectrum

476

P

Octocopter lightsource test

504

P

Data and Corsika
simulation

353

NICHE365

2013/12/21

O
PO

OO

O

OO
P

983

P

40 papers (14 oral)
including
4 TA/Auger joint papers ( 3 oral). Auger light source with TA FD. TA Xmax recon. for Auger ad hoc model. TA/Auger joint anisotropy study
7

Energy spectrum

2013/12/21

8

TA SD energy spectrum(5-year data)

ICRC2013
preliminary

SD energy isscaled to FD energy
19

𝐸𝐸2 = 5.68 ± 1.05 × 10
𝛾𝛾2 = −2.685 ± 0.030

𝑒𝑒𝑒𝑒

Significance of suppression(APP,2003)(PLB,2010)(PRL,2008)(PRL,2008)(ICRC2013)2013/12/21

Suppression consistent
with GZK cutoff

For E > 1019.8 eV,N(cont. spectrum) = 68.1
N(observed)= 26
Continuous spectrum is
excluded at 5.74𝜎𝜎

TA and Auger fluxes were different
by ~25% in energy scale9TA spectrum vs Auger spectrum
Rapporteur talk by Y.Tsunesadaat ICRC2013

Energy scale uncertainty. TA:21%. Auger: 14%

TA (■) and Auger (Ex1.1) (○)
similar below 1019.4 eV
19.4 eV
2013/12/21 different above 1010

Electron Light Source (ELS)Electron beam

T.ShibataICRC2013
preliminary

BR FDstation

100m
Cosmic ray
Electron beam

• 40-MeV, 109 electrons (typical)• End-to-end FD energy calibration• Real data
• ELS

• Energy/beam current frommonitor• FADC counts from FD

An image of data
Measured with FD• MC data• Shower generation•Geant4.9.5 or 4.9.6 (∆E → AFY)

• FD simulation•TA official software.

Air Fluorescence Yield (AFY) by using Reference Model proposed by B. Keilhauer et al.
(UHECR2012, arXiv:1210.1319)

2013/12/21

T and humidity dep.

11

Air Fluorescence Yield at 337 nm
by ELSICRC2013
preliminary• AirFLY = 5.61 ± 0.06 (stat) ± 0.22 (sys)at 1013 hPa and 293 K• Measurement in situ at TA•

ELS(data)= 0.96±0.01 𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠
AirFLY(MC)at ~860 hPa and -17 ~ 17oC

2013/12/21± 0.15 𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠

12

Mass Composition

2013/12/2113

FD stereo Xmax

Y.Tameda
ICRC2013, 512
preliminary• FD stereo 5-year data (Nov., 2007 – Nov. 2011)• Data: TA• Red histogram: QGSJET-II-03 proton model• Blue histogram: QGSJET-II-03 iron model

2013/12/21

Both Data & MCwith bias of. Reconstruction. Cut

The TA data is consistent with QGSJET-II-03 proton prediction.

14

ICRC2013 preliminary

FD stereo Xmax

TA data: consistent with QGSJET-II-03 proton prediction ( E > 1018.2 eV)
Need more data for E > 1019.4 eV
Similar result is obtained for MD hybrid (FD+SD) Xmax
2013/12/21

15

Anisotropy
TA 5-year SD data

2013/12/21

16

Autocorrelations

P.Tinyakov
ICRC2013 preliminary

No small-scaleanisotropyP(δ):
The probability thatthe excess of pairs (<δ)
occurs in a uniform
distribution
Small P(δ):
departure fromisotropy

2013/12/21

0.004

Separation angle 𝛿𝛿17

ICRC2013 preliminaryOral, 1033

Correlations with AGN• 472 AGN from 2006 Veron catalog with z < 0.018• E > 57 EeV, zenith angle < 45o, N = 42 (5 yr)• Separation angle = 3.1o

TA events:
correlated● not correlated●AGN• Probability to hit AGN with a single event po = 0.24
• 17 events correlate out of 42 (0.40) ⟹ p = 1.4%

2013/12/2118

ICRC2013 preliminary

Correlations with LSS(Large-Scale Structure)• Proton LSS model:• 2MASS Galaxy Redshiftcatalog (XSCz)• gray pattern

5%• E > 57 EeV, 6o smearing• White dots: 52 TA data
• E > 57 EeV• zenith angle < 55o360o

Theta: Gaussian deflection angle

0oGalactic plane
2013/12/21

p-value of Structure (LSS) model ~10%
p-value of Isotropy model ~ 0.1%
for 6o smearing(smaller p-value lesser compatibility)
19

Hot spot

COSPA2013Preliminary• Loose cut: 52 events -- > 72 events (E > 57 EeV)
• No 1.2-km border cut, …
• Angular resolution does not change very much

• Oversampling with circles of 20-degree radiusEquatorialcoordinates• Significance 5.1σ (before correction)• Chance probability： being estimated (~ 3.6σ)
2013/12/21

20

Energy spectrum by TA SD with fit

Preliminary

p + γCMB  p + Δresonancep + γCMB  p + e+ + ep-LSS model
p-isotropy model

Propagation: CRPropa v2.0, SOPHIA: pion prod.
2013/12/21

E.KidoPreliminary

Fit with extragalactic protons. LSS (~2MASS XSCz). isotropyFit curve. The spectrum at the source isa power law of index γ. The source density is a constanttimes a factor (1+z)m
m: the evolution parameterz : redshift. and E and normalizaton
Fit result (γ, m, E) for LSS
γ = -2.37+-0.08
m = 5.2+1.2-1.3
logE’/E = -0.02+0.04 – 0.05
m = 5 (AGN)m = 4.8 (GRB)m = 3 (QSO)

21

TA extension plans
andon-going R&D• TAx4: quadruple aperture extension for highest
energy cosmic rays
• TALE: TA low energy extension down to 1016.5eV• Associate experiments

2013/12/21

22

TA×4 proposal・ If the suppression is proton GZK cutoff,
we would observe anisotropy.
・ Now there are hints at 3σ level for TA

TALE FD

TAx4 SD• Plan to expand TA by 4 times (~3000 km2) TA MD FD• 500 scintillator counters with 2.1 km spacing(Japanese side)•Proposal submitted for a grant this Oct.

• 10 refurbished HiRes telescopes(US side)

TALE SD• JFY2014 – 2015: 2-year construction• JFY2016 – 2018: 3-year observation• By Mar, 2019
TA LR FD• 20 years of TA SD data
• 14 years of TA hybrid data (Escale, Xmax)• Study of anisotropy• Anistoropy at 3𝜎𝜎 level (5-year TA SD data)↓• Expect 5𝜎𝜎 level anisotropy (20-year TA SDdata)• More statistics for• the spectrum above suppression• Xmax around suppression

2013/12/21• UHE
gamma and neutrino search

TA SD
TA BR FD

TAx4 FD23

TALE (TA Low-energy Extension)

ICRC2013
Oral, 717

down to 1016.5 eV• E = 1016.5 – 1019 eV• Second knee at ~1017.5 eV?
• Drastic change of composition
at 1017~1018 eV?

• ~1017 eV cosmic ray shower:
compatible with LHC center-ofmass energy↓• Transition from galactic toextra-galactic cosmic rays?

TALE layout
TA FD/TALE FD?

101 TALE SDs

2013/12/21

24

TALE (TA Low-energy Extension) 10 TALE FDs:
 refurbished HiRes-II telescopes
 installed and running.

 TALE SDs
 35 TALE SDs were deployed among 101 SDs.

 16 SDs in operation

Observed hybrid events

FD data
TALE FD events (data)
2013/12/21

SD data25

TA + TAx4 + TALE + NICHE
FD fullSD partially
In operation(proposal)(proposal)

Log10(E2xF[eV2m-2s-1sr-1])

TALE(16.52619)
GZK cutoff?

25242313

2nd knee?

ankle

1415

1617

1819TAx420

NICHE Log (E/eV) TA
10(15.8 – 18) (18 – 20.8)

21

Precise energy and composition measurementswith between TA and TAx4, and TA and TALE, and TALE and NICHE*,
over 5-decade energy region (1015.8 ~ >1020.8 eV),with absolute end-to-end energy calibration of FD with ELS at TA
NICHE: Non-Imaging CHErenkov detector
2012/11/19

TA EAB meeting26

TA muon detector project

ICRC2013
Poster, 118, 298• One set of 24-m2 scintillator
detector with concrete absorber on
the top• 8x(3-m2 scintillator detectors)• Lead layer sandwiched between twoscintillators• First 9 m2: 12x(0.75 m2)• 1 segment was deployed inside CLF

will be installed outside CLF early nextyear• Auger water → TA site
2013/12/2127

TARA (TA Radar)

ICRC2013
Oral, 1192

• An R&D project to observe radar reflections form cosmic
ray air showers• TARA1.5• April 2011 to July 2012
• 54.1 MHz @ 1.5 kW• TARA40• Summer 2013~• 54.1 MHz @ 40 kW

2013/12/2128

Test of detection of Molecular Bremsstrahlung
Radiation from cosmic-ray air shower• The system of the detection of 12-GHz radio wave toobserve cosmic-ray air-showers was developed• Test: none of the below observed signal• 12-antenna array @ Konan Univ. (T.Yamamoto)• Coincidence with air-shower array @ Osaka City Univ. (S.Ogio)• Pseudo shower using electrons from ELS @ TA (T.Yamamoto et. al.)Test at TA site

2013/12/2129

TA burst events

2013/12/2130

TA burst events (in 5-year SD data)• 10 bursts of shower triggers

Date• Burst: N shower trigger ≥ 3 in 1 ms

• Some events in 5 bursts arereconstructed (right table)• Event: an SD data set recorded bya shower trigger

time

T.OkudaCOSPA2013preliminary

Core position

YYMMDD hhmmss

event

TAburst• Trigger information• Wave forms from SDs

Burst > events > SDs > waveforms(shower trigger)(FADC values)• NLDN: National Lightning
Detection Network• VLF detection• Information• Time, 2D coordinates, peak current• flag:• Cloud-Cloud (C)• Cloud-Ground(G)2013/12/21(H: height above sea level)31

Lateral arriving
Time
Shower front is curved
more for burst events→ Development seems
to start lower sky

Timing from front plane (usec)

Examples of timing and waveforms

T.OkudaCOSPA2013preliminary

4 usec4 usec

2000m

2000m

Distance from the axis (m)Slower risingedge for burstevents

2013/12/21

VEM/binWaveforms
3 VEM

10 usec

3 VEM

Timing (usec)

10 usec32

TA burst events associated with lightning• 10 bursts of shower triggers• Burst: N shower trigger ≥ 3 in 1 ms

• Some events in 5 bursts arereconstructed•

Datetime

T.OkudaCOSPA2013
Core position preliminary

YYMMDD hhmmssevent

TAEvent: an SD data set recorded by a burst
shower trigger
NLDNlightning• Trigger information• Wave forms from SDs

Burst > events > SDs > waveforms(shower trigger)(FADC values)• NLDN: National Lightning
Detection Network• VLF detection• Information• Time, 2D coordinates, peak current• flag: intracloud (C)/Cloud-Ground(G)As the result,Light blue line: <±1ms from the burst: all intracloud (C)Red line:±1ms ~ ± 200ms from the burst: all cloud-ground (G)2013/12/21

33

An example of TA reconstructed
events with lightning
300 m radius:
50% empass

Burst 120706 014911

T.OkudaCOSPA2013preliminary

Height aboveground (m)at 3000 m
North

184307us

Cloud-Cloud

Y (m)184122us

South

300 m
Reconstructedaxis of TA event
Core position(on the ground)of TA events

184219us

X (m)

West

1 km

East

(X, Y): distances are from CLF
2013/12/21

34

Associate experiment: TA/LMA• LMA: Lightning Mapping Array• Array of VHF receiver stations
developed by New Mexico Institute ofMining and Technology (NMT)• 3-D reconstruction, better resolution• TA/LMA: Test LMA in the TA site (Sep~)• 10 receiver stations•(blue points in the figure)

MD FDLR FDBRM FD

LMA detector unit at Long Ridge(with R. Thomas, NMT)
2013/12/21

35

Summary• Recent results for 5-year data
• Energy spectrum• Significance of the suppression consistent with GZK cutoff• 5.7𝜎𝜎 above 1019.8eV• Composition• Consistent with proton• Anisotropy• Hints of anisotropy: significance of ~3σ• Hot spot (20o) ~3.6𝜎𝜎• TA extension plans• TAx4: proposal to quadruple TA aperture• Towards ~5σ anisotropy in 5 years• TALE: low energy extension down to 1016.5 eV• Currently operating 10 full FDs and a part of SD array• TA SD burst events associated with lightning wereobserved• Associated experiments: performed, ongoing, will come2013/12/2136