发表机构
Queen’s University Belfast; University of Oslo; California State University Northridge; ASI Italian Space Agency; ESA Science and Operations Department; Northumbria University; Institute of Theoretical Astrophysics（贝尔法斯特女王大学; 奥斯陆大学; 北岭加州州立大学; 意大利航天局; 欧洲空间局科学与运营部; 诺森比亚大学; 理论天体物理研究所）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究发现太阳色球磁冠拓扑结构会调制视场平均的三分钟振荡功率，密集连续磁冠可大幅降低该功率，为解释色球振荡功率提供了实用判据。
AI 中文摘要
三分钟（~5 mHz）振荡是太阳色球层中波传播的显著特征，但在全日盘观测与小视场高分辨率观测中，测得的功率存在显著差异。本研究探究色球磁冠拓扑结构，尤其是其横向连续性和面积填充率，是否会调制视场平均的三分钟功率。我们分析瑞典1米太阳望远镜的Hα和Ca II 8542 Å光谱成像数据，对比少冠的宁静太阳场景与多冠的活动区环境，并辅以少冠和多冠大气的辐射磁流体动力学Bifrost模拟。我们计算观测中固定波长强度和由 bisector 导出的速度的视场平均功率谱，以及模拟中合成强度、速度和温度 proxy 的视场平均功率谱。我们还利用基于HMI的磁场外推方法，量化了3-5 mHz超额功率积分与冠填充因子之间的关系。在观测和模拟中，少冠场景均呈现明显的3-5 mHz功率增强，而多冠场景的测得功率则显著降低。该趋势在Hα和Ca II 8542 Å强度中均存在，并得到速度和温度 proxy 的补充支持。3-5 mHz超额功率积分随冠填充因子的增加而降低。我们得出结论，色球视场平均的三分钟功率是一种拓扑加权可观测量：密集、横向连续的磁冠可大幅降低测得的大规模三分钟信号，而无需局部波活动缺失。这为将色球振荡功率解释为太阳及磁化冷恒星大气中的大气波能 proxy 提供了实用判据。
英文摘要
Three-minute ($\sim$5 mHz) oscillations are a prominent signature of wave propagation in the solar chromosphere, but their measured power can vary substantially between full-disc observations and small, high-resolution fields of view. We investigate whether chromospheric magnetic canopy topology, particularly its lateral continuity and areal filling, modulates field-of-view-averaged three-minute power. We analyse H$α$ and Ca II 8542 Å spectral imaging from the Swedish 1-m Solar Telescope, comparing canopy-poor quiet-Sun scenes with canopy-dominated active-region environments, complemented by radiative-MHD Bifrost simulations of canopy-poor and canopy-rich atmospheres. We compute field-of-view-averaged power spectra from fixed-wavelength intensities and bisector-derived velocities in the observations, and from synthetic intensities, velocities, and temperature proxies in the simulations. We also quantify the relation between integrated 3-5 mHz excess power and canopy filling factor, using HMI-based magnetic-field extrapolations for the observations. In both observations and simulations, canopy-poor scenes show clear 3-5 mHz power enhancements, whereas canopy-dominated scenes show strongly reduced measured power. The trend is present in H$α$ and Ca II 8542 Å intensities and is supported by complementary velocity and temperature proxies. Integrated 3-5 mHz excess power decreases with increasing canopy filling factor. We conclude that chromospheric field-of-view-averaged three-minute power is a topology-weighted observable: dense, laterally continuous magnetic canopies can strongly reduce the measured large-scale three-minute signature without requiring the absence of local wave activity. This provides a practical criterion for interpreting chromospheric oscillation power as a proxy for atmospheric wave energy in the Sun and in magnetised cool-star atmospheres.
CommentsAccepted for publication in Astronomy & Astrophysics
