AI 中文总结
本研究利用Sunrise III气球观测，通过Ca II和Fe I谱线分析太阳活动区谱斑磁场，发现磁场随高度减弱、磁化区域扩大，为磁场分层演化提供定量证据。
AI 中文摘要
我们利用Sunrise III平流层气球飞行任务的共空间紫外（UV）和红外（IR）光谱偏振观测，研究太阳活动区（AR）谱斑中从上层光球到上层色球的视线（LOS）磁场高度变化。Ca II K和Ca II 8542 Å谱线提供互补的色球诊断，而附近的Fe I谱线采样光球层。通过强度和圆偏振轮廓推断视线磁场，对Ca II谱线采用弱场近似，对Fe I谱线采用重心法。光球Fe I谱线揭示了约1千高斯（kG）的强且精细结构的磁场；相比之下，色球Ca II诊断得到的磁场系统地更弱，通常在约100-400高斯（G）范围内，空间分布更弥散。由形成于色球更高处的Ca II K线推断的磁场图，比采样更低高度的Ca II 8542 Å线得到的磁场图更平滑且延展范围更大。我们发现，从光球到色球，磁化区域增加了约2倍。这些结果提供了直接定量证据，表明活动区谱斑中的磁场随高度减弱并扩展，从紧凑的千高斯级光球聚集区演变为上层色球中更弱、空间分布更延展的结构。
英文摘要
We investigate the height variation of the line-of-sight (LOS) magnetic field in solar active-region (AR) plage from the upper photosphere to the upper chromosphere using co-spatial ultraviolet (UV) and infrared (IR) spectropolarimetric observations from the Sunrise III stratospheric balloon flight. The Ca II K and Ca II 8542 Å lines provide complementary chromospheric diagnostics, while nearby Fe I lines sample photospheric layers. The LOS magnetic field is inferred from the intensity and circular polarization profiles, applying the weak field approximation for the Ca II lines and the center-of-gravity method for the Fe I lines. The photospheric Fe I lines reveal strong, finely structured magnetic fields of the order of a kG. In contrast, the chromospheric Ca II diagnostics yield systematically weaker fields, typically in the $\sim$ 100-400 G range, with a more diffuse spatial distribution. Magnetic field maps inferred from the Ca II K line, formed higher in the chromosphere, are smoother and more extended than those derived from the Ca II 8542 Å line, which samples lower heights. We find that the magnetized area increases by a factor of $\sim$ 2 from the photosphere to the chromosphere. These results provide direct quantitative evidence that magnetic fields in AR plage weaken and expand with height, evolving from compact kG photospheric concentrations into weaker and more spatially extended structures in the upper chromosphere.
Comments9 pages, 4 figures, 4 appendices. Accepted for publication in The Astrophysical Journal Letters; Sunrise III focus issue
Journal refThe Astrophysical Journal Letters, 1007, L3 (2026)
