冕洞的磁场演化和温度变化
Magnetic Evolution and Temperature Variation in a Coronal Hole
摘要：
利用2005年10月10日至14日的大熊太阳天文台（BBSO）深磁图和{ \it SOHO}/EIT图像，研究了冕洞区的磁通量演化和温度变化。为了比较，我们还研究了太阳附近的安静区域。在观测期间，冕洞从成熟阶段演变到消失。我们得到以下结果：（1）10月10日冕洞发育良好时，约有60%的磁通量为正。EUV亮度为420计数像素$^{-1}$，根据EIT 195和171毫米图像的线比估计的日冕温度为1.07 MK。(2)10月14日，当冕洞几乎消失时，51%的磁通量为正，极紫外辐射率为530计数像素$^{-1}$，温度为1. 10 MK。(3)在邻近的安静区域，正通量的分数在0.49和0.47之间变化。EUV亮度显示出不规则的变化，平均值为870计数像素$^{-1}$。在五天的观测期间，温度几乎恒定在1.11 MK。我们的结果表明，在冕洞较小的不平衡的磁通量在相反的极性导致更强的EUV亮度和更高的日冕温度。
英文摘要：
We have explored the magnetic flux evolution and temperature variation in a coronal-hole region, using Big Bear Solar Observatory (BBSO) deep magnetograms and {\it SOHO}/EIT images observed from 2005 October 10 to 14. For comparison, we also investigated a neighboring quiet region of the Sun. The coronal hole evolved from its mature stage to its disappearance during the observing period. We have obtained the following results: (1) When the coronal hole was well developed on October 10, about 60 % of the magnetic flux was positive. The EUV brightness was 420 counts pixel$^{-1}$, and the coronal temperature, estimated from the line ratio of the EIT 195 Å and 171 Å images, was 1.07 MK. (2) On October 14, when the coronal hole had almost disappeared, 51 % of the magnetic flux was positive, the EUV radiance was 530 counts pixel$^{-1}$, and the temperature was 1.10 MK. (3) In the neighboring quiet region, the fraction of positive flux varied between 0.49 and 0.47. The EUV brightness displayed an irregular variation, with a mean value of 870 counts pixel$^{-1}$. The temperature was almost constant at 1.11 MK during the five-day observation. Our results demonstrate that in a coronal hole less imbalance of the magnetic flux in opposite polarities leads to stronger EUV brightness and higher coronal temperatures.
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。
