标题： 星群中较少的伴星：来自盖亚RVS的球状星团低近距离双星比例 显示英文标题

标题： Fewer Companions in the Crowd: The Low Close Binary Fraction in Globular Clusters from Gaia RVS

摘要： 在如球状星团（GCs）这样的密集环境中，动力学相互作用可以破坏或使密近双星系统变硬，尽管如此，与场双星分数的详细比较仍然有限。 在这里，我们使用盖亚径向速度光谱仪（RVS）数据，对一个精心选择的场星样本和10个GCs中的密近双星分数进行了分析，这是迄今为止使用多历元光谱学分析的GCs最大的样本之一。 通过评估源的径向速度（RV）的峰峰值变化，我们通过一种将分布拟合为两个高斯分布乘积的方法来估计密近双星分数。 通过对集群成员和场星应用相同的RV变化方法，我们确保了两种环境之间的同质且全面的比较。 尽管场星和GC样本中的恒星参数相匹配，但我们的研究结果证实，GCs的密近双星分数明显低于场星。 有趣的是，我们没有检测到双星分数与星团金属量之间的明显趋势；富金属和贫金属GCs都表现出均匀的双星贫乏（在误差范围内）。 我们讨论了可能的解释，包括密集环境中的动力学硬化以及共同包层演化的效应，这可能导致伴星吸积或合并事件。 显示英文摘要

摘要： In dense environments like globular clusters (GCs), dynamical interactions can disrupt or harden close binaries, nonetheless, detailed comparisons with field binary fractions remain limited. Here, we present an analysis of the close binary fraction in a carefully selected sample of field stars and 10 GCs using Gaia Radial Velocity Spectrometer (RVS) data, which is among the largest samples of GCs analysed using multi-epoch spectroscopy to date. By assessing the peak-to-peak variations of the sources' radial velocity (RV), we estimate the close binary fractions through a method that fits the distribution as the product of two Gaussian distributions. By applying the same RV-variability method to both cluster members and field stars, we ensure a homogeneous and inclusive comparison between the two environments. Despite matching stellar parameters between the field and GC samples, our findings confirm that GCs possess a significantly lower close binary fraction than field stars. Interestingly, we do not detect any clear trend of binary fraction with cluster metallicity; metal-rich and metal-poor GCs are uniformly binary-poor (within uncertainties). We discuss possible interpretations, including dynamical hardening in dense environments and the effects of common envelope evolution, which may lead to companion accretion or merger events.