paired: A Statistical Framework for Determining Stellar Binarity with Gaia RVs. I. Planet Hosting Binaries

The effect of stellar multiplicity on the formation and evolution of planetary systems is complex. At a demographic level, campaigns with both high-resolution imaging and radial velocity observations indicate that planet formation is strongly disrupted by close binaries, while being relatively unaffected by wide companions. However, the magnitude and distance-limited nature of those tools mean that large ranges of mass ratios and separations remain largely unexplored. The Early Data Release 3 (EDR3) from the Gaia Mission includes radial velocity measurements of over 6.5 million targets, which we employ to explore the effect of binary companions within a statistical framework called paired. These companions present as a source of excess radial velocity noise in the Gaia catalog, when compared to the typical noise for stars of similar spectral type and magnitude. Within this framework, we examine the evidence for stellar multiplicity among the stars surveyed by NASA's Kepler and TESS missions. We use radial velocity errors published in Gaia EDR3 to estimate the probability of an unresolved stellar companion for a large subset of the Kepler and TESS Input Catalog stars, where possible benchmarking our inferred radial velocity semi-amplitudes against the those from ground-based radial velocity surveys. We determine that we are typically sensitive out to several AU and mass ratios >0.1, dependent upon the stellar magnitude. We aim for paired to be a useful community tool for the exploration of the effects of binarity on planets at a population level, and for efficient identification of false-positive transit candidates.恒星多重性对行星系统形成与演化的影响机制极为复杂。从种群统计层面来看，结合高分辨率成像与视向速度（radial velocity）观测的巡天项目表明，密近双星会强烈干扰行星形成过程，而宽距伴星则对其影响相对有限。然而这类观测工具受星等与距离的双重限制，使得大质量比、宽分离度的双星系统仍有大量参数空间尚未被探索。盖亚任务（Gaia Mission）的早期数据发布3版（EDR3）包含超过650万个观测目标的视向速度测量数据，我们借助该数据集，在名为paired的统计框架下探究双星伴星的影响。相较于同类光谱型与星等的恒星的典型噪声水平，这些伴星会在盖亚星表中表现为额外视向速度噪声的来源。在此统计框架下，我们针对美国国家航空航天局（NASA）开普勒（Kepler）与凌日系外行星巡天卫星（TESS）任务所观测的恒星，检验其存在恒星多重性的证据。我们利用盖亚EDR3中发布的视向速度误差，对开普勒与TESS输入星表中的大量恒星样本估算其存在未解析恒星伴星的概率；在可行范围内，我们将推导得到的视向速度半振幅与地面视向速度巡天的结果进行基准比对。我们的分析表明，该方法通常可探测到数天文单位（AU）范围内、质量比大于0.1的伴星，探测灵敏度受恒星星等影响。我们期望paired能够成为一款实用的社区工具，既可用于从种群层面探究双星性对行星系统的影响，也可高效识别凌星信号的假阳性候选体。