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Linden T, Zhou B, Beacom JF, Peter AHG, Ng KCY, Tang QW. Evidence for a New Component of High-Energy Solar Gamma-Ray Production. Phys Rev Lett 2018; 121:131103. [PMID: 30312037 DOI: 10.1103/physrevlett.121.131103] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2018] [Revised: 07/23/2018] [Indexed: 06/08/2023]
Abstract
The observed multi-GeV γ-ray emission from the solar disk-sourced by hadronic cosmic rays interacting with gas and affected by complex magnetic fields-is not understood. Utilizing an improved analysis of the Fermi-LAT data that includes the first resolved imaging of the disk, we find strong evidence that this emission is produced by two separate mechanisms. Between 2010 and 2017 (the rise to and fall from solar maximum), the γ-ray emission was dominated by a polar component. Between 2008 and 2009 (solar minimum) this component remained present, but the total emission was instead dominated by a new equatorial component with a brighter flux and harder spectrum. Most strikingly, although six γ rays above 100 GeV were observed during the 1.4 yr of solar minimum, none were observed during the next 7.8 yr. These features, along with a 30-50 GeV spectral dip which will be discussed in a companion paper, were not anticipated by theory. To understand the underlying physics, Fermi-LAT and HAWC observations of the imminent cycle 25 solar minimum are crucial.
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Affiliation(s)
- Tim Linden
- Center for Cosmology and AstroParticle Physics (CCAPP), The Ohio State University, Columbus, Ohio 43210, USA
| | - Bei Zhou
- Center for Cosmology and AstroParticle Physics (CCAPP), The Ohio State University, Columbus, Ohio 43210, USA
- Department of Physics, The Ohio State University, Columbus, Ohio 43210, USA
| | - John F Beacom
- Center for Cosmology and AstroParticle Physics (CCAPP), The Ohio State University, Columbus, Ohio 43210, USA
- Department of Physics, The Ohio State University, Columbus, Ohio 43210, USA
- Department of Astronomy, The Ohio State University, Columbus, Ohio 43210, USA
| | - Annika H G Peter
- Center for Cosmology and AstroParticle Physics (CCAPP), The Ohio State University, Columbus, Ohio 43210, USA
- Department of Physics, The Ohio State University, Columbus, Ohio 43210, USA
- Department of Astronomy, The Ohio State University, Columbus, Ohio 43210, USA
| | - Kenny C Y Ng
- Department of Particle Physics and Astrophysics, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Qing-Wen Tang
- Center for Cosmology and AstroParticle Physics (CCAPP), The Ohio State University, Columbus, Ohio 43210, USA
- Department of Physics, Nanchang University, Nanchang 330031, China
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Amenomori M, Bi XJ, Chen D, Chen TL, Chen WY, Cui SW, Ding LK, Feng CF, Feng Z, Feng ZY, Gou QB, Guo YQ, He HH, He ZT, Hibino K, Hotta N, Hu H, Hu HB, Huang J, Jia HY, Jiang L, Kajino F, Kasahara K, Katayose Y, Kato C, Kawata K, Kozai M, Le GM, Li AF, Li HJ, Li WJ, Liu C, Liu JS, Liu MY, Lu H, Meng XR, Miyazaki T, Mizutani K, Munakata K, Nakajima T, Nakamura Y, Nanjo H, Nishizawa M, Niwa T, Ohnishi M, Ohta I, Ozawa S, Qian XL, Qu XB, Saito T, Saito TY, Sakata M, Sako TK, Shao J, Shibata M, Shiomi A, Shirai T, Sugimoto H, Takita M, Tan YH, Tateyama N, Torii S, Tsuchiya H, Udo S, Wang H, Wu HR, Xue L, Yamamoto Y, Yamauchi K, Yang Z, Yuan AF, Yuda T, Zhai LM, Zhang HM, Zhang JL, Zhang XY, Zhang Y, Zhang Y, Zhang Y, Zhou XX. Evaluation of the Interplanetary Magnetic Field Strength Using the Cosmic-Ray Shadow of the Sun. Phys Rev Lett 2018; 120:031101. [PMID: 29400499 DOI: 10.1103/physrevlett.120.031101] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/25/2017] [Indexed: 06/07/2023]
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.
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Affiliation(s)
- M Amenomori
- Department of Physics, Hirosaki University, Hirosaki 036-8561, Japan
| | - X J Bi
- Key Laboratory of Particle Astrophysics, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China
| | - D Chen
- National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012, China
| | - T L Chen
- Department of Mathematics and Physics, Tibet University, Lhasa 850000, China
| | - W Y Chen
- Key Laboratory of Particle Astrophysics, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China
| | - S W Cui
- Department of Physics, Hebei Normal University, Shijiazhuang 050016, China
| | - L K Ding
- Key Laboratory of Particle Astrophysics, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China
| | - C F Feng
- Department of Physics, Shandong University, Jinan 250100, China
| | - Zhaoyang Feng
- Key Laboratory of Particle Astrophysics, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China
| | - Z Y Feng
- Institute of Modern Physics, SouthWest Jiaotong University, Chengdu 610031, China
| | - Q B Gou
- Key Laboratory of Particle Astrophysics, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China
| | - Y Q Guo
- Key Laboratory of Particle Astrophysics, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China
| | - H H He
- Key Laboratory of Particle Astrophysics, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China
| | - Z T He
- Department of Physics, Hebei Normal University, Shijiazhuang 050016, China
| | - K Hibino
- Faculty of Engineering, Kanagawa University, Yokohama 221-8686, Japan
| | - N Hotta
- Faculty of Education, Utsunomiya University, Utsunomiya 321-8505, Japan
| | - Haibing Hu
- Department of Mathematics and Physics, Tibet University, Lhasa 850000, China
| | - H B Hu
- Key Laboratory of Particle Astrophysics, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China
| | - J Huang
- Key Laboratory of Particle Astrophysics, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China
| | - H Y Jia
- Institute of Modern Physics, SouthWest Jiaotong University, Chengdu 610031, China
| | - L Jiang
- Key Laboratory of Particle Astrophysics, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China
| | - F Kajino
- Department of Physics, Konan University, Kobe 658-8501, Japan
| | - K Kasahara
- Research Institute for Science and Engineering, Waseda University, Tokyo 169-8555, Japan
| | - Y Katayose
- Faculty of Engineering, Yokohama National University, Yokohama 240-8501, Japan
| | - C Kato
- Department of Physics, Shinshu University, Matsumoto 390-8621, Japan
| | - K Kawata
- Institute for Cosmic Ray Research, University of Tokyo, Kashiwa 277-8582, Japan
| | - M Kozai
- Department of Physics, Shinshu University, Matsumoto 390-8621, Japan
- Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency (ISAS/JAXA), Sagamihara, Kanagawa 252-5210, Japan
| | - G M Le
- National Center for Space Weather, China Meteorological Administration, Beijing 100081, China
| | - A F Li
- Key Laboratory of Particle Astrophysics, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China
- Department of Physics, Shandong University, Jinan 250100, China
- School of Information Science and Engineering, Shandong Agriculture University, Taian 271018, China
| | - H J Li
- Department of Mathematics and Physics, Tibet University, Lhasa 850000, China
| | - W J Li
- Key Laboratory of Particle Astrophysics, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China
- Institute of Modern Physics, SouthWest Jiaotong University, Chengdu 610031, China
| | - C Liu
- Key Laboratory of Particle Astrophysics, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China
| | - J S Liu
- Key Laboratory of Particle Astrophysics, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China
| | - M Y Liu
- Department of Mathematics and Physics, Tibet University, Lhasa 850000, China
| | - H Lu
- Key Laboratory of Particle Astrophysics, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China
| | - X R Meng
- Department of Mathematics and Physics, Tibet University, Lhasa 850000, China
| | - T Miyazaki
- Department of Physics, Shinshu University, Matsumoto 390-8621, Japan
| | - K Mizutani
- Research Institute for Science and Engineering, Waseda University, Tokyo 169-8555, Japan
- Saitama University, Saitama 338-8570, Japan
| | - K Munakata
- Department of Physics, Shinshu University, Matsumoto 390-8621, Japan
| | - T Nakajima
- Department of Physics, Shinshu University, Matsumoto 390-8621, Japan
| | - Y Nakamura
- Department of Physics, Shinshu University, Matsumoto 390-8621, Japan
| | - H Nanjo
- Department of Physics, Hirosaki University, Hirosaki 036-8561, Japan
| | - M Nishizawa
- National Institute of Informatics, Tokyo 101-8430, Japan
| | - T Niwa
- Department of Physics, Shinshu University, Matsumoto 390-8621, Japan
| | - M Ohnishi
- Institute for Cosmic Ray Research, University of Tokyo, Kashiwa 277-8582, Japan
| | - I Ohta
- Sakushin Gakuin University, Utsunomiya 321-3295, Japan
| | - S Ozawa
- Research Institute for Science and Engineering, Waseda University, Tokyo 169-8555, Japan
| | - X L Qian
- Key Laboratory of Particle Astrophysics, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China
- Department of Physics, Shandong University, Jinan 250100, China
| | - X B Qu
- College of Science, China University of Petroleum, Qingdao 266555, China
| | - T Saito
- Tokyo Metropolitan College of Industrial Technology, Tokyo 116-8523, Japan
| | - T Y Saito
- Max-Planck-Institut für Physik, München D-80805, Deutschland
| | - M Sakata
- Department of Physics, Konan University, Kobe 658-8501, Japan
| | - T K Sako
- Institute for Cosmic Ray Research, University of Tokyo, Kashiwa 277-8582, Japan
- Escuela de Ciencias Físicas y Nanotechnología, Yachay Tech, Imbabura 100115, Ecuador
| | - J Shao
- Key Laboratory of Particle Astrophysics, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China
- Department of Physics, Shandong University, Jinan 250100, China
| | - M Shibata
- Faculty of Engineering, Yokohama National University, Yokohama 240-8501, Japan
| | - A Shiomi
- College of Industrial Technology, Nihon University, Narashino 275-8576, Japan
| | - T Shirai
- Faculty of Engineering, Kanagawa University, Yokohama 221-8686, Japan
| | - H Sugimoto
- Shonan Institute of Technology, Fujisawa 251-8511, Japan
| | - M Takita
- Institute for Cosmic Ray Research, University of Tokyo, Kashiwa 277-8582, Japan
| | - Y H Tan
- Key Laboratory of Particle Astrophysics, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China
| | - N Tateyama
- Faculty of Engineering, Kanagawa University, Yokohama 221-8686, Japan
| | - S Torii
- Research Institute for Science and Engineering, Waseda University, Tokyo 169-8555, Japan
| | - H Tsuchiya
- Japan Atomic Energy Agency, Tokai-mura 319-1195, Japan
| | - S Udo
- Faculty of Engineering, Kanagawa University, Yokohama 221-8686, Japan
| | - H Wang
- Key Laboratory of Particle Astrophysics, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China
| | - H R Wu
- Key Laboratory of Particle Astrophysics, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China
| | - L Xue
- Department of Physics, Shandong University, Jinan 250100, China
| | - Y Yamamoto
- Department of Physics, Konan University, Kobe 658-8501, Japan
| | - K Yamauchi
- Faculty of Engineering, Yokohama National University, Yokohama 240-8501, Japan
| | - Z Yang
- Key Laboratory of Particle Astrophysics, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China
| | - A F Yuan
- Department of Mathematics and Physics, Tibet University, Lhasa 850000, China
| | - T Yuda
- Institute for Cosmic Ray Research, University of Tokyo, Kashiwa 277-8582, Japan
| | - L M Zhai
- National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012, China
| | - H M Zhang
- Key Laboratory of Particle Astrophysics, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China
| | - J L Zhang
- Key Laboratory of Particle Astrophysics, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China
| | - X Y Zhang
- Department of Physics, Shandong University, Jinan 250100, China
| | - Y Zhang
- Key Laboratory of Particle Astrophysics, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China
| | - Yi Zhang
- Key Laboratory of Particle Astrophysics, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China
| | - Ying Zhang
- Key Laboratory of Particle Astrophysics, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China
| | - X X Zhou
- Institute of Modern Physics, SouthWest Jiaotong University, Chengdu 610031, China
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