报告题目：TeV Solar Gamma Rays From Cosmic-Ray Interactions

　　报告人：周贝(Center of Cosmology and AstroParticle Physics, Ohio State University)

　　报告摘要：The Sun is a bright source of GeV gamma rays, due to cosmic rays interacting with solar matter and photons. Key aspects of the underlying processes remain mysterious. The emission in the TeV range, for which there are neither observational nor theoretical studies, could provide crucial clues. The new experiments HAWC (running) and LHAASO (planned) can look with unprecedented sensitivity. In this paper, we predict the very high energy (up to 1000 TeV) gamma-ray flux from the solar disk and halo, due to cosmic-ray hadrons and electrons, respectively. We neglect solar magnetic effects, which is valid at TeV energies; at lower energies, this gives a theoretical lower bound on the disk flux and a theoretical upper bound on the halo flux. We show that the solar-halo gamma-ray flux allows the first test of the ~ 5--70 TeV cosmic-ray electron spectrum. Further, we show HAWC can immediately make an even stronger test with non-directional observations of electron cosmic rays. Together, these gamma-ray and electron studies will provide new insights about the local density of cosmic rays and their interactions with the Sun and its magnetic environment. These studies will also be an important input to tests of new physics, including dark matter.

　　报告时间：2016年12月15日 星期四 下午 3:00

　　报告地点：（北京西路2号）紫台大楼317会议室

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　                                            　紫金山天文台学术委员会