1 Observation of TeV Gamma Rays with the Tibet Air Shower Array and Future Prospects ICRR,...
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Transcript of 1 Observation of TeV Gamma Rays with the Tibet Air Shower Array and Future Prospects ICRR,...
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Observation of TeV Gamma Rayswith the Tibet Air Shower Array
and Future Prospects
ICRR, University of Tokyo
Kazumasa Kawata
For the Tibet AS Collaboration
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M.Amenomori(1), X.J.Bi(2), D.Chen(3), S.W.Cui(4), Danzengluobu(5), L.K.Ding(2), X.H.Ding(5), C.Fan(6), C.F.Feng(6), Zhaoyang Feng(2), Z.Y.Feng(7), X.Y.Gao(8), Q.X.Geng(8), H.W.Guo(5), H.H.He(2), M.He(6), K.Hibino(9), N.Hotta(10), Haibing Hu(5), H.B.Hu(2), J.Huang(2,3), Q.Huang(7), H.Y.Jia(7), F.Kajino(11), K.Kasahara(12), Y.Katayose(13), C.Kato(14), K.Kawata(3), Labaciren(5), G.M.Le(15), A.F.Li(6), J.Y.Li(6), Y.-Q.Lou(16), H.Lu(2), S.L.Lu(2), X.R.Meng(5), K.Mizutani(12,17), J.Mu(8), K.Munakata(14), A.Nagai(18), H.Nanjo(1), M.Nishizawa(19), M.Ohnishi(3), I.Ohta(20), T.Ouchi(9), S.Ozawa(12), J.R.Ren(2), T.Saito(21), T.Y.Saito(22), M.Sakata(11), T.K.Sako(3), M.Shibata(13), A.Shiomi(23), T.Shirai(9), H.Sugimoto(24), M.Takita(3), Y.H.Tan(2), N.Tateyama(9), S.Torii(12), H.Tsuchiya(25), S.Udo(12), B.Wang(2), H.Wang(2), X.Wang(3), Y.Wang(2), Y.G.Wang(6), H.R.Wu(2), L.Xue(6), Y.Yamamoto(11), C.T.Yan(3),
X.C.Yang(8), S.Yasue(26), Z.H.Ye(15), G.C.Yu(7), A.F.Yuan(5), T.Yuda(9), H.M.Zhang(2), J.L.Zhang(2), N.J.Zhang(6), X.Y.Zhang(6), Y.Zhang(2), YiZhang(2), Zhaxisangzhu(5) and X.X.Zhou(7)
The Tibet AS Collaboration
(1) Dep. of Phys., Hirosaki Univ., Hirosaki, Japan (2) Key Lab. of Particle Astrophys., IHEP, CAS, Beijing, China (3) ICRR., Univ. of Tokyo, Kashiwa, Japan (4) Dep. of Phys., Hebei Normal Univ., Shijiazhuang, China (5) Dep. of Math. and Phys., Tibet Univ., Lhasa, China (6) Dep. of Phys., Shandong Univ., Jinan, China (7) Inst. of Modern Phys., South West Jiaotong Univ., Chengdu, China (8) Dep. of Phys., Yunnan Univ., Kunming, China (9) Fac. of Eng., Kanagawa Univ, Yokohama, Japan(10) Fac. f of Educ., Utsunomiya Univ., Utsunomiya, Japan(11) Dep of Phys., Konan Univ., Kobe, Japan(12) Advanced Research Inst. for Sci. and Engin., Waseda Univ., Tokyo, Japan(13) Fac. of Eng., Yokohama National Univ., Yokohama , Japan
(14) Dep. of Phys., Shinshu Univ., Matsumoto, Japan(15) Center of Space Sci. and Application Research, CAS, Beijing, China(16) Phys. Dep. and Tsinghua Center for Astrophys., Tsinghua Univ., Beijing, China (17) Dep. of Phys., Saitama Univ., Saitama, Japan(18) Advanced Media Network Center, Utsunomiya University, Utsunomiya, Japan(19) National Inst. of Info., Tokyo, Japan(20) Sakushin Gakuin University, Utsunomiya, Japan(21) Tokyo Metropolitan College of Industrial Tech., Tokyo, Japan(22) Max-Planck-Institut fuer Physik, Muenchen, Germany (23) College of Industrial Technology, Nihon University, Narashino, Japan(24) Shonan Inst. of Tech., Fujisawa, Japan(25) RIKEN, Wako 351-0198, Japan(26) School of General Educ.,Shinshu Univ., Matsumoto, Japan
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Tibet-III Air Shower (AS) Array
Number of Scinti. Det. 0.5 m2 x 789 Effective Area for AS ~37,000 m2
Energy region ~TeV - 100 PeV Angular Resolution ~0.4 @10 TeV (Gamma rays) ~0.2 @100 TeV Energy Resolution ~70% @10 TeV (Gamma rays) ~40% @100TeV F.O.V. ~2 sr
4,300 m a.s.l. (606 g/cm2)
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Constant fitting-0.0034o 0.011o+
Systematic pointing error < 0.01o
Absolute EnergyScale error –4.4% +- 7.9%stat +- 8%sys
Energy dependence ofDisplacementsCaused by Geomagnetic field
Verification Absolute energy scale Angular resolution Pointing error
Cosmic Ray Energy Calib. by the Moon’ Shadow
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Energy Spectrum of the Crab Nebula
90%CL
Centered atCrab position
ICRC2007, MexicoSubmitted to ApJ
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0 360R.A. (deg)
Amenomori et al, Science, 314, 439 (2006)
Cygnus region
Tail-In Loss-Cone
MGRO J2019+37 (800 mCrabs @ 20TeV)
MGRO J2031+41 (900 mCrabs @ 20TeV)Cygnus region
Cosmic-ray/Gamma-ray anisotropy
Anisotropy map
0.9 deg. radius
A.A.Abdo et al., ApJ, 664 L91 (2007)
Window size: 5 deg. radius
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Future Plan
Tibet muon detector (MD) project
& Prototype MD in Tibet
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MAGICVERITAS
HESS
Present Status of the TeV Ray Astronomy
90%CL
Antoni et al, ApJ, 608, 865 (2004)Atkins et al, ApJ, 608, 680 (2004)Amenomori et al, ApJ, 633, 1005 (2005)
McKay et al, ApJ, 417, 742 (1993)
Improve sensitivity to gamma raysin 100 TeV region (10 – 1000 TeV)
Number of muons in air showers( <100m from shower core, 4300m a.s.l. )
100TeV proton~50
100TeV gamma~1
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Tibet Muon Detector (MD) Array
7.2m x 7.2m x 1.5m depth Water cell20”PMT x 2 (HAMAMATSU R3600)Underground 2.5m ( ~515g/cm2~19X0)
Material: Concrete pool White paint 192 detctors Total ~10,000 m2
We will count the number of muons by an air shower triggerFull Monte Carlo Simulation
extends AS to~83,000m2
MD ~10,000m2
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Muon Number vs. Shower Size (Simulation) : Sum of particle density by all scintillation det. >> Shower SizeNPE:Sum of photoelectrons by all muon det. >> Muon number (Threshold of MD NPE >10 p.e.)
( Shower Size)
NP
E(
Muo
n N
um
ber)
10TeV 100TeV 1000TeV
20%50%80%
(gamma)
0
(~10TeV)
0
(~100TeV)
Gamma
Gamma
CR
CR
99.8%Rejection
~99.99%Rejection
CR
Gamma
0
NPE( Muon Number)
NPE( Muon Number)
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Future Sensitivity ( 5 or 10 events)
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52m2x 2
Prototype Muon Detector in Tibet
Construction starts from Sep. 2007Data taking starts from Dec. 2007
• Construction feasibility in Tibet• Development of MC simulation• observation above several 100 TeV
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September, 2007 – Start construction
Cement Concrete mixer
On Sep. 1st, start construction Sep. 4th - finish almost digging
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Sep. 13th - finish substructure Oct. 5th – Steel bars, forms
Oct. 15th – concrete works Oct 20th – remove forms
September ~ October
1516 November, 2007 Prototype Muon Detector
16Prototype Muon Detector after covering
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White paint
Pouring very clear well-water Filled up water 1.5 m in depth
Inside of the MD
Clear underground water from a nearby well
20”PMT x 3:(Normal gain x 2, 1/100 gain x 1 for test)
Water depth : 1.5 m
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Summary Tibet MD Project ~83,000 m2 Air Shower array + ~10,000 m2 Water Cerenkov Muon Detector array (~7M US$) Gamma-ray astrophysics in the 100 TeV region (10 – 1000 TeV) – Diffuse and point-like sources – Study on the maximum energy of gamma rays – Origin and acceleration limit of cosmic rays (p0 decay /IC)
Sensitivity (based on detailed simulation) – BG rejection power 99.8% rejected (50% gamma-ray events retained) @ 10 TeV 99.99% rejected (83% gamma-ray events retained) @ 100 TeV – Improve by an order of magnitude compared with the present Tibet AS array >~10 TeV Surpass existing IACTs >~40 TeV Surpass future plans of IACTs
Prototype MD (52 m2 x 2 cells) – successfully completed – data taking started in Dec. 2007 – in good agreement with MC simulation