又一个太阳之谜：太阳盘GeV辐射的意外不对称性
Yet Another Sunshine Mystery: Unexpected Asymmetry in GeV Emission from the Solar Disk
AI总结：
本文利用费米望远镜14年数据，通过日面投影和时间相关形态分析，发现太阳盘GeV辐射存在与太阳活动周及极区磁场翻转相关的能量依赖不对称性，挑战了现有发射模型。
摘要：
太阳是天空中最明亮的γ射线源之一，并持续挑战我们对其高能发射机制的理解。本研究利用费米大视场望远镜在2008年8月至2022年1月期间的数据，对太阳盘γ射线发射进行了深入调查。我们重点关注能量超过5 GeV、来自以太阳为中心的0.5°角孔径内的γ射线事件，并实施严格的时间截断以尽量减少潜在的样本污染。我们使用日面投影方法相对于太阳自转轴解析γ射线事件，并结合统计检验来研究事件在太阳盘上的分布。我们发现，在大时间窗口上积分观测可能会忽略相关的不对称特征，而我们在本工作中通过精细的时间相关形态分析揭示了这些特征。我们描述了显著的各向异性趋势，并确认了太阳盘γ射线发射中能量依赖不对称性的有力证据。有趣的是，不对称特征与第24太阳活动周极大期（约2014年6月）太阳极区磁场翻转的时间相吻合。我们的发现表明，太阳的磁位形在塑造最终γ射线特征中起着重要作用，突显了观测到的各向异性、太阳活动周和太阳磁场之间的潜在联系。这些见解对已有的发射模型提出了重大挑战，为高能太阳天体物理学带来了新的视角。
英文摘要：
The Sun is one of the most luminous $γ$-ray sources in the sky and continues to challenge our understanding of its high-energy emission mechanisms. This study provides an in-depth investigation of the solar disk $γ$-ray emission, using data from the Fermi Large Area Telescope spanning 2008 August to 2022 January. We focus on $γ$-ray events with energies exceeding 5 GeV, originating from 0.5$^\circ$ angular aperture centered on the Sun, and implement stringent time cuts to minimize potential sample contaminants. We use a helioprojection method to resolve the $γ$-ray events relative to the solar rotation axes and combine statistical tests to investigate the distribution of events over the solar disk. We found that integrating observations over large time windows may overlook relevant asymmetrical features, which we reveal in this work through a refined time-dependent morphological analysis. We describe significant anisotropic trends and confirm compelling evidence of energy-dependent asymmetry in the solar disk $γ$-ray emission. Intriguingly, the asymmetric signature coincides with the Sun's polar field flip during the cycle 24 solar maximum, around 2014 June. Our findings suggest that the Sun's magnetic configuration plays a significant role in shaping the resulting $γ$-ray signature, highlighting a potential link between the observed anisotropies, solar cycle, and the solar magnetic fields. These insights pose substantial challenges to established emission models, prompting fresh perspectives on high-energy solar astrophysics.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
