Title: High resolution reddening map in the direction of the stellar system Terzan 5 Show Chinese title

Title: 高分辨率消光图在恒星系统Terzan 5的方向上

Abstract: We have used optical images acquired with the Hubble Space Telescope to construct the first high-resolution extinction map in the direction of Terzan 5, a peculiar stellar system in the inner bulge of our Galaxy. The map has a spatial resolution of 8" X 8", over a total FoV of 200" X 200". The absorption clouds show a patchy structure on a typical scale of 20" and extinction variations as large as delta E(B-V) = 0.67 mag, especially in the direction of the center of the system. These correspond to an absolute color excess ranging from E(B-V)=2.15 mag, up to 2.82 mag. After the correction for differential reddening, two distinct red giant branches become clearly visible in the color magnitude diagram of Terzan 5 and they well correspond to the two sub-populations with different iron abundances recently discovered in this system. Show Chinese abstract

Abstract: 我们使用哈勃空间望远镜获取的光学图像，构建了指向Terzan 5的第一个高分辨率消光图，Terzan 5是我们银河系内部 bulge 中一个特殊的恒星系统。该图的空间分辨率为8" X 8"，总视场为200" X 200"。吸收云在典型尺度为20"的情况下呈现出斑块状结构，消光变化最大可达delta E(B-V) = 0.67 mag，尤其是在系统中心方向。这些对应于绝对颜色过量从E(B-V)=2.15 mag到2.82 mag。在对差分红化进行校正后，Terzan 5的色-光度图中清晰可见两条不同的红巨星分支，它们很好地对应于最近在这个系统中发现的具有不同铁丰度的两个子种群。