论文标题
将磁静电限制与Stokes曲线倒置相结合。 iii。电流推断的不确定性
Combining magneto-hydrostatic constraints with Stokes profiles inversions. III. Uncertainty in the inference of electric currents
论文作者
论文摘要
电流在太阳大气中血浆的能量平衡中起着重要作用。它们还表示非电位磁场和磁重新连接。不幸的是，传统上，电流的直接测量充满了不准确性。我们研究在不同情况下如何准确推断电流。我们对辐射转移方程式进行了越来越复杂的反转，用于用于从辐射三维磁水动力学（MHD）模拟中合成的sTokes剖面的极化光。反转产生磁场向量，$ {\ bf b} $，通过应用安培定律，从中获得电流密度$ {\ bf j} $。我们发现，电流密度的检索仅受光子噪声或光谱分辨率的影响。然而，随着斯托克斯倒置变得越来越详细，检索稳步改善。 In the least complex case (a Milne-Eddington-like inversion applied to a single spectral region), it is possible to determine the individual components of the electric current density ($j_{\rm x}$, $j_{\rm y}$, $j_{\rm z}$) with an accuracy of $σ=0.90-1.00$ dex, whereas the modulus （$ \ | {\ bf j} \ | $）只能用$σ= 0.75 $ dex确定。在最复杂的情况下（具有多个光谱区域，大量节点，Tikhonov垂直正则化和磁液静态平衡），这些数字提高到$σ= 0.70-0.75 $ DEX，用于单个组件，$σ= 0.5 = 0.5 $ dex for Modulus。此外，在磁场高于300高斯的区域中，可以以$σ= 0.3 $ dex的精度来推断$ \ | {\ bf j} \ | $。通常，电流密度的$ x $和$ y $组件比$ z $组件的检索稍好。
Electric currents play an important role in the energy balance of the plasma in the solar atmosphere. They are also indicative of non-potential magnetic fields and magnetic reconnection. Unfortunately, the direct measuring of electric currents has traditionally been riddled with inaccuracies. We study how accurately we can infer electric currents under different scenarios. We carry out increasingly complex inversions of the radiative transfer equation for polarized light applied to Stokes profiles synthesized from radiative three-dimensional magnetohydrodynamic (MHD) simulations. The inversion yields the magnetic field vector, ${\bf B}$, from which the electric current density, ${\bf j}$, is derived by applying Ampere's law. We find that the retrieval of the electric current density is only slightly affected by photon noise or spectral resolution. However, the retrieval steadily improves as the Stokes inversion becomes increasingly elaborated. In the least complex case (a Milne-Eddington-like inversion applied to a single spectral region), it is possible to determine the individual components of the electric current density ($j_{\rm x}$, $j_{\rm y}$, $j_{\rm z}$) with an accuracy of $σ=0.90-1.00$ dex, whereas the modulus ($\|{\bf j}\|$) can only be determined with $σ=0.75$ dex. In the most complicated case (with multiple spectral regions, a large number of nodes, Tikhonov vertical regularization, and magnetohydrostatic equilibrium), these numbers improve to $σ=0.70-0.75$ dex for the individual components and $σ=0.5$ dex for the modulus. Moreover, in regions where the magnetic field is above 300 gauss, $\|{\bf j}\|$ can be inferred with an accuracy of $σ=0.3$ dex. In general, the $x$ and $y$ components of the electric current density are retrieved slightly better than the $z$ component.
