中国空间站望远镜(CSST) 密集星场天体自行研究
Stellar Proper Motion Study of Crowded Stellar Field of CSST
聂嘉潞，曹子皇，刘超，田海俊，田浩， 张鑫，韦成亮，李晓波，班章，赵永恒
作者信息
摘要
对密集星场自行研究是天体测量领域的难题之一，深刻地影响着相关领域的发展。空间观测对于研究密集星场的优势十分明显。CSST 可以提供高精度绝对自行，弥补 HST 在观测覆盖范围以及 Gaia 在暗弱星等方面的不足。银河系核球区作为典型的密集星场天区，具备很强科学价值，但数据处理方面面临很大挑战。以银河系核球区为例，验证了绝对自行处理方法，并对CSST 密集星场的观测策略提出建议。基于 CSST 核球区仿真观测图像，开展数据处理方法的研究和验证。使用两种定心方法并进行比较，定心精度可达近 0.03 ∼ 0.08 pixel。以 10 a 为基线长度，对比了不同观测方法下所得到绝对自行的精度，发现等间隔观测的策略最优。基于此方法，得出结论：对于 18 ∼ 24 mag 的恒星，通过 6 次观测，可以得到好于 0.2 mas/a 的绝对自行精度。最后，估计了不同时间基线和恒星速度下视差对自行的影响。
Abstract
The stellar absolute proper motion of crowded field is an important problem of astrometry. The space-based observation could get high spatially revolved images in the crowded field. The China Space Station Telescope (CSST) can provide high precision absolute proper motion that significantly improve the performance of HST and Gaia in the sky area and deepness of observation. The Galactic bulge, as it is of importance in galactic science and is difficult to process, was selected as a sample of the high-density area to test our method and CSST observation performances. We simulated the CSST observed image and implement our test on it. Two centering methods are conducted, and the precision of centering is about 0.03 to 0.08 pixels depending on the magnitude. The absolute proper motion was measured under different observation strategies in the 10 a baseline. After comparison, we find that equal interval observation is the best choice. We then conclude that six observations can obtain the precision of proper motion is better than 0.2 mas/a between 18 24 mag. Finally, we estimate the effect of parallax in the proper motion estimation under the different time baselines and stellar velocities.关键词
密集星场/空间天文观测/银河系/自行Key words
crowded star field/space astronomical observation/galaxy/proper motion引用本文复制引用
聂嘉潞，曹子皇，刘超，田海俊，田浩， 张鑫，韦成亮，李晓波，班章，赵永恒.中国空间站望远镜(CSST) 密集星场天体自行研究[EB/OL].(2023-12-13)[2026-04-03].https://chinaxiv.org/abs/202312.00178.学科分类
天文学
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