论文标题
通过紧密相遇来限制小行星的内部
Constraining the Interiors of Asteroids Through Close Encounters
论文作者
论文摘要
对小行星的内部密度分布的了解可以揭示其组成并限制其进化史。但是，大多数小行星观察技术对内部特性不敏感。我们通过在近距离接触期间监视角速度的变化来研究内部约束。我们得出了刚性小行星的方向和角速度的运动方程，以使其在密切的地球相遇中为代表性小行星生成合成角速度数据。我们开发了工具包的AIME（来自相遇者的小行星内部映射），从这些数据中重建小行星密度分布，并对这些合成数据进行注射 - 回程测试，以评估AIME的准确性和精度。我们还对小行星参数（例如，小行星形状和轨道元素），观测设置（例如测量精度和节奏）以及所使用的映射模型进行了灵敏度分析。我们发现，在旋转周期估计值（<〜0.27秒）中对于每个节奏都是必需的，并且在某些模型下，低凝聚人（<〜18地球半径）对于解决局部密度的0.1％的不一定确定性是必不可少的。
Knowledge of the interior density distribution of an asteroid can reveal its composition and constrain its evolutionary history. However, most asteroid observational techniques are not sensitive to interior properties. We investigate the interior constraints accessible through monitoring variations in angular velocity during a close encounter. We derive the equations of motion for a rigid asteroid's orientation and angular velocity to arbitrary order and use them to generate synthetic angular velocity data for a representative asteroid on a close Earth encounter. We develop a toolkit AIME (Asteroid Interior Mapping from Encounters) which reconstructs asteroid density distribution from these data, and we perform injection-retrieval tests on these synthetic data to assess AIME's accuracy and precision. We also perform a sensitivity analysis to asteroid parameters (e.g., asteroid shape and orbital elements), observational set-up (e.g., measurement precision and cadence), and the mapping models used. We find that high precision in rotational period estimates (<~0.27 seconds) are necessary for each cadence, and that low perigees (<~18 Earth radii) are necessary to resolve large-scale density non-uniformities to uncertainties ~0.1% of the local density under some models.
