Dormant black holes and neutron stars in stellar binaries

黑洞（BHs）可能是爱因斯坦广义相对论中最奇异的预言：在一个时空区域，引力如此之强，以至于任何东西，甚至光，都无法逃脱。模型预测银河系中存在超过1亿个黑洞，但迄今为止只发现了大约20个。这项提议试图通过使用地面望远镜、盖亚宇宙飞船的数据和新的数据分析方法来增加黑洞的数量，这些方法是通过黑洞对绕其运行的恒星的引力效应来探测黑洞的。加州理工学院的一个研究小组将使用该小组开发的各种观测和理论工具进行调查。在此过程中，研究人员还希望发现一个前所未有的中子星样本——质量较低的黑洞近亲——由类似太阳的恒星环绕。最终目标是对我们银河系的黑洞和中子星数量进行普查，这将最终提高我们对恒星演化、超新星和致密天体形成的物理学的理解。大部分研究将由博士生进行，并将构成该学生论文的中心支柱。该小组还将为本科生实验室开发以轨道动力学为中心的开源材料。PI将继续进行公开演讲，并与加州理工学院的Future ignite项目合作，支持STEM领域代表性不足的少数族裔学生（例如黑人、非裔美国人、美洲原住民和太平洋岛民）。该团队将使用一系列地面和太空设施来发现和描述第一个休眠黑洞（BHs）和中子星（NSs）的统计样本，这些黑洞和中子星位于距离很远的双星中。候选人将从盖亚任务最近发布的第三次数据中选择，该任务为前所未有的350,000个天体测量和光谱双星提供轨道解决方案。该数据集的样本量比以前的所有工作增加了50倍，因此为搜索稀有物体提供了新的机会。该小组将使用地面望远镜对最佳候选者进行光谱跟踪。该计划的主要目标是：(1)获得盖亚样品中所有约100个高概率具有BH或NS成分的双星的光谱和多历元径向速度；(2)在1 ~ 15个太阳质量范围内测量黑洞和黑洞的质量分布，探测或排除质量缺口；(3)双星偏心和双星分离限制了黑洞和黑洞出生踢球的频率和大小；(4)在含有黑洞的双星中检测或排除看不见的三元系的存在。这个项目推进了NSF宇宙大构想窗口的目标。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Black holes (BHs) are perhaps the most bizarre prediction of Einstein's theory of general relativity: regions of spacetime where gravity is so strong that nothing, not even light, can escape. Models predict that more than 100 million BHs exist in the Milky Way, yet only about 20 have been discovered to date. This proposal seeks to increase that number by using telescopes on the ground, data from the Gaia spacecraft, and novel data analysis methods to detect BHs via their gravitation effects on stars that orbit them. A research group at the California Institute of Technology will carry out the investigation using a variety of observational and theoretical tools developed by that group. Along the way, the researchers also expect to discover an unprecedented sample of neutron stars -- close cousins of BHs with lower masses -- orbited by stars like the Sun. The ultimate goal is a census of our Galaxy's BH and neutron star population, which will ultimately improve our understanding of the physics of stellar evolution, supernovae, and compact object formation. A majority of the research will be carried out by a PhD student and will form the central pillar of that student's thesis. The group will also develop open-source material for undergraduate labs centered around orbital dynamics. The PI will continue to give public talks and work with the Future Ignited program at Caltech to support students who are members of under-represented minorities in STEM (for example, Black, African-American, Native American and Pacific Islanders). The team will use a range of ground- and space-based facilities to discover and characterize the first statistical sample of dormant black holes (BHs) and neutron stars (NSs) in binaries with widely separated stellar companions. Candidates will be selected from the recent 3rd data release of the Gaia mission, which provides orbital solutions for an unprecedented 350,000 astrometric and spectroscopic binaries. The dataset represents a factor of 50 increase in sample size over all previous work and thus provides novel opportunities to search for rare objects. The group will use ground-based telescopes to follow-up the best candidates spectroscopically. The main goals of the program are to (1) obtain spectroscopy and multi-epoch radial velocities for all ~100 binaries in the Gaia sample with high probability of having BH or NS components; (2) measure the mass distribution of BHs and NSs from 1 to 15 solar masses, detecting or ruling out the mass gap; (3) constrain the frequency and magnitude of natal kicks for BHs and NSs from binary eccentricities and separations; and (4) detect or rule out the presence of unseen tertiaries within binaries containing BHs. This project advances the goals of the NSF Windows on the Universe Big Idea.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.