R01共同利用発表会-Tibet_shio

チベット高原での

高エネルギー宇宙線の研究

塩⾒ 昌司

(⽇本⼤学⽣産⼯学部)

For the Tibet ASg Collaboration

1

令和元年度チベット実験関係

共同利用研究採択課題一覧

１. チベット高原での高エネルギー宇宙線の研究（継続）

(瀧田正人 東京大学宇宙線研究所)

２. Knee領域一次宇宙線組成の研究（継続）

(片寄祐作 横浜国立大学大学院工学研究院)

３. 宇宙線による太陽の影を用いた太陽周辺磁場の時間変動の研究

（継続）

(西澤正己 国立情報学研究所情報社会相関研究系)

４. チベット空気シャワーアレイによる10TeV宇宙線強度の

恒星時日周変動の観測（継続）

(宗像一起 信州大学理学部)

2

チベットグループ共同利用研究経費

執行状況

研究費：

申請額 577万円 à 配分額

150万円

Tibet-ASの維持・運転及び

YAC空気シャワーコア観測装置と

水チェレンコフ型地下ミューオン観測装置の

維持・運転に必要な経費の一部に使用。

旅費：

申請額 985万円 à 配分額

275万円

中国出張海外旅費や宇宙線研での研究打ち合わせに使用。

ご支援、どうもありがとうございます！

3

成果発表

•

査読論文

•

Amenomori et al., PRL, 123/5, 051101(2019)

à

東京大学・横浜国立大学・日本大学・神奈川大学より

合同プレスリリース

•

学会発表

•

ICRC2019(Wisconsin)

15件

•

CRA2019(Itary)

１件

•

TAUP2019(Toyama)

１件

•

AOGS2019(Singapore) １件

•

ISEE太陽圏研究集会2019年2月

１件（予定）

•

日本物理学会2019年秋(山形大学)

４件

•

日本物理学会2020年春(名古屋大学)

３件（予定）

4

5

First Detection of Photons with Energy beyond 100 TeV from an Astrophysical Source

M. Amenomori,

1

Y. W. Bao,

2

X. J. Bi,

3

D. Chen,

4

T. L. Chen,

5

W. Y. Chen,

3

Xu Chen,

3,6

,†

Y. Chen,

2

Cirennima,

5

S. W. Cui,

7

Danzengluobu,

5

L. K. Ding,

3

J. H. Fang,

3,6

K. Fang,

3

C. F. Feng,

8

Zhaoyang Feng,

3

Z. Y. Feng,

9

Qi Gao,

5

Q. B. Gou,

3

Y. Q. Guo,

3

H. H. He,

3

Z. T. He,

7

K. Hibino,

10

N. Hotta,

11

Haibing Hu,

5

H. B. Hu,

3

J. Huang,

3

,§

H. Y. Jia,

9

L. Jiang,

3

H. B. Jin,

4

F. Kajino,

12

K. Kasahara,

13

Y. Katayose,

14

C. Kato,

15

S. Kato,

16

K. Kawata,

,16

,*

M. Kozai,

17

Labaciren,

5

G. M. Le,

18

A. F. Li,

19,8,3

H. J. Li,

5

W. J. Li,

3,9

Y. H. Lin,

3,6

B. Liu,

2

C. Liu,

3

J. S. Liu,

3

M. Y. Liu,

5

Y.-Q. Lou,

20

H. Lu,

3

X. R. Meng,

5

H. Mitsui,

14

K. Munakata,

15

Y. Nakamura,

3

H. Nanjo,

1

M. Nishizawa,

21

M. Ohnishi,

16

I. Ohta,

22

S. Ozawa,

13

X. L. Qian,

23

X. B. Qu,

24

T. Saito,

25

M. Sakata,

12

T. K. Sako,

16

Y. Sengoku,

14

J. Shao,

3,8

M. Shibata,

14

A. Shiomi,

26

H. Sugimoto,

27

M. Takita,

16

,

‡

Y. H. Tan,

3

N. Tateyama,

10

S. Torii,

13

H. Tsuchiya,

28

S. Udo,

10

H. Wang,

3

H. R. Wu,

3

L. Xue,

8

K. Yagisawa,

14

Y. Yamamoto,

12

Z. Yang,

3

A. F. Yuan,

5

L. M. Zhai,

4

H. M. Zhang,

3

J. L. Zhang,

3

X. Zhang,

2

X. Y. Zhang,

8

Y. Zhang,

3

Yi Zhang,

3

Ying Zhang,

3

Zhaxisangzhu,

5

and X. X. Zhou

9

(Tibet ASγ Collaboration)

1

_{Department of Physics, Hirosaki University, Hirosaki 036-8561, Japan}

2

_{School of Astronomy and Space Science, Nanjing University, Nanjing 210093, China}

3

_{Key Laboratory of Particle Astrophysics, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China}

4

_{National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012, China}

5

_{Physics Department of Science School, Tibet University, Lhasa 850000, China}

6

_{University of Chinese Academy of Sciences, Beijing 100049, China}

7

_{Department of Physics, Hebei Normal University, Shijiazhuang 050016, China}

8

_{Department of Physics, Shandong University, Jinan 250100, China}

9

_{Institute of Modern Physics, SouthWest Jiaotong University, Chengdu 610031, China}

10

_{Faculty of Engineering, Kanagawa University, Yokohama 221-8686, Japan}

11

_{Faculty of Education, Utsunomiya University, Utsunomiya 321-8505, Japan}

12

_{Department of Physics, Konan University, Kobe 658-8501, Japan}

13

_{Research Institute for Science and Engineering, Waseda University, Tokyo 169-8555, Japan}

14

_{Faculty of Engineering, Yokohama National University, Yokohama 240-8501, Japan}

15

_{Department of Physics, Shinshu University, Matsumoto 390-8621, Japan}

16

_{Institute for Cosmic Ray Research, University of Tokyo, Kashiwa 277-8582, Japan}

17

_{Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency (ISAS/JAXA), Sagamihara 252-5210, Japan}

18

_{National Center for Space Weather, China Meteorological Administration, Beijing 100081, China}

19

_{School of Information Science and Engineering, Shandong Agriculture University, Taian 271018, China}

20

_{Physics Department, Astronomy Department and Tsinghua Center for Astrophysics,}

Tsinghua-National Astronomical Observatories of China joint Research Center for Astrophysics, Tsinghua University,

Beijing 100084, China

21

_{National Institute of Informatics, Tokyo 101-8430, Japan}

22

_{Sakushin Gakuin University, Utsunomiya 321-3295, Japan}

23

_{Department of Mechanical and Electrical Engineering, Shandong Management University, Jinan 250357, China}

24

_{College of Science, China University of Petroleum, Qingdao, 266555, China}

25

_{Tokyo Metropolitan College of Industrial Technology, Tokyo 116-8523, Japan}

26

_{College of Industrial Technology, Nihon University, Narashino 275-8576, Japan}

27

_{Shonan Institute of Technology, Fujisawa 251-8511, Japan}

28

_{Japan Atomic Energy Agency, Tokai-mura 319-1195, Japan}

(Received 4 April 2019; revised manuscript received 21 May 2019; published 29 July 2019)

We report on the highest energy photons from the Crab Nebula observed by the Tibet air shower array

with the underground water-Cherenkov-type muon detector array. Based on the criterion of a muon number

measured in an air shower, we successfully suppress 99.92% of the cosmic-ray background events with

energies E > 100 TeV. As a result, we observed 24 photonlike events with E > 100 TeV against 5.5

background events, which corresponds to a 5.6σ statistical significance. This is the first detection of

photons with E > 100 TeV from an astrophysical source.

DOI:

10.1103/PhysRevLett.123.051101

PHYSICAL REVIEW LETTERS 123, 051101 (2019)

Editors' Suggestion

Featured in Physics

0031-9007=19=123(5)=051101(6)

051101-1

© 2019 American Physical Society

•

１. チベット高原での高エネルギー宇宙線の研究

全体：

ICRC2019（１）, CRA2019

超高エネルギーγ線：

ICRC2019（６）, TAUP2019, 日本物理学会（４）,日本天文学会（1）

•

２. Knee領域一次宇宙線組成の研究

ICRC2019（３）, 日本物理学会（１）

•

３. 宇宙線による太陽の影を用いた太陽周辺磁場の時間変動の研究

ICRC2019（１）, 日本物理学会（１）

•

４. チベット空気シャワーアレイによる10TeV宇宙線強度の恒星時

日周変動の観測

→（宗像）

ICRC2019（３） , AOGS2019, 日本物理学会（１）

成果発表

チベット

ASg実験 共同研究者

M. Amenomori

1

_{, Y.W. Bao}

2

_{, X.J. Bi}

3

_{, D. Chen}

4

_{, T.L. Chen}

5

_{, W. Y. Chen}

3

_{, Xu Chen}

3,6

_{, Y. Chen}

2

_{, Cirennima}

5

_,

S. W. Cui

7

_{, Danzengluobu}

5

_{, L.K. Ding}

3

_{, J.H. Fang}

3,6

_{, K. Fang}

3

_{, C.F. Feng}

8

_{, Zhaoyang Feng}

3

_{, Z.Y. Feng}

9

_{, Qi Gao}

5

_,

Q.B. Gou

3

_{, Y.Q. Guo}

3

_{, H.H. He}

3

_{, Z.T. He}

7

_{, K. Hibino}

10

_{, N. Hotta}

11

_{, Haibing Hu}

5

_{, H.B. Hu}

3

_{, J. Huang}

3

_{, H.Y. Jia}

9

_,

L. Jiang

3

_{, H.B. Jin}

4

_{, F. Kajino}

12

_{, K. Kasahara}

13

_{, Y. Katayose}

14

_{, C. Kato}

15

_{, S. Kato}

16

_{, K. Kawata}

16

_{, M. Kozai}

17

_,

Labaciren

5

_{, G.M. Le}

18

_{, A.F. Li}

19,8,3

_{, H.J. Li}

5

_{, W.J. Li}

3,9

_{, Y.H. Lin}

3,6

_{, B. Liu}

2

_{, C. Liu}

3

_{, J.S. Liu}

3

_{, M.Y. Liu}

5

_,

Y.-Q. Lou

20

_{, H. Lu}

3

_{, X.R. Meng}

5

_{, H.Mitsui}

14

_{, K.Munakata}

15

_{, Y. Nakamura}

3

_{, H. Nanjo}

1

_{, M. Nishizawa}

21

_,

M. Ohnishi

16

_{, I. Ohta}

22

_{, S. Ozawa}

13

_{, X.L. Qian}

23

_{, X.B. Qu}

24

_{, T.Saito}

25

_{, M. Sakata}

12

_{, T.K. Sako}

16

_{, Y. Sengoku}

14

_,

J. Shao

3,8

_{, M. Shibata}

14

_{, A. Shiomi}

26

_{, H. Sugimoto}

27

_{, M. Takita}

16

_{, Y. H. Tan}

3

_{, N. Tateyama}

10

_{, S. Torii1}

3

_,

H. Tsuchiya

28

_{, S. Udo}

10

_{, H. Wang}

3

_{, H. R. Wu}

3

_{, L. Xue}

8

_{, K. Yagisawa}

14

_{, Y. Yamamoto}

12

_{, Z. Yang}

3

_{, A. F. Yuan}

5

_,

L. M. Zhai

4

_{, H.M. Zhang}

3

_{, J.L. Zhang}

3

_{, X. Zhang}

2

_{, X.Y. Zhang}

8

_{, Y. Zhang}

3

_{, Yi Zhang}

3

_{, Ying Zhang}

3

_,

Zhaxisangzhu

5

_{, and X. X. Zhou}

9

1. 弘前大学理工学部

2. 南京大学

3. 中国科学院高能物理研究所

4. 中国科学院国家天文台

5. チベット大学

6. 中国科学院大学

7. 河北師範大学

8. 山東大学

9. 西南交通大学

10. 神奈川大学工学部

11. 宇都宮大学教育学部

12. 甲南大学理工学部

13. 早稲田大学理工学術院

14. 横浜国立大学大学院工学研究院

15. 信州大学理学部

16. 東京大学宇宙線研究所

17. 宇宙航空研究開発機構宇宙科学研究所

18. 中国気象局

19. 山東農業大学

20. 清華大学

21. 国立情報学研究所

22. 作新学院大学

23. 山東管理学院

24. 中国石油大学

25. 東京都立産業技術高等専門学校

26. 日本大学生産工学部

27. 湘南工科大学

28. 日本原子力研究開発機構

チベット空気シャワー観測装置

8

p

チベット (90.522

o

E, 30.102

o

N) 標高4300 m

現行スペック

p

シンチレーション検出器数

0.5 m

2

x 597

p

空気シャワー有効面積

50,000 m

2

p

観測エネルギー

>TeV

p

角度分解能

0.5 @10TeV

0.2 @100TeV

p

視野

2 sr

à

空気シャワー中の二次粒子(主にe

+/-

,γ)を観測し

一次宇宙線エネルギー、方向を

決定

水チェレンコフ型ミューオン観測装置

à

空気シャワー中のミューオン数を測定し、ガンマ線／核子選別

2014年2⽉ ー 2017年5⽉

有効観測時間：

719⽇

3400m

2

9

ü

地下 2.4m (物質厚 515g/cm2 19X

₀

)

ü

7.35m 7.35m 水深1.5m 水槽

ü

20 ΦPMT (HAMAMATSU R3600)

ü

水槽材質：コンクリート+タイベック

)

log(

1.5

2

2.5

3

3.5

4

)

N

log(

-0.5

0

0.5

1

1.5

2

2.5

3

3.5

4

-3

10

-2

10

-1

10

1

10

2

10

=0

N

(a) Photons MC

)

log(

1.5

2

2.5

3

3.5

4

)

N

log(

-0.5

0

0.5

1

1.5

2

2.5

3

3.5

4

-1

10

1

10

2

10

3

10

=0

N

(b) CRs Data

)

log(

1.5

2

2.5

3

3.5

4

)

N

log(

-0.5

0

0.5

1

1.5

2

2.5

3

3.5

4

-3

10

-2

10

-1

10

1

10

2

10

=0

N

(a) Photons MC

)

log(

1.5

2

2.5

3

3.5

4

)

N

log(

-0.5

0

0.5

1

1.5

2

2.5

3

3.5

4

-1

10

1

10

2

10

3

10

=0

N

(b) CRs Data

ミューオン・カット

10

100TeV

10TeV

総粒⼦数log(Sr)

総粒⼦数log(Sr)

総ミューオン数

lo

g(

S

N

µ)

総ミューオン数

lo

g(

S

N

µ)

総粒⼦数

(Sr)

⽣存率

ミューオンカット後、100TeV領域で

約99.9%の宇宙線を除去、約90%のガンマ線を残す

SNµ=0

SNµ=0

à

カットの最適化

ガンマ線 : MCデータ（Crab軌道、Crab Flux）

宇宙線：実験データ(銀河面・Crab方向除く)

Amenomori et al., PRL (2019)

Amenomori et al., PRL (2019)

「かに星雲」ガンマ線空気シャワー候補事象

fi"ng with NKG func0on

➡

E

_rec

(S50,

q

)

11

Amenomori et al., PRL (2019)

S50 により

Ｅ

決定精度が向上

(10-1000 TeV)

à

~40%@10 TeV , ~20%@100 TeV

円サイズ log(粒子数)

円カラー : 相対到着時間[ns]

à

方向決定

p

総粒子数（Σρ ) = 3256

p

総ミューオン数（S

N

_μ

) = 2.3

p

天頂角 (

q

) = 29.8

o

p

エネルギー = (251 ) TeV

+46

_­43

S50

lateral distribu0on

NKG関数によるフィット

à

エネルギー推定（S50, θ）

2

R.A. (deg.)

Dec. (deg.)

20

21

22

23

24

-2

0

2

4

6

8

10

12

14

16

18

82

84

86

R.A. (deg.)

Dec. (deg.)

20

21

22

23

24

-3

-2

-1

0

1

2

3

4

5

82

84

86

(a) E >10 TeV

(b) E >100 TeV

FIG. S2. Significance maps around the Crab nebula observed by the Tibet AS+MD array for (a) E > 10 TeV and for (b)

E > 100 TeV, respectively. The cross mark indicates the Crab pulsar position.

MUON DISTRIBUTION MEASURED BY THE MD ARRAY

In this paper, the total number of particles detected in the MDs (i.e. ΣN

µ

) is used as the parameter to discriminate

cosmic-ray induced air showers from photon induced air showers. As shown in Fig. 2 in the paper, the muon cut

threshold depends on the Σρ, where Σρ is roughly proportional to energy, and Σρ = 1000 roughly corresponds to

100 TeV.

For E > 100 TeV, the averaged ΣN

µ

for the cosmic-ray background events is more than 100, while the muon cut

value is set to be approximately ΣN

µ

= 10

∼ 30 depending on Σρ. As a result, we successfully suppress 99.92% of

cosmic-ray background events with E > 100 TeV, and observe 24 photon-like events after the muon cut.

Figure S3 shows the relative muon number (R

µ

) distribution above 100 TeV for the Crab nebula events. R

µ

is

defined as the ratio of the observed ΣN

µ

to the ΣN

µ

on the muon cut line in Fig. 2 at the observed Σρ. Three

events among 24 photon-like evens have ΣN

µ

= 0 which corresponds to the leftmost bin corresponds R

µ

= 0 in

Fig. S3. We find a clear bump of muon-less events in R

µ

< 1 region, and the relative muon distribution after the

muon cut (R

µ

< 1) is consistent with that estimated by the photon MC simulation. This is unequivocal evidence for

the muon-less air showers induced by the primary photons from an astrophysical source.

10

-1

10

0

10

1

10

2

10

3

10

4

10

-2

10

-1

10

0

10

1

10

2

10

3

Number o

f events

Relative muon number R

_µ

R

_µ

=0

photon MC

Data BG

Data ON

FIG. S3. Relative muon number (R

µ

) of the Crab nebula events with E > 100 TeV. R

µ

is defined as the ratio of the observed

ΣN

µ

to the ΣN

µ

value on the muon cut line in Fig. 2 at the observed Σρ. The leftmost bin indicates the number of events with

R

µ

= 0. The black points show the number of observed events from the Crab nebula. The solid red histograms and dashed

blue histograms show the photon MC simulation and the observed cosmic-ray background events, respectively. The central

vertical dashed line indicates the muon cut position at R

µ

= 1.

2

R.A. (deg.)

Dec. (deg.)

20

21

22

23

24

-2

0

2

4

6

8

10

12

14

16

18

82

84

86

R.A. (deg.)

Dec. (deg.)

20

21

22

23

24

-3

-2

-1

0

1

2

3

4

5

82

84

86

(a) E >10 TeV

(b) E >100 TeV

FIG. S2. Significance maps around the Crab nebula observed by the Tibet AS+MD array for (a) E > 10 TeV and for (b)

E > 100 TeV, respectively. The cross mark indicates the Crab pulsar position.

MUON DISTRIBUTION MEASURED BY THE MD ARRAY

In this paper, the total number of particles detected in the MDs (i.e. ΣN

µ

) is used as the parameter to discriminate

cosmic-ray induced air showers from photon induced air showers. As shown in Fig. 2 in the paper, the muon cut

threshold depends on the Σρ, where Σρ is roughly proportional to energy, and Σρ = 1000 roughly corresponds to

100 TeV.

For E > 100 TeV, the averaged ΣN

µ

for the cosmic-ray background events is more than 100, while the muon cut

value is set to be approximately ΣN

µ

= 10

∼ 30 depending on Σρ. As a result, we successfully suppress 99.92% of

cosmic-ray background events with E > 100 TeV, and observe 24 photon-like events after the muon cut.

Figure S3 shows the relative muon number (R

µ

) distribution above 100 TeV for the Crab nebula events. R

µ

is

defined as the ratio of the observed ΣN

µ

to the ΣN

µ

on the muon cut line in Fig. 2 at the observed Σρ. Three

events among 24 photon-like evens have ΣN

µ

= 0 which corresponds to the leftmost bin corresponds R

µ

= 0 in

Fig. S3. We find a clear bump of muon-less events in R

µ

< 1 region, and the relative muon distribution after the

muon cut (R

µ

< 1) is consistent with that estimated by the photon MC simulation. This is unequivocal evidence for

the muon-less air showers induced by the primary photons from an astrophysical source.

10

-1

10

0

10

1

10

2

10

3

10

4

10

-2

10

-1

10

0

10

1

10

2

10

3

Number o

f events

Relative muon number R

_µ

R

_µ

=0

photon MC

Data BG

Data ON

FIG. S3. Relative muon number (R

µ

) of the Crab nebula events with E > 100 TeV. R

µ

is defined as the ratio of the observed

ΣN

µ

to the ΣN

µ

value on the muon cut line in Fig. 2 at the observed Σρ. The leftmost bin indicates the number of events with

R

µ

= 0. The black points show the number of observed events from the Crab nebula. The solid red histograms and dashed

blue histograms show the photon MC simulation and the observed cosmic-ray background events, respectively. The central

vertical dashed line indicates the muon cut position at R

µ

= 1.

0

0.5

1

1.5

2

2.5

3

Number of events

0

50

100

150

200

250

300

350

400

MC

Data

>10 TeV

E

(a)

)

2

(deg

2

0

0.5

1

1.5

2

2.5

3

Number of events

0

2

4

6

8

10

12

14

>100 TeV

E

(b)

>10TeV

>100TeV

Data vs MC

First Detection of Sub-PeV

g (5.6s)

12

Amenomori et al., PRL

Supplemental Material (2019)

24 g rays against 5.5 CR BGs

「かに星雲」>10TeVガンマ線放射

Energy (TeV)

1

10

10

2

10

3

)

-1

s

-2

(TeV cm

2

E

×

Differential Flux

-13

10

-12

10

-11

10

-10

10

Tibet AS+MD

Tibet-III

Tibet AS+Proto.MD

HESS(2003-2005)

HESS(2013)

MAGIC

HEGRA

13

曲線：HEGRA のデータ（

Aharonian+, ApJ, 614, 897 (2004)

）を基とし

た場合の逆コンプトンモデルで期待されるガンマ線頻度

Amenomori et al., PRL (2019)

The highest energy g ~450 TeV

Energy (TeV)

1

10

10

2

10

3

)

-1

s

-2

(TeV cm

2

E

×

Differential Flux

-13

10

-12

10

-11

10

-10

10

HAWC (2019)

Tibet AS+MD (2019)

HEGRA (2004)

14

Abeysekara et al. ApJ 881:134 (pp1-13), Received May 28, 2019,

accepted July 3,2019, published August 21, 2019

ＨＡＷＣ（3.3σ>100TeV）との比較

曲線：HEGRA のデータ（

Aharonian+, ApJ, 614, 897 (2004)

）を基とし

SNR G106.3+2.7

15

T. K. Sako ICRC2019 #778

ü

観測領域は CO放射領域から示唆される分子雲の領域と一致

※VERITASの結果と一致

ü

スペクトル解析中

E > 10 TeV

Geminga

16

The energy resolution using S50-metho[3] is estimated to be 40% at 10 TeV and

20% at 100 TeV, and is about 100% for 3TeV estimated directly from the particle

number sum. The angular resolutions (50% containment) are estimated to be

approximately 𝟎.

°

and 𝟎.

°

2 for 10 TeV and 100 TeV photons, respectively.

A water Cherenkov muon detector(MD) array consists of 64 water-Cherenkov-type

detectors installed 2.4 m underground the AS array.

Each muon detector is a waterproof concrete pool filled by water with 7.35 m wide

7.35 m long 1.5 m deep in size, equipped with two 20 inch-in-diameter PMT on

the ceiling, and the inside of each cell is covered with white Tyvek sheets for efficient

reflection of the water Cherenkov light.

Extended Gamma-Ray Emission beyond 10 TeV from Geminga

with the TibetAS+MD array

M. Amenomori

1

_{, Y. -W.Bao}

2

_{, X. J. Bi}

3

_{, D. Chen}

4

_{, T. L. Chen}

5

_{, W. Y. Chen}

3

_{,Xu Chen}

3

_{, Y. Chen}

2

_{, Cirennima}

5

_{, S. W. Cui}

7

_{, Danzengluobu}

5

_{, L. K. Ding3,J. H. Fang3,6, K. Fang}

3

_{, C. F. Feng}

8

_{, Zhaoyang Feng}

3

_{, Z. Y. Feng}

9

_{, Qi Gao}

5

_,

Q. B. Gou

3

_{, Y. Y. Guo}

3

_{, Y. Q. Guo}

3

_{, H. H. He}

3

_{, Z. T. He}

7

_{, K. Hibino}

10

_{,N. Hotta}

11

_{,Haibing Hu}

5

_{,H. B. Hu}

3

_{, J. Huang}

3

_{, H. Y. Jia}

9

_{, L.Jiang}

3

_{,H.-B. Jin}

4

_{, F. Kajino}

12

_{, K. Kasahara}

13

_{, Y. Katayose}

14

_{, C. Kato}

15

_{,S. Kato}

16

_{, K. Kawata}

16

_{, W.}

Kihara

15

_{, Y. Ko}

15

_{, M. Kozai}

17

_,Labaciren

5

_{, G. M. Le}

18

_{, A. F. Li}

19,8,3

_{, H. J. Li}

5

_{, W. J. Li}

3,9

_{,Y.-H. Lin}

3,6

_{, B. Liu}

2

_{, C. Liu}

3

_{, J. S. Liu}

3

_{,M. Y. Liu}

5

_{, W. Liu}

3

_{,Y.-Q. Lou}

20

_,H.Lu

3

_{, X. R. Meng}

5

_{, H. Mitsui1}

4

_{, K. Munakata}

15

_{,H. Nakada}

14

_{, Y.}

Nakamura

3

_{, H. Nanjo}

1

_{, M. Nishizawa}

21

_{, M. Ohnishi}

16

_{,T. Ohura}

14

_{, S. Ozawa}

22

_{, X. L. Qian}

23

_{, X. B. Qu}

24

_{, T. Saito}

25

_{,M. Sakata}

12

_{, T. K. Sako}

16

_{, Y. Sengoku}

14

_{,J. Shao}

3,8

_{, M. hibata}

14

_{,A. Shiomi}

26

_{, H. Sugimoto}

27

_{, W. Takano}

10

_{, M. Takita}

16

_,

Y. H. Tan

3

_{,N. Tateyama}

10

_{,S. Torii}

28

_{, H. Tsuchiya}

29

_{, S. Udo}

10

_{, H. Wang}

3

_{,H. R. Wu}

3

_{, L. Xue}

8

_{, K. Yagisawa}

14

_{, Y. Yamamoto}

12

_{, Z. Yang}

3

_{,Y. Yokoe}

16

_{, A. F. Yuan}

5

_{, L. M. Zhai}

4

_{, H. M. Zhang}

3

_{, J. L. Zhang}

3

_{,X. Zhang}

2

_{, X. Y. Zhang}

8

_{, Y.}

Zhang

3

_{, Yi Zhang}

3

_{,Ying Zhang}

3

_{,S. P. Zhao}

3

_{,Zhaxisangzhu}

5

_{and X. X. Zhou}

9

_{(The Tibet AS𝜸 Collaboration)}

To observe cosmic gamma rays with energies beyond several tens of TeV, a water Cherenkov type muon array (MD) was built under the Tibet air

shower array (Tibet-III). This improved observation experiment containing considerably improved gamma ray sensitivity has been in operation

since 2014. We analyzed gamma rays from Geminga PWNe using data obtained over a period of 720 days from 2014 February to 2017 May using

the Tibet-III air shower array and MD array. Morphological analysis using a two-dimensional map of ray intensity showed strong

gamma-ray emissions from the Geminga region with a significance of 4.0 𝝈 in the energy over 10 TeV, and that the gamma gamma-rays were distributed within

a spread of a few degrees. The extent of the excess region was approximately consistent with the HAWC and the Milagro group results[1,2].

Abstract

Tibet air-shower array and muon-detector array

𝜽

𝟏

Two dimensional map of excess

events around the Geminga area.

Results

Gamma Ray Indirect & Neutrino (074 ) 36th INTERNATIONAL COSMIC RAY CONFERENCE ICRC 2019,

UNIVERSITY OF WISCONSIN-MADISON, MADISON, WISCONSIN, USA

DATA ANALYSIS

The Tibet-III air shower array at Yangbajing Cosmic Ray Observatory

(4300 m a.s.l., 606g/cm

2

_{) in the Tibet, China.}

The current AS array consists of 597 plastic scintillation detectors of

an area 0.5 m

2

_{placed at grid point 7.5 m apart, and its coverage area}

is approximately 65,700 m

2

_.

RoI : Geminga (d<3

o

₎

Dec

.(

deg

)

Number of excess events vs. Distance from the pulsar

1

_{Department of Physics, Hiroaki University, Japan}

2

_{School of Astronomy and Space Science, Nanjing University, China}

3

_{Key Laboratory of Particle Astrophysics, Institute of High Energy Physics,}

Chinese Academy of Sciences, China

4

_{National Astronomical Observatories, Chinese Academy of Sciences, China}

5

_{Physics Department of Science School, Tibet University, China}

6

_{University of Chinese Academy of Sciences, China}

7

_{Department of Physics, Hebei Normal University, China}

8

_{Department of Physics, Shandong University, China}

9

_{Institute of Modern Physics, South West Jiaotong University, China}

10

_{Faculty of Engineering, Kanagawa University, Japan}

11

_{Utsunomiya University, Department of Physics, Konan University, Japan}

13

_{Shibaura Institute of Technology, Japan}

14

_{Faculty of Engineering, Yokohama National University, Japan}

15

_{Department of Physics, Shinshu University, Japan}

16

_{Institute for Cosmic Ray Research, University of Tokyo, Japan}

17

_{ISAS/JAXA, Japan}

18

_{National Center for Space Weather, China Meteorological Administration, China}

19

_{School of Information Science and Engineering, Shandong Agriculture University, China}

20

_{Physics Department, Astronomy Department and Tsinghua Center for Astrophysics,}

Tsinghua-National Astronomical Observatories of China joint Research Center for Astrophysics,

Tsinghua University, China

21

_{National Institute of Informatics, Japan}

22

_{Advanced ICT Research Institute,}

National Institute of Information and Communication Technology, China

23

_{Department of Mechanical and Electrical Engineering, Shandong Management University, China}

24

_{College of Science, China University of Petroleum, China}

25

_{Tokyo Metropolitan College of Industrial Technology, China}

26

_{College of Industrial Technology, Nihon University, Japan}

27

_{Shonan Institute of Technology, Japan}

28

_{Research Institute for Science and Engineering, Waseda University, Japan}

29

_{Japan Atomic Energy Agency, Japan}

Event selection by MD

PMT( HAMAMATSU R3600)

Distribution of the number of muons measured by the MD array

as a function of the sum of particle density measured by the AS array[4].

MC simulation of the Tibet MD shows that the cosmic-ray background events can be

efficiently discriminated from a photon signal by means of counting muon number

in an AS. The cosmic-ray background events are reduced to 1.1% above 10 TeV

with 70% of the photons remaining after the muon cut.

For more than 100TeV, the cosmic ray background event is suppressed 99.92%[4].

The left figure shows

the distribution of the

number of excess

events at each angular

distance as a function of

the angular distance

from the center of the

Geminga. The spread of

the excess area centered

on the Geminga pulsar

was approximated using

a Gaussian function of

𝝈=𝟐.

°

.

Number of signals

:

Correction parameter

of R.A. anisotropy

E> 10 TeV

[1] Abdo, A. A. et al., ApJ, 700, L127 (2009) [3]Kawata, K et al, Exp. Astron. 44, 1 (2017)

[2]Abeysekara, A. et al., Science, 358, 911 (2017) [4]Amenomori, M. et al., PRL., (in press)

(1)

(2)

"Equi-Declination Method", which uses an event in a direction with equal source's

declination but different right ascension. Events in the off-source region(OFF-region) were

used to determine the background, and the OFF-region had the same declination and

angular radius 𝒅 as the on-source region(region). The number of signal events in

ON-region of angular radius 𝒅; 𝑵

_𝒔

𝒅 was calculated using eq. (1).

𝜼 is a correction parameter for the number of background events. The number of events

within a circle of 10 degrees surrounding the disk of angular radius 𝒅 was used to correct

the variation at each right ascension, and the correction parameter was calculated using eq.

(2). An excess of gamma rays was calculated using 𝑵

𝒔

𝒅 and 𝑵

𝒃𝒈

𝒅 , and the

excesses within

°

°

area centered on the Geminga pulsar were estimated.

R.A.(deg)

Measurement of # of m in AS -> g／CR discrimination

DATA: February, 2014 - May, 2017

Live time: 720 days

2.4m underground ( ~ 515g/cm2 ~19X

₀

)

7.35m×7.35m×1.5m deep (water) x 64 units

20” PMT (HAMAMATSU R3600)

Concrete pools + Tyvec sheets

Soil & Rocks 2.6m

Waterproof & reflective materials Reinforced concrete

e

1.0m PMT 7.3m Water 1.5m Cherenkov lights 20 inch Air 0.9m

ü

広がった天体 à HAWCの結果と一致

ü

スペクトル解析中

R.A. (deg.)

Dec. (deg.)

8

10

12

14

16

18

20

22

24

26

-200

0

200

400

600

800

1000

88

90

92

94

96

98

100

102

104

106

108

E > 10 TeV

Smoothed by

3-deg radius circle

MGRO J1908+06

17

R.A. (deg.)

Dec. (deg.)

4

5

6

7

8

-50

0

50

100

150

200

285

286

287

288

289

E > 10 TeV

ü

10TeV 以下で VERITAS の結果と一致

ü

スペクトル解析中

Pulsar

contribution

D. Chen ICRC2019 #648

パルサー解析 ( >10TeV )

18

Search for pulsed gamma-ray emission

in the 100 TeV region from several pulsars

with the Tibet AS+ MD array

M. Amenomori(1), Y.-W. Bao(2), X. J. Bi(3), D. Chen(4), T. L. Chen(5), W. Y. Chen(3), Xu Chen(3), Y. Chen(2), Cirennima(5), S. W. Cui(7), Danzengluobu(5), L. K. Ding(3), J. H. Fang(3,6), K. Fang(3), C. F. Feng(8), Zhaoyang Feng(3), Z. Y. Feng(9), Qi Gao(5), Q. B. Gou(3), Y. Y. Guo(3), Y. Q. Guo(3), H. H. He(3), Z. T. He(7),

K. Hibino(10), N. Hotta(11), Haibing Hu(5), H. B. Hu(3), J. Huang(3), H. Y. Jia(9), L.Jiang(3), H.-B. Jin(4),

F. Kajino(12), K. Kasahara(13), Y. Katayose(14), C. Kato(15), S. Kato(16), K. Kawata(16), W. Kihara(15), Y. Ko(15), M. Kozai(17), Labaciren(5), G. M. Le(18), A. F. Li(19,8,3), H. J. Li(5), W. J. Li(3,9), Y.-H. Lin(3,6), B. Liu(2), C. Liu(3), J. S. Liu(3), M. Y. Liu(5), W. Liu(3), Y.-Q. Lou(20), H.Lu(3), X. R. Meng(5), H. Mitsui(14), K. Munakata(15), H. Nakada(14), Y. Nakamura(3), H. Nanjo(1), M. Nishizawa(21), M. Ohnishi(16), T. Ohura(14), S. Ozawa(22), X. L. Qian(23), X. B. Qu(24), T. Saito(25), M. Sakata(12), T. K. Sako(16), Y. Sengoku(14), J. Shao(3,8), M. Shibata(14), A. Shiomi(26), H. Sugimoto(27), W. Takano(10), M. Takita(16), Y. H. Tan(3), N. Tateyama(10), S. Torii(28), H. Tsuchiya(29), S. Udo(10), H. Wang(3), H. R. Wu(3), L. Xue(8), K. Yagisawa(14), Y. Yamamoto(12), Z. Yang(3), Y. Yokoe(16), A. F. Yuan(5), L. M. Zhai(4), H. M. Zhang(3), J. L. Zhang(3), X. Zhang(2), X. Y. Zhang(8), Y. Zhang(3), Yi Zhang(3), Ying Zhang(3), S. P. Zhao(3), Zhaxisangzhu(5) and X. X. Zhou(9)

(1) Department of Physics, Hirosaki University, Hirosaki 036-8561, Japan

(2) School of Astronomy and Space Science, Nanjing University, Nanjing 210093, China

(3) Key Laboratory of Particle Astrophysics, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China

(4) National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012, China (5) Physics Department of Science School, Tibet University, Lhasa 850000, China

(6) University of Chinese Academy of Sciences, Beijing 100049, China

(7) Department of Physics, Hebei Normal University, Shijiazhuang 050016, China (8) Department of Physics, Shandong University, Jinan 250100, China

(9) Institute of Modern Physics, SouthWest Jiaotong University, Chengdu 610031, China

(10) Faculty of Engineering, Kanagawa University, Yokohama 221-8686, Japan

(11) Utsunomiya University, Utsunomiya 321-8505, Japan

(12) Department of Physics, Konan University, Kobe 658-8501, Japan (13) Shibaura Institute of Technology, Saitama 337-8570, Japan

(14) Faculty of Engineering, Yokohama National University, Yokohama 240-8501, Japan (15) Department of Physics, Shinshu University, Matsumoto 390-8621, Japan

(16) Institute for Cosmic Ray Research, University of Tokyo, Kashiwa 277-8582, Japan

(17) Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency (ISAS/JAXA), Sagamihara 252-5210, Japan

(18) National Center for Space Weather, China Meteorological Administration, Beijing 100081, China (19) School of Information Science and Engineering, Shandong Agriculture University, Taian 271018, China

(20) Physics Department, Astronomy Department and Tsinghua Center for Astrophysics, Tsinghua-National Astronomical Observatories of China joint Research Center for Astrophysics, Tsinghua University, Beijing 100084, China

(21) National Institute of Informatics, Tokyo 101-8430, Japan

(22) Advanced ICT Research Institute, National Institute of Information and Communication Technology, Koganei 184-8795, Japan

(23) Department of Mechanical and Electrical Engineering, Shandong Management University, Jinan 250357, China (24) College of Science, China University of Petroleum, Qingdao, 266555, China

(25) Tokyo Metropolitan College of Industrial Technology, Tokyo 116-8523, Japan (26) College of Industrial Technology, Nihon University, Narashino 275-8576, Japan (27) Shonan Institute of Technology, Fujisawa 251-8511, Japan

(28) Research Institute for Science and Engineering, Waseda University, Tokyo 169-8555, Japan (29) Japan Atomic Energy Agency, Tokai-mura 319-1195, Japan

Tibet ASγ Collaboration

ICRC 2019, Session: Gamma Ray Indirect & Neutrino (ID: 68)

Abstract

We present the results of a search for pulsed gamma-ray emission in the 100 TeV

region from several pulsars using data taken with the Tibet air shower (AS) array

and a water Cherenkov type muon detector (MD) array. The Tibet ASγ experiment

has improved significantly gamma-ray sensitivity by the constructed MD array

since 2014. Based on the observational data with the AS + MD array, we will report

data on several famous pulsars in the northern hemisphere in this presentation.

2. Data Analysis

Figure 2:

(a) Sky Maps of Excess Events,

(b) Distributions of Event Phase,

of the Crab pulsar, Geminga pulsar and

J1907+0602. Phase 0 is defined by the

timing solution derived from the main

pulse of the radio observations.

The arrival time of each event is recorded by a

quartz clock synchronized with GPS, which has

a precision of 1 μs. For the timing analysis, all

the arrival time is converted to the solar system

barycenter frame using the JPL DE405

ephemeris calculated by TEMPO2[4].

Data was analyzed from Feb. 2014 to May

2017 (live time: 720 days).

References

[1] Lyne, A. G., Pritchard, R. S. & Graham-Smith, F. 1993. MNRAS, 265, 100

[2] Abdo, A. A., et al. 2010, ApJ, 720, 272

J1907+0602 [3]

R.A., α (J2000.0)... 19:07:54.74 ±0s.01 Decl., δ (J2000.0)... +06:02:16.9 ±0.3 Pulse frequency, ν (s−1 )... 9.3779822336(4) Frequency first derivative, ν ̇ (s−2 )... −7.63559(2) × 10−12 Frequency second derivative, ν ̈ (s−3) 1.88(7) × 10−22 Epoch of frequency (MJD)... 54935 TZRMJD... 54947.1551911789 Crab Pulsar [1] R.A., α (J2000.0)... 05:34:31.973 ±5.000e-03 Decl., δ (J2000.0)... +22:00:52.06 ±6.000e-02 Pulse frequency, ν (s−1 )... 29.946923

Frequency first derivative, ν ̇ (s−2 )... JBC P Monthly Ephemeris Frequency second derivative, ν ̈ (s−3) JBC P Monthly Ephemeris Epoch of frequency (MJD)... JBC P Monthly Ephemeris TZRMJD... JBC P Monthly Ephemeris

Geminga Pulsar [2]

R.A., α (J2000.0)... 06:33:54.1530 ±2.800e-03 Decl., δ (J2000.0)... +17:46:12.909 ±4.000e-02 Pulse frequency, ν (s−1 )... 4.217639623538 Frequency first derivative, ν ̇ (s−2 )... -1.9515522 × 10−12 Frequency second derivative, ν ̈ (s−3) 0

Epoch of frequency (MJD)... 54800

TZRMJD... 54819.843013078

1. Tibet AS+MD Array

Air Shower (AS) Array

( ~22,050m2, 597 counters)

At Yangbajing in Tibet, China

(90.522˚E, 30.102˚N, 4300 m a.s.l.)

(1) Mode Energy ~ 3 TeV

(2) Angular Resolution ~ 0.9˚ (> 3 TeV)

Muon Detector (MD) Array

(1) 50 m2 x 2 cells 2.5 m underground.

(~90 m away from center of the array)

(2) 1.5 m depth clear water from a well.

(3) 20 inch f PMT x3 for each cell.

(Normal gain x2 and 1/100 gain x1 for test)

(4)The inside of walls and floors are covered

with white epoxy resin or Tyvek sheets.

~99.9% CR rejection

~90% γ efficiency @ 100 TeV

+

||

Figure 1: Configuration of the

tibet AS array and a part of

close-section of the MD.

2. 1. Crab pulsar

_{2. 2. Geminga pulsar}

_{2. 3. J1907+0620}

[3] Abdo, A. A., et al. 2010, ApJ, 711, 64

[4] Hobbs, G., Edwards, R., & Manchester, R. 2006, Chin. J. Astron. Astrophys. Suppl., 6, 189

[5] Ansoldi, S. et al. 2016. A&A 585, A133–6

Fermi-LAT, Ref. [3] Fermi-LAT, Ref. [2]

3. Preliminary Results

Crab nebula, Geminga and J1907+0620 are found steady gamma-ray flux above 10 TeV. But, no significantly pulsed signals are found within almost 0.5

degree radius from position of the pulsar. Search for pulsed gamma-ray emission above 100 TeV regions are currently under analysis.

Background Counts 50 60 70 80 90 100 110 Pulsar Phase 0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 J1907+0602

Tibet

Background Counts 70 80 90 100 110 120 130 Pulsar Phase 0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 Geminga

Tibet

R.A. (deg.) Dec. (deg.) 20 21 22 23 24 -100 0 100 200 300 400 500 600 82 84 86 R.A. (deg.) Dec. (deg.) 4 5 6 7 8 -50 0 50 100 150 200 285 286 287 288 289

(a)

(b)

_(b)

(a)

(b)

Tibet

Tibet

Tibet

Background Counts (>10 T eV) 100 120 140 160 180 200 Pulsar Phase 0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 Crab Pulsar

All data (E > 10TeV)

Preliminary

Preliminary

Preliminary

_Preliminary

_Preliminary

MAGIC, Ref. [5] R.A. (deg.) Dec. (deg.) 8 10 12 14 16 18 20 22 24 26 -200 0 200 400 600 800 1000 88 90 92 94 96 98 100 102 104 106 108

Preliminary

All data (E > 10TeV) _{All data (E> 10TeV)}

(a)

Tibet

ü

優位な信号は見つからず

ü

100 TeV 領域解析中

Crab pulsar

Geminga pulsar

PSR J1907+0602

Knee領域一次宇宙線組成の研究

経過報告

・

YAC-II観測実験：[⽬的]100 TeV以上のエネルギー領域の陽⼦、ヘリウムスペクトル

2014年度からの観測を継続中

（将来計画）

・

YAC-III観測実験：[⽬的] 10

16

_{eV領域での重原⼦核成分}

モンテカルトスタディーの精密化、読み出し回路開発、光センサー試験

YAC-II

Total : 124 YAC detectors

Cover area: ～ 500 m

2

本年度の発表・論文等

・ ICRC2019 4件

p+Heスペクトル

Liuming Zhai, “Primary Cosmic-ray Spectra and Composition in the Energy Range of 50 TeV-10

16

_{eV with the New Tibet Hybrid}

Experiment (YAC-II + Tibet-III + MD)”

J. Huang, "Hadronic interactions and EAS muon multiplicity investigated with the new Tibet hybrid experimental muon data”

Y. Zhang, "Test of hadronic interaction models in the forward region from 10 TeV to 1 PeV with the new Tibet EAS core data"

Y. Zhang, "Study of the sharp "knee" phenomenon of cosmic ray spectrum by using newly upgraded Tibet ASγ experiment

“

ü

Tibet-III (>3TeV)

2000年-2009年(10年間)

ü

太陽方向を中心にした4 4 の欠損率マップ

20

宇宙線による太陽の影を用いた太陽周辺磁場の

時間変動の研究

4. Magnetic Field Model

For the solar magnetic field model in the MC simulation, we

adopt the CSSS model which is the potential field model most

successfully reproducing the temporal variation of the Sun’s

shadow observed with Tibet-II at 10 TeV (Amenomori

et al.

2013

). The potential field models describe the coronal

magnetic field based on the optical measurements of the

photospheric magnetic field. In our MC simulations, we use the

photospheric field observed with the spectromagnetograph of

the National Solar Observatory at Kitt Peak (Jones et al.

1992

)

in each Carrington rotation (CR) period (∼27.3 days). The

CSSS model (Zhao & Hoeksema

1995

) involves four free

parameters, the radius R

ss

of the spherical source surface (SS)

where the supersonic solar wind starts blowing radially, the

order n of the spherical harmonic series describing the observed

photospheric field, the radius R

cp

(=1.7 R

e

) of the sphere

where the magnetic cusp structure in the helmet streamers

appears, and the length scale l

a

of horizontal coronal electric

currents. In the present paper, we set l

a

to be one solar radius

(l

a

=R

e

) and examine two different cases with R

ss

=2.5 R

e

and R

ss

=10 R

e

. The former R

ss

is a standard value used in the

original paper (Zhao & Hoeksema

1995

), while the latter

gained support from some recent evidences (Balogh et al.

1995

;

Zhao et al.

2002

; Schüssler & Baumannk

2006

). We set n=10

which is sufficient to describe fine structures relevant to the

orbital motion of high-energy particles with large Larmor radii.

The radial component of the coronal magnetic field at R

ss

is

then stretched out forming the Parker’s spiral interplanetary

magnetic field (IMF; Parker

1958

). For the radial solar wind

speed needed in the Parker’s model, we use the solar wind

speed synoptic chart estimated from the interplanetary

scintillation measurement in each CR and averaged over the

Carrington longitude (Tokumaru et al.

2010

).

27

_{We adopt a}

dipole model for the geomagnetic field.

Figure 1. Year-to-year variation of (a) the Sun’s shadow and (b) Moon’s shadow observed by the Tibet-III array between 2000 and 2009. The upper panels show 2D contour maps of Dobsin the Sun’s shadow in the GSE coordinate system, while the lower panels display Dobsin the Moon’s shadow each as a function of right

ascension and declination relative to the apparent center of the Moon.

27_{http://stsw1.isee.nagoya-u.ac.jp/ips_data-e.html}

3

The Astrophysical Journal, 860:13 (7pp), 2018 June 10 Amenomori et al.

太陽の影

à太陽コロナ磁場

の影響で変動

⽉の影

Amenomori et al., ApJ, 860,13 (2018)

「太陽の影」

地球

TeV宇宙線（陽子）

à荷電粒子

ラーモア半径

～7.4AU

(B=30

µG 地球近辺)

～0.16R

_☉

(B=300mG 太陽近辺)

à 太陽磁場構造のプローブ！

太陽による宇宙線の遮蔽

太

陽

太陽表面:

光学望遠鏡観測

(ゼーマン効果)

@1AU

衛星観測

モデルによる推定

21

「太陽の影」の

深さ、⽅向、形

に影響

中村佳昭他、

2019年9⽉⽇本物理学会

Y. Nakamura, ICRC2019：Can we estimate the variation of the z-component of the

interplanetary magnetic field from the sun shadow?

太陽の影からコロナ磁場、惑星間空間磁場のモデルの評価が可能

P.22

CME(コロナ質量放出)の影響

Amenomori et al, 2013,2018,PRL

Amenomori et al,2018,ApJ

Su

n

Sp

ot

Nu

m

be

r

De

fic

it

ra

te

D(

%

)

Black :Experimental

Red : MC with best

magneCc field model

CME effect

Coronal magnetic

field effect

IMF effect

先⾏研究

実際の磁場強度はモデル予測より

1.5倍ほど⼤きい

CSSSモデル Rss=10R

◉

のモデルで観測をよく再現

CMEの影響により影が薄くなる

CMEの模式図

(Richardson &Cane 2010)

CME effect

影の深さの変化 全期間 - 3 TeV

P.23

惑星間空間磁場

(IMF)の

z 成分が負(南向き)

に卓越

地磁気とのリコネクション

NICT:http://swc.nict.go.jp/knowledge/magnetosphere.html

地磁気嵐に伴う障害

•

GPSの誤差増⼤

• 電波障害

• ⾼⾼度での放射線被曝

• 送電網の破損

地磁気嵐の誘発

CR1962(2000.4.19-2000.5.16)

CME通過期間

地球近傍での観測結果

磁場モデルの予測

太陽⾵

速度

[km

/s]

IMF

強度

[nT

]

IMF

B

x

[nT

]

IMF

B

y

[nT

]

IMF

B

z

[nT

]

Kp

ind

ex

Bzの変動と地磁気嵐

MJD

惑星間空間磁場

(IMF)の

z 成分が負(南向き)

に卓越

地磁気とのリコネクション

P.24

NICT:http://swc.nict.go.jp/knowledge/magnetosphere.html

地磁気嵐に伴う障害

•

GPSの誤差増⼤

• 電波障害

• ⾼⾼度での放射線被曝

• 送電網の破損

MJD

CR2006(2003.8.2-2003.8.30)

CME通過期間

地球近傍での観測結果

磁場モデルの予測

太陽⾵

速度

[km

/s]

IMF

強度

[nT

]

IMF

B

x

[nT

]

IMF

B

y

[nT

]

IMF

B

z

[nT

]

Kp

ind

ex

地磁気嵐の誘発

太陽の影

から

_B

_z

の推定

_=>

_B

_z

が地球に

到来する前に

推定が可能

まずは

B

_z

と

太陽の影の東⻄⽅向のずれ

の相関を調べる

宇宙天気の新しいツール

本研究の⽬的

Bzの変動と地磁気嵐

太陽の影の東⻄⽅向のずれ その他の原因

P.25

P.25

⾚

:MC Bx1.0

⻘

:MC コロナx1.5

⾚紫

:MC コロナなし

緑

:MC IMFx1.5

1. 地磁気 0.15度程度(@10TV)

⽉の影で観測可

3. Parker磁場の y成分からの寄与

太陽の⾃転軸の傾きに由来する

Bzの季節変動

=>半年の観測ではセクター依存性

これらの変動は

MCで再現可能

Amenomiri et al. PRL 2018

We

st

Δd

EW

[d

eg

re

e]

E

as

t

We

st

Δd

EW

[d

eg

re

e]

E

as

t

We

st

Δd

EW

[d

eg

re

e]

E

as

t

IM

F B

y

[nT

]

IM

F

B

z

[nT

]

2008.3-2008.8

0.5AUでの3⽇間平均

磁場モデルの予測

y成分からの寄与

⽉の影の

東⻄⽅向のずれ

太陽の影の

MC

太陽の影の東⻄⽅向のずれ

Away

Toward

MC

と観測の差

<=>

Bz 成分

の寄与

2. コロナ磁場のdipole成分 0.05度程度

2000-2009 -> 地磁気と同じ向き

使⽤したデータ

P.26

観測

MC

期間

: 2000

- 2009 (3⽉から8⽉)

天頂⾓

: 40度以下

1.25 粒⼦以上を4台以上で検出

Σρ (粒⼦数密度の総和)＞31.6以上で5分割

磁場モデル

コロナ:

Current Sheet Source Surface (CSSS)モデル

IMF:

Parker磁場

地磁気:

dipole

光球⾯磁場データ；

Kitt Peak 太陽望遠鏡

※

_{全体の磁場強度}

_1.5倍

0.5AUでの

Bz

の変動でデータを分割

Σρ

event数

平均

Rigidity [TV]

31.6~56.2

1.3x10

7

6TV

56.2~100

7.2x10

6

8TV

100~215

4.3x10

6

13TV

215~464

1.4x10

6

20TV

464.2~

6.3x10

5

50TV

DATASET NAME

-2

-1

0

1

2

Bz Condition

Bz＜-0.8 [nT]

-0.8<Bz<0.2 [nT]

-0.2<Bz<0.2 [nT]

0.2<Bz<0.8 [nT]

0.8<Bz [nT]

平均 Bz [nT]

-1.638 ± 0.024

-0.444 ± 0.004

-0.003 ± 0.002

0.431 ± 0.003

1.524 ± 0.024

総イベント数

3.5x10

6

_6.5x10

6

_6.9x10

6

_6.5x10

6

_3.1x10

6

10TeVでのズレ α のBz 依存性

P.27

⿊：南北⽅向のずれ

No

rt

h

So

uth

Di

sp

la

ce

m

en

t

An

gl

e

@

10T

V

North

South

IMF B

_z

⼀次直線でフィッティング

α

EW

=（-0.09±0.04)*B

z

IMF

+(-0.20 ± 0.02 )

α

EW

=（-0.00±0.01)*B

z

IMF

+(-0.226 ± 0.007)

Black ::Observed

Red :: MC B x 1.5

傾きの差

2.1 σ (統計誤差のみ)

We

st

Ea

st

MCの南北のズレ

東⻄のズレ

南北のズレ

観測の南北のズレ

MCに含まれない(突発的な)

IMF Bz 変動

によって

太陽の影の東⻄のズ

レ

が変化することを⽰唆

まとめ

1. Tibet AS+MD

•

かに星雲から史上最高エネルギーのガンマ線を観測

（最大エネルギー450TeV、新しいガンマ線観測手法の成果）

•

>100TeV領域の天文学を開拓

•

SNR G106.3+27, Geminga, MGRO J1908+06からの>10TeV

ガンマ線を観測（さらに解析中）

2. YAC

•

YAC-II ：2014年から観測を継続中、ＭＤデータも含め解析中

•

YAC-III （将来計画）モンテカルロスタディの精密化、読み出し

回路開発、光センサー試験中

3. 太陽の影

•

影の東西方向のズレとIMFの解析

à

IMFのBz成分と相関あるが、MCとは2.1σずれあり

à

MCに含めなかったIMF Bz変動がズレに影響している可能性

を示唆する初めての結果

4. 宇宙線異方性

(宗像、12/13発表参照)

28