AI 中文总结
该研究通过三维磁流体动力学模拟结合pyCELP框架，分析了宁静太阳和活动区两种等离子体状态下扭转阿尔文波的观测特性，指出活动区中无扭转驱动器时也会出现易被误判的红蓝多普勒不对称性。
AI 中文摘要
扭转阿尔文波是通过太阳大气传输能量的一种有前景的机制，对日冕加热和太阳风加速具有重要意义。最近，通过Daniel K. Inouye太阳望远镜观测到了扭转阿尔文波的特征。我们旨在研究视线积分和等离子体条件对扭转模式可观测特性的影响。在此，我们展示了多个日冕波导的三维磁流体动力学模拟，这些模拟由横向扭结和扭转波驱动器的组合驱动，考虑了代表活动区（AR）和宁静太阳（QS）条件的两种等离子体状态。使用pyCELP正演建模框架生成Fe XIII 1074.7 nm日冕发射线的合成可观测物，以实现与光谱观测的直接比较。在宁静太阳状态下，红蓝多普勒不对称性与驱动的扭转波相关，尽管它们的观测振幅因视线积分而大幅降低。相比之下，活动区状态即使在没有施加扭转驱动器的情况下也表现出红蓝多普勒不对称性，这可能被误判为m=0扭转阿尔文模式。在活动区装置中，红蓝多普勒不对称性源于强相位混合，在波导之间产生剪切流和局域涡度，而波导之间的发射最强。两种状态之间的差异由峰值发射的位置决定，而峰值发射的位置由密度不均匀性的程度决定。我们的结果支持在宁静太阳（弱不均匀环境）中识别扭转阿尔文波特征，但在解释活动区等强不均匀环境中的光谱观测时应谨慎。
英文摘要
Torsional Alfvén waves are a promising mechanism for transporting energy through the solar atmosphere, with implications for coronal heating and solar wind acceleration. Recently, signatures of torsional Alfvén waves have been observed with the Daniel K. Inouye Solar Telescope. We aim to investigate the effects of line of sight integration and plasma conditions on the observable properties of the torsional mode. Here we present three-dimensional magnetohydrodynamic simulations of multiple coronal waveguides, driven by a combination of transverse kink and torsional wave drivers, considering two plasma regimes representative of active region (AR) and quiet Sun (QS) conditions. Synthetic observables of the Fe~\textsc{xiii}~1074.7~nm coronal emission line are produced using the pyCELP forward-modelling framework to enable direct comparison with spectroscopic observations. In the QS regime, red-blue Doppler asymmetries are associated with the driven torsional waves, though their observed amplitudes are substantially reduced by line-of-sight integration. In contrast, the AR regime exhibits red-blue Doppler asymmetries even in the absence of an imposed torsional driver, which may be misidentified as the $m=0$ torsional Alfvén mode. In the AR setup, the red-blue Doppler asymmetries arise from strong phase mixing, generating shear flows and localised vorticity between waveguides where emission is strongest. The differences between the two regimes are governed by the location of peak emission, which is determined by the degree of density inhomogeneity. Our results support the identification of torsional Alfvén wave signatures in the quiet Sun (a weakly inhomogeneous environment), but caution should be exercised when interpreting spectroscopic observations in strongly inhomogeneous environments such as active regions.
Comments17 pages, 11 Figures. Accepted for publication in ApJ
