论文标题
NGC 1261的运动学视图：结构参数，内部分散，绝对适当运动和蓝色Straggler星星
A kinematic view of NGC 1261: structural parameters, internal dispersion, absolute proper motion and Blue Straggler Stars
论文作者
论文摘要
我们构建了银河球状群集NGC 1261中心区域的Hubble空间望远镜（HST）星星光度分组。我们通过多上述HST数据计算了高精度的适当动作，并在最内向区域的天空平面中得出了群集速度分散曲线，发现该系统是各向同性的。与外部区域光谱收集的视线信息的结合为我们提供了沿整个径向扩展的群集速度分散曲线。我们还使用一些背景星系作为参考，测量了NGC 1261的绝对正确运动。蓝色Straggler恒星种群的径向分布表明，该簇处于动力学进化的低/中间相。
We constructed a Hubble Space Telescope (HST) astro-photometric catalog of the central region of the Galactic globular cluster NGC 1261. This catalog, complemented with Gaia DR2 data sampling the external regions, has been used to estimate the structural parameters of the system (i.e., core, half-mass, tidal radii and concentration) from its resolved star density profile. We computed high-precision proper motions thanks to multi-epoch HST data and derived the cluster velocity dispersion profile in the plane of the sky for the innermost region, finding that the system is isotropic. The combination with line-of-sight information collected from spectroscopy in the external regions provided us with the cluster velocity dispersion profile along the entire radial extension. We also measured the absolute proper motion of NGC 1261 using a few background galaxies as a reference. The radial distribution of the Blue Straggler Star population shows that the cluster is in a low/intermediate phase of dynamical evolution.
