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arXiv 2204.04410astro-ph.SR
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近赤道冕洞的热和磁场结构

Thermal and magnetic field structure of near equatorial coronal holes

K. M. Hiremath, Manjunath Hegde

摘要:

我们使用全磁盘,SOHO/EIT 195 $Å$校准的图像来测量近赤道冕洞的面积和平均光子通量的纬向和逐日变化。此外,还估算了冕洞发射的能量及其温度和磁场结构的强度。通过对2001-2008年资料的分析,发现冕洞的平均面积(A)、光子通量(F)、辐射能量(E)和温度(T)的变化与纬度无关。而冕洞磁场结构的推断强度取决于纬度,从赤道附近的低到两极附近的高。估计的物理参数的典型平均值为:$A \sim 3.8(\pm0.5)\times10^{20}~cm^{2}, F \sim 2.3(\pm0.2)\times10^{13}~photons\;cm^{-2}\;sec^{-1}, E \sim 2.32(\pm0.5)\times 10^{3}~ergscm^{-2}sec^{-1} \ and \ T \sim 0.94(\pm0.1)\times10^{6} ~$ K。日冕处冕洞磁场结构的平均强度估计为$\sim$ $0.08 \pm 0.02$高斯。如果冕洞被固定在对流区,人们会认为它们应该有差异地旋转。因此,热成风平衡和冕洞与太阳等离子体的同旋意味着赤道和两极之间的温差。与这一事实相反,近赤道冕洞的热结构的变化是独立的纬度导致的结论是,冕洞必须刚性旋转,很可能是锚定最初低于速跃层确认我们以前的研究(ApJ,763,137,2013)。

英文摘要:

We use full-disk, SOHO/EIT 195 $Å$ calibrated images to measure latitudinal and day to day variations of area and average photon fluxes of the near equatorial coronal holes. In addition, energy emitted by the coronal holes with their temperature and strength of magnetic field structures are estimated. By analyzing data of 2001-2008, we find that variations of average area (A), photon flux (F), radiative energy (E) and temperature (T) of coronal holes are independent of latitude. Whereas inferred strength of magnetic field structure of the coronal holes is dependent on the latitudes and varies from low near the equator to high near both the poles. Typical average values of estimated physical parameters are: $A \sim 3.8(\pm0.5)\times10^{20}~cm^{2}, F \sim 2.3(\pm0.2)\times10^{13}~photons\;cm^{-2}\;sec^{-1}, E \sim 2.32(\pm0.5)\times 10^{3}~ergscm^{-2}sec^{-1} \ and \ T \sim 0.94(\pm0.1)\times10^{6} ~$ K. Average strength of magnetic field structure of coronal hole at the corona is estimated to be $\sim$ $0.08 \pm 0.02$ Gauss. If coronal holes are anchored in the convection zone, one would expect they should rotate differentially. Hence, thermal wind balance and isorotation of coronal holes with the solar plasma implies the temperature difference between the equator and both the poles. Contrary to this fact, variation of thermal structure of near equatorial coronal holes is independent of latitude leading to a conclusion that coronal holes must rotate rigidly that are likely to be anchored initially below the tachocline confirming our previous study (ApJ, 763, 137, 2013).

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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