发表机构
University of Colorado; National Institute of Standards and Technology; Université Côte d’Azur; Observatoire de la Côte d’Azur（科罗拉多大学; 美国国家标准与技术研究院; 蔚蓝海岸大学; 蔚蓝海岸天文台）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究通过双星种群合成模型，结合Gaia数据，发现TP-AGB阶段至少10次随机方向的踢（累积均方根速度约0.7 km/s）可解释WD-MS双星观测，但无法满足WD-WD约束。
AI 中文摘要
包含白矮星（WD）的宽距双星为探索主序后（post-MS）与非对称质量损失相关的诞生踢提供了途径。在本工作中，我们开发了一个双星种群合成模型，该模型包含了在恒星演化的热脉冲渐近巨分支（TP-AGB）阶段（此时质量损失预计最为显著）的间歇性质量损失和速度踢。我们将合成的种群与Gaia DR2和DR3数据中的宽距WD-MS和WD-WD双星进行比较，改变TP-AGB踢的数量、强度和方向性。我们发现观测到的间距分布可以约束踢的强度，但仅凭间距分布不足以同时约束踢的数量和维度。因此，我们进一步使用观测到的偏心率分布来约束我们的模型。在质量损失引起恒星速度随机游走的模型中，WD-MS双星的观测偏心率约束最为一致。没有模型与WD-WD偏心率约束相符。我们的结果表明，在TP-AGB阶段至少发生10次随机方向的踢，导致累积的均方根踢速度约为0.7 km/s。这些发现约束了WD诞生踢的性质，将演化宽距双星的轨道分布与恒星演化最后阶段的非对称质量损失联系起来。
英文摘要
Wide binaries containing white dwarfs (WDs) provide a pathway to exploring post-main-sequence (MS) natal kicks associated with asymmetric mass loss. In this work, we develop a binary population synthesis model that involves episodic mass loss and velocity kicks during the thermally-pulsing asymptotic-giant-branch (TP-AGB) phase of stellar evolution, when mass loss is expected to be most significant. We compare our synthesized populations against the Gaia DR2 and DR3 data for wide WD-MS and WD-WD binaries, varying the number, strength, and directionality of TP-AGB kicks. We find that the observed separation distribution can constrain the kick strength, but it alone is insufficient to also constrain the kick number and dimensionality. We therefore additionally constrain our models using the observed eccentricity distributions. Models where mass loss induces a random walk in the star's velocity are most consistent with observed eccentricity constraints for WD-MS binaries. No models are found to agree with the WD-WD eccentricity constraint. Our results suggest that at least 10 randomly directed kicks take place during the TP-AGB phase, leading to a cumulative root-mean-square kick velocity of approximately 0.7 km/s. These findings constrain the nature of WD natal kicks, connecting the orbital distributions of evolved wide binaries to asymmetric mass loss during the final stages of stellar evolution.
CommentsPart 1 of 2, 16 pages, 8 figures. To be submitted to ApJ. Comments welcome!
