Evaluation of the Interplanetary Magnetic Field Strength Using the Cosmic-Ray Shadow of the Sun

M Amenomori; X J Bi; D Chen; T L Chen; W Y Chen; S W Cui; Danzengluobu; L K Ding; C F Feng; Zhaoyang Feng; Z Y Feng; Q B Gou; Y Q Guo; H H He; Z T He; K Hibino; N Hotta; Haibing Hu; H B Hu; J Huang; H Y Jia; L Jiang; F Kajino; K Kasahara; Y Katayose; C Kato; K Kawata; M Kozai; Labaciren; G M Le; A F Li; H J Li; W J Li; C Liu; J S Liu; M Y Liu; H Lu; X R Meng; T Miyazaki; K Mizutani; K Munakata; T Nakajima; Y Nakamura; H Nanjo; M Nishizawa; T Niwa; M Ohnishi; I Ohta; S Ozawa; X L Qian; X B Qu; T Saito; T Y Saito; M Sakata; T K Sako; J Shao; M Shibata; A Shiomi; T Shirai; H Sugimoto; M Takita; Y H Tan; N Tateyama; S Torii; H Tsuchiya; S Udo; H Wang; H R Wu; L Xue; Y Yamamoto; K Yamauchi; Z Yang; A F Yuan; T Yuda; L M Zhai; H M Zhang; J L Zhang; X Y Zhang; Y Zhang; Yi Zhang; Ying Zhang; Zhaxisangzhu; X X Zhou; Tibet ASγ Collaboration

doi:10.1103/PhysRevLett.120.031101

Evaluation of the Interplanetary Magnetic Field Strength Using the Cosmic-Ray Shadow of the Sun

Phys Rev Lett. 2018 Jan 19;120(3):031101. doi: 10.1103/PhysRevLett.120.031101.

Authors

M Amenomori¹, X J Bi², D Chen³, T L Chen⁴, W Y Chen², S W Cui⁵, Danzengluobu⁴, L K Ding², C F Feng⁶, Zhaoyang Feng², Z Y Feng⁷, Q B Gou², Y Q Guo², H H He², Z T He⁵, K Hibino⁸, N Hotta⁹, Haibing Hu⁴, H B Hu², J Huang², H Y Jia⁷, L Jiang², F Kajino¹⁰, K Kasahara¹¹, Y Katayose¹², C Kato¹³, K Kawata¹⁴, M Kozai^{13

15}, Labaciren⁴, G M Le¹⁶, A F Li^{2

6

17}, H J Li⁴, W J Li^{2

7}, C Liu², J S Liu², M Y Liu⁴, H Lu², X R Meng⁴, T Miyazaki¹³, K Mizutani^{11

18}, K Munakata¹³, T Nakajima¹³, Y Nakamura¹³, H Nanjo¹, M Nishizawa¹⁹, T Niwa¹³, M Ohnishi¹⁴, I Ohta²⁰, S Ozawa¹¹, X L Qian^{2

6}, X B Qu²¹, T Saito²², T Y Saito²³, M Sakata¹⁰, T K Sako^{14

24}, J Shao^{2

6}, M Shibata¹², A Shiomi²⁵, T Shirai⁸, H Sugimoto²⁶, M Takita¹⁴, Y H Tan², N Tateyama⁸, S Torii¹¹, H Tsuchiya²⁷, S Udo⁸, H Wang², H R Wu², L Xue⁶, Y Yamamoto¹⁰, K Yamauchi¹², Z Yang², A F Yuan⁴, T Yuda¹⁴, L M Zhai³, H M Zhang², J L Zhang², X Y Zhang⁶, Y Zhang², Yi Zhang², Ying Zhang², Zhaxisangzhu⁴, X X Zhou⁷; Tibet ASγ Collaboration

Affiliations

¹ Department of Physics, Hirosaki University, Hirosaki 036-8561, Japan.
² Key Laboratory of Particle Astrophysics, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China.
³ National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012, China.
⁴ Department of Mathematics and Physics, Tibet University, Lhasa 850000, China.
⁵ Department of Physics, Hebei Normal University, Shijiazhuang 050016, China.
⁶ Department of Physics, Shandong University, Jinan 250100, China.
⁷ Institute of Modern Physics, SouthWest Jiaotong University, Chengdu 610031, China.
⁸ Faculty of Engineering, Kanagawa University, Yokohama 221-8686, Japan.
⁹ Faculty of Education, Utsunomiya University, Utsunomiya 321-8505, Japan.
¹⁰ Department of Physics, Konan University, Kobe 658-8501, Japan.
¹¹ Research Institute for Science and Engineering, Waseda University, Tokyo 169-8555, Japan.
¹² Faculty of Engineering, Yokohama National University, Yokohama 240-8501, Japan.
¹³ Department of Physics, Shinshu University, Matsumoto 390-8621, Japan.
¹⁴ Institute for Cosmic Ray Research, University of Tokyo, Kashiwa 277-8582, Japan.
¹⁵ Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency (ISAS/JAXA), Sagamihara, Kanagawa 252-5210, Japan.
¹⁶ National Center for Space Weather, China Meteorological Administration, Beijing 100081, China.
¹⁷ School of Information Science and Engineering, Shandong Agriculture University, Taian 271018, China.
¹⁸ Saitama University, Saitama 338-8570, Japan.
¹⁹ National Institute of Informatics, Tokyo 101-8430, Japan.
²⁰ Sakushin Gakuin University, Utsunomiya 321-3295, Japan.
²¹ College of Science, China University of Petroleum, Qingdao 266555, China.
²² Tokyo Metropolitan College of Industrial Technology, Tokyo 116-8523, Japan.
²³ Max-Planck-Institut für Physik, München D-80805, Deutschland.
²⁴ Escuela de Ciencias Físicas y Nanotechnología, Yachay Tech, Imbabura 100115, Ecuador.
²⁵ College of Industrial Technology, Nihon University, Narashino 275-8576, Japan.
²⁶ Shonan Institute of Technology, Fujisawa 251-8511, Japan.
²⁷ Japan Atomic Energy Agency, Tokai-mura 319-1195, Japan.

PMID: 29400499
DOI: 10.1103/PhysRevLett.120.031101

Abstract

We analyze the Sun's shadow observed with the Tibet-III air shower array and find that the shadow's center deviates northward (southward) from the optical solar disk center in the "away" ("toward") interplanetary magnetic field (IMF) sector. By comparing with numerical simulations based on the solar magnetic field model, we find that the average IMF strength in the away (toward) sector is 1.54±0.21_{stat}±0.20_{syst} (1.62±0.15_{stat}±0.22_{syst}) times larger than the model prediction. These demonstrate that the observed Sun's shadow is a useful tool for the quantitative evaluation of the average solar magnetic field.