Investigation of intergranular bright points from the New Vacuum Solar Telescope  

作　　者：Kai-Fan Ji Jian-Ping Xiong Yong-Yuan Xiang Song Feng Hui Deng Feng Wang Yun-Fei Yang 

机构地区：[1]Faculty of Information Engineering and Automation/Yunnan Key Laboratory of Computer Technology Application,Kunming University of Science and Technology [2]Key Laboratory of Solar Activity, National Astronomical Observatories, Chinese Academy of Sciences [3]Key Laboratory of Modern Astronomy and Astrophysics, Nanjing University, Ministry of Education [4]Yunnan Observatories, Chinese Academy of Sciences

出　　处：《Research in Astronomy and Astrophysics》2016年第5期69-80,共12页天文和天体物理学研究（英文版）

基　　金：the support received from the National Natural Science Foundation of China (Nos. 11573012, 11303011, 11263004, 11163004 and U1231205);the Open Research Program of the Key Laboratory of Solar Activity of the Chinese Academy of Sciences (Nos. KLSA201414 and KLSA201505)

摘　　要：Six high-resolution TiO-band image sequences from the New Vacuum Solar Telescope （NVST） are used to investigate the properties of intergranular bright points （igBPs）. We detect the igBPs using a Laplacian and morphological dilation algorithm （LMD） and automatically track them using a three- dimensional segmentation algorithm, and then investigate the morphologic, photometric and dynamic prop- erties of igBPs in terms of equivalent diameter, intensity contrast, lifetime, horizontal velocity, diffusion index, motion range and motion type. The statistical results confirm previous studies based on G-band or TiO-band igBPs from other telescopes. These results illustrate that TiO data from the NVST are stable and reliable, and are suitable for studying igBPs. In addition, our method is feasible for detecting and track- ing igBPs with TiO data from the NVST. With the aid of vector magnetograms obtained from the Solar Dynamics Observatory/Helioseismic and Magnetic Imager, the properties of igBPs are found to be strongly influenced by their embedded magnetic environments. The areal coverage, size and intensity contrast values of igBPs are generally larger in regions with higher magnetic flux. However, the dynamics of igBPs, includ- ing the horizontal velocity, diffusion index, ratio of motion range and index of motion type are generally larger in the regions with lower magnetic flux. This suggests that the absence of strong magnetic fields in the medium makes it possible for the igBPs to look smaller and weaker, diffuse faster, and move faster and further along a straighter path.Six high-resolution TiO-band image sequences from the New Vacuum Solar Telescope （NVST） are used to investigate the properties of intergranular bright points （igBPs）. We detect the igBPs using a Laplacian and morphological dilation algorithm （LMD） and automatically track them using a three- dimensional segmentation algorithm, and then investigate the morphologic, photometric and dynamic prop- erties of igBPs in terms of equivalent diameter, intensity contrast, lifetime, horizontal velocity, diffusion index, motion range and motion type. The statistical results confirm previous studies based on G-band or TiO-band igBPs from other telescopes. These results illustrate that TiO data from the NVST are stable and reliable, and are suitable for studying igBPs. In addition, our method is feasible for detecting and track- ing igBPs with TiO data from the NVST. With the aid of vector magnetograms obtained from the Solar Dynamics Observatory/Helioseismic and Magnetic Imager, the properties of igBPs are found to be strongly influenced by their embedded magnetic environments. The areal coverage, size and intensity contrast values of igBPs are generally larger in regions with higher magnetic flux. However, the dynamics of igBPs, includ- ing the horizontal velocity, diffusion index, ratio of motion range and index of motion type are generally larger in the regions with lower magnetic flux. This suggests that the absence of strong magnetic fields in the medium makes it possible for the igBPs to look smaller and weaker, diffuse faster, and move faster and further along a straighter path.

关 键 词：techniques： image processing -- Sun： photosphere -- methods： data analysis -- methods：statistical 

分 类 号：P111.41[天文地球—天文学]