AI 中文总结
本研究通过Bifrost与MURaM-ChE rMHD模型，利用1.5维方法对比Ca I 4227线的Hanle效应，发现两者偏振轮廓差异源于热磁结构不同，MURaM-ChE线心磁化更弱。
AI 中文摘要
对Ca I 4227 Å线的散射偏振进行建模，对于诊断色球层磁场具有重要意义。我们利用真实的太阳大气，通过Hanle效应，研究形成高度和磁场对空间平均合成Stokes轮廓的相对影响。我们采用Bifrost和MURaM-ChE代码对太阳色球层进行的3D辐射磁流体动力学模拟得到的1D垂直柱，求解包含部分频率再分布和Hanle效应的1.5维非局部热力学平衡偏振辐射转移方程。两种模拟得到的强度轮廓在线心处一致，而MURaM-ChE因形成区域更深、温度更高，表现出增强的翼强度；在MURaM-ChE中，偏振信号的形成高度比在Bifrost中更高。在无磁场情况下，Bifrost产生更强的线心偏振，而MURaM-ChE显示增强的翼偏振；包含模拟得到的磁场后，Bifrost中<Q>/<I>的Hanle退偏振更强。因此，对应形成高度处不同的热结构和磁结构产生了显著不同的偏振轮廓，特别是Hanle特征表明，MURaM-ChE中的线心形成区域磁化强度弱于Bifrost中的线心形成区域。
英文摘要
Modeling scattering polarization in the Ca I 4227 Å line is important for diagnosing chromospheric magnetic fields. We investigate the relative influence of formation heights and magnetic fields, through the Hanle effect, on spatially averaged synthetic Stokes profiles using realistic solar atmospheres. We employ 1D vertical columns from 3D radiative magnetohydrodynamic simulations of the solar chromosphere performed with the Bifrost and MURaM-ChE codes, and solve the 1.5D non-local thermodynamic equilibrium polarized radiative transfer equation including partial frequency redistribution and the Hanle effect. The intensity profiles from both simulations agree at line center, while MURaM-ChE exhibits enhanced wing intensity due to deeper, hotter formation regions. The polarization signals form at greater heights in MURaM-ChE than in Bifrost. In the non-magnetic case, Bifrost produces stronger line-core polarization, whereas MURaM-ChE shows enhanced wing polarization. Including the magnetic fields from the simulations results in stronger Hanle depolarization of <Q>/<I> in Bifrost. The distinct thermal and magnetic structures at the corresponding formation heights therefore produce significantly different polarization profiles. In particular, the Hanle signatures suggest that the line-core formation region in MURaM-ChE is less strongly magnetized than that in Bifrost.
