利用双星相对天体测量法寻找宜居系外行星：基于微角秒天体测量检索算法（MARA）的行星探测与表征
Finding Habitable Exoplanets with Binary Relative Astrometry: Planet Detection and Characterization with the Microarcsecond Astrometric Retrieval Algorithm (MARA)
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中文总结 AI 辅助
本研究提出专为双星相对天体测量数据设计的MARA算法，通过模拟测试表明其可探测半人马座α星A宜居带内质量低至0.5个地球质量的岩质行星，结果与理论预测一致，为相关任务的人口统计学研究提供关键依据。
中文摘要 AI 辅助
双星相对天体测量法是一种利用微角秒级别的一维相对天体测量技术，搜寻近距双星宜居带内岩质行星的方法。这种前所未有的精度将使定制设计的空间望远镜能够直接测量这类行星的出现率。此类任务的成功取决于我们从极端精度的双星相对天体测量数据的独特格式中恢复并表征行星的能力。我们提出了专为这类数据设计的微角秒天体测量检索算法（Microarcsecond Astrometric Retrieval Algorithm，MARA）。我们描述了MARA管道的设计与格式，并以SHERA SMEx任务概念为例，通过对模拟数据开展的一系列验证测试，展示了其精度与性能。我们的注入/恢复测试表明，利用这类数据，MARA能够探测并表征半人马座α星A（alpha Cen A）宜居带内的岩质行星，对于1年轨道的共面行星，其质量下限约为1个地球质量（M⊕）。针对同一示例任务，扩展至一系列输入行星质量与轨道周期后，我们发现这些注入/恢复测试的结果与双星相对天体测量灵敏度的解析预测总体一致。我们利用MARA绘制了预期探测完备度随行星质量与轨道周期变化的关系图，在本案例中，半人马座α星A的3年轨道行星，其质量下限可达约0.5 M⊕。这些探测深度计算将是双星相对天体测量任务最终数据人口统计学计算的关键组成部分。
英文摘要
Binary relative astrometry is a technique to search for rocky planets in the habitable zone of nearby binary stars using 1D relative astrometry at the microarcsecond level. This unprecedented precision would allow a custom-designed space telescope to directly measure the occurrence rate of these planets. The success of such a mission depends on our ability to recover and characterize planets from the unique format of extreme precision binary relative astrometry data. We present MARA, the Microarcsecond Astrometric Retrieval Algorithm, specifically designed for these data. We describe the design and format of the MARA pipeline, and demonstrate its accuracy and performance with a series of validation tests on simulated data, using the SHERA SMEx mission concept as an example. Our injection/recovery tests show that with these data, MARA is able to detect and characterize rocky planets in the habitable zone of alpha Cen A, down to a coplanar mass of about 1 Earth mass in 1 year orbits. Expanding to a range of input planet masses and periods for the same example mission, we find that the results from these injection/recovery tests generally agree with the analytic predictions of binary relative astrometry sensitivity. We use MARA to map out the expected completeness as a function of planet mass and period, which in this case reaches down to about 0.5 M Earth masses at 3 year orbits around alpha Cen A. These depth-of-search calculations will be a vital ingredient in demographics calculations from the final data from a binary relative astrometry mission.
