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arXiv 0806.1326astro-ph
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光球宁静太阳区太阳磁场的强度分布

Strength distribution of solar magnetic fields in photospheric quiet Sun regions

J. C. Ramirez Velez, A. Lopez Ariste, M. Semel

摘要:

太阳光球在其最安静区域的磁拓扑结构被隐藏起来,因为难以将通过分辨元件的磁通量与未分辨结构的场强分开。观察与超精细结构强耦合的谱线,例如在553.7 nm处观察到的MnI线,可以实现这种区分。主要目的是通过对553.7 nm MnI谱线的反演,分析太阳光球网和网内的场强分布。本文提出了一种基于主成分分析的磁场反演方法。对程序进行了统计检验,当场强低于某一阈值时,程序必须从观测线Stokes V剖面的核心处的小振幅谱特征中提取信息,该阈值与原子能级精细结构中Paschen-Back效应的下限相一致。使用圆极化(V)和强度(I)对观测到的分布进行反演,结果表明存在磁场强度在0至2 kG范围内,主要为弱强度值。平均强度场值为1130和435高斯的混合区域被发现分别与网络和intrenetwork。在553 nm的MnI线探测的场强分布在安静的太阳,并显示出优势的弱,hectoGauss领域的intranetwork,和强,kiloGauss领域的网络。它还表明,在我们目前的空间分辨率下,网络和内部网络都可以被理解为场分布,我们暗示了场分布的平均性质。

英文摘要:

The magnetic topology of the solar photosphere in its quietest regions is hidden by the difficulties to disentangle magnetic flux through the resolution element from the field strength of unresolved structures. The observation of spectral lines with strong coupling with hyperfine structure, like the observed MnI line at 553.7 nm, allows such differentiation. The main aim is to analyse the distribution of field strengths in the network and intranetwork of the solar photosphere through inversion of the MnI line at 553.7 nm. An inversion code for the magnetic field using the Principal Component Analysis (PCA) has been developed. Statistical tests are run on the code to validate it. The code has to draw information from the small-amplitude spectral feature oppearing in the core of the Stokes V profile of the observed line for field strengths below a certain threshold, coinciding with lower limit of the Paschen-Back effect in the fine structure of the involved atomic levels. The inversion of the observed profiles, using the circular polarization (V) and the intensity (I), shows the presence of magnetic fields strengths in a range from 0 to 2 kG, with predominant weak strength values. Mixed regions with mean strength field values of 1130 and 435 Gauss are found associated with the network and intranetwork respectively. The MnI line at 553 nm probes the field strength distribution in the quiet sun and shows the predominance of weak, hectoGauss fields in the intranetwork, and strong, kiloGauss fields in the network. It also shows that both network and intranetwork are to be understood at our present spatial resolutions as field distributions of which we hint the mean properties.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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