Combining magneto-hydrostatic constraints with Stokes profiles inversions
Combining magneto-hydrostatic constraints with Stokes profiles inversions
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DOI：
10.1051/0004-6361/202039927
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发表时间：
2021-01
影响因子：
6.5
通讯作者：
J. Borrero;A. Pastor Yabar;B. Ruiz Cobo
中科院分区：
文献类型：
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作者：
J. Borrero;A. Pastor Yabar;B. Ruiz Cobo
背景：应用于偏振光辐射传输方程的反演技术能够从谱线中的斯托克斯矢量(即光谱偏振观测)的观测中推断太阳大气中的物理参数(温度T、磁场dB和视线速度vlos)。推论通常在(x，y，τc)域中执行，其中τ折皱到光学深度标度。通常，由于缺乏对气体压力的可靠估计，它们在(x，y，z)体积中的确定是不可能的。目的：我们的目标是开发一种新的能够可靠地推断(x，y，z)域中的物理参数的反演程序。我们以一种自洽的方式将辐射传递方程(Firtez-DZ)的逆解器与磁流体静力平衡的求解器相结合，结果：我们用Hinode航天器上的光谱偏振仪(SP)记录的两个太阳黑子的光谱偏振观测数据来测试新开发的程序的正确行为，并展示了如何在(x，y，z)域推断物理参数，其中太阳黑子的威尔逊凹陷是力平衡的自然结果。特别是，我们的方法比以前基于半经验模型的测定方法有了显著的改进。结论.我们的结果为计算太阳光球层中三维可靠电流j(x，y，z)的可能性打开了大门。进一步的一致性检查将包括与最近提出的实现类似目标的其他方法进行比较。
Context.Inversion techniques applied to the radiative transfer equation for polarized light are capable of inferring the physical parameters in the solar atmosphere (temperatureT, magnetic fieldB, and line-of-sight velocityvlos) from observations of the Stokes vector (i.e., spectropolarimetric observations) in spectral lines. Inferences are usually performed in the (x, y, τc) domain, whereτcrefers to the optical-depth scale. Generally, their determination in the (x, y, z) volume is not possible due to the lack of a reliable estimation of the gas pressure, particularly in regions of the solar surface harboring strong magnetic fields.Aims.We aim to develop a new inversion code capable of reliably inferring the physical parameters in the (x, y, z) domain.Methods.We combine, in a self-consistent way, an inverse solver for the radiative transfer equation (Firtez-DZ) with a solver for the magneto-hydrostatic equilibrium, which derives realistic values of the gas pressure by taking the magnetic pressure and tension into account.Results.We test the correct behavior of the newly developed code with spectropolarimetric observations of two sunspots recorded with the spectropolarimeter (SP) instrument on board the Hinode spacecraft, and we show how the physical parameters are inferred in the (x, y, z) domain, with the Wilson depression of the sunspots arising as a natural consequence of the force balance. In particular, our approach significantly improves upon previous determinations that were based on semiempirical models.Conclusions.Our results open the door for the possibility of calculating reliable electric currents in three dimensions,j(x, y, z), in the solar photosphere. Further consistency checks would include a comparison with other methods that have recently been proposed and which achieve similar goals.