标题： 盖亚天体测量轨道目录的生成模型：双星、巨行星和致密天体伴星的选择函数 显示英文标题

标题： A generative model for Gaia astrometric orbit catalogs: selection functions for binary stars, giant planets, and compact object companions

摘要： 基于盖亚DR3的天文学测量产生了一个包含 $\sim$170,000 个开普勒轨道解的样本，未来几年预计会有更多数据。 这些数据具有巨大的潜力来限制太阳系附近双星、巨行星和致密天体群体的数量。 但为了利用已发布的轨道目录进行统计推断，有必要了解它们的选择函数：一个具有特定属性的双星进入目录的概率是多少？ 我们展示了Gaia DR3天文学双星目录的选择函数可以通过盖亚扫描定律向前建模，包括单个一维天文学测量、一系列天文学模型的拟合以及后处理中的质量裁剪。 我们在一个合成银河系模型中填充了双星，并生成了一个天文学轨道的模拟目录。 该模拟目录与DR3天文学双星样本非常相似，表明我们的选择函数是对现实的一种合理近似。 我们的拟合也产生了类似DR3中发现的虚假天文学轨道样本；这些主要是由于在部分解析的宽双星中，扫描角度依赖性的天文学偏倚造成的。 我们显示，盖亚对天文学双星的敏感度在高离心率时迅速下降，但在高倾角时仅弱相关。 我们预测DR4将产生 $\sim 1$百万个天文学轨道，主要针对明亮（$G \lesssim 15$）且周期长（$P_{\rm orb} \gtrsim 1000$ 天）的系统。 我们提供了代码以模拟和拟合任何数据发布版本的盖亚历元天文学，并确定任何假设的双星是否将获得目录化的轨道解。 显示英文摘要

摘要： Astrometry from Gaia DR3 has produced a sample of $\sim$170,000 Keplerian orbital solutions, with many more anticipated in the next few years. These data have enormous potential to constrain the population of binary stars, giant planets, and compact objects in the Solar neighborhood. But in order to use the published orbit catalogs for statistical inference, it is necessary to understand their selection function: what is the probability that a binary with a given set of properties ends up in a catalog? We show that such a selection function for the Gaia DR3 astrometric binary catalog can be forward-modeled from the Gaia scanning law, including individual 1D astrometric measurements, the fitting of a cascade of astrometric models, and quality cuts applied in post-processing. We populate a synthetic Milky Way model with binary stars and generate a mock catalog of astrometric orbits. The mock catalog is quite similar to the DR3 astrometric binary sample, suggesting that our selection function is a sensible approximation of reality. Our fitting also produces a sample of spurious astrometric orbits similar to those found in DR3; these are mainly the result of scan angle-dependent astrometric biases in marginally resolved wide binaries. We show that Gaia's sensitivity to astrometric binaries falls off rapidly at high eccentricities, but only weakly at high inclinations. We predict that DR4 will yield $\sim 1$ million astrometric orbits, mostly for bright ($G \lesssim 15$) systems with long periods ($P_{\rm orb} \gtrsim 1000$ d). We provide code to simulate and fit realistic Gaia epoch astrometry for any data release and determine whether any hypothetical binary would receive a cataloged orbital solution.