Close Binary Companions to APOGEE DR16 Stars: 20,000 Binary-star Systems Across the Color–Magnitude Diagram
Close Binary Companions to APOGEE DR16 Stars: 20,000 Binary-star Systems Across the Color–Magnitude Diagram
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DOI：
10.3847/1538-4357/ab8acc
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发表时间：
2020-01
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通讯作者：
A. Price-Whelan;D. Hogg;H. Rix;R. Beaton;H. Lewis;D. Nidever;Andr'es Almeida;C. Badenes
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作者：
A. Price-Whelan;D. Hogg;H. Rix;R. Beaton;H. Lewis;D. Nidever;Andr'es Almeida;C. Badenes
当代天体物理学中的许多问题从理解黑洞的形成到解开星系的化学演化都依赖于对双星的了解。这反过来又取决于在不同的化学和动力学环境中发现和描述大量不同类型恒星的双星伴星。目前的恒星光谱巡天观测到数十万至数百万颗恒星，（通常）只有很少的观测时期，这允许发现双星，但使轨道特征具有挑战性。我们使用一个自定义的蒙特卡罗采样器（The Monte Carlo sampler），通过径向速度，在稀疏，嘈杂和采样差的多历元数据的制度，执行发现和表征的二进制系统。我们使用它来生成开普勒参数的后验样本，用于APOGEE Data Release 16中发布的232，495个源。我们的最终目录包含19，635个高置信度的近二进制（P <0.05年，0.05年）系统，这些系统显示了二进制出现率和颜色-星等图中位置之间的有趣关系。我们在高质量（黑洞候选者），低质量（亚恒星候选者）和非常接近的分离（质量转移候选者）中发现了显着的微弱同伴。我们还使用后验抽样（玩具）层次推理来测量长周期双星偏心率分布。我们发布了232，495颗恒星的整个母样本的完整后验样本集。这组采样不涉及启发式的“发现”阈值，因此可以用于无数的统计目的，包括关于双星种群和亚阈值搜索的分层推断。
Many problems in contemporary astrophysics—from understanding the formation of black holes to untangling the chemical evolution of galaxies—rely on knowledge about binary stars. This, in turn, depends on the discovery and characterization of binary companions for large numbers of different kinds of stars in different chemical and dynamical environments. Current stellar spectroscopic surveys observe hundreds of thousands to millions of stars with (typically) few observational epochs, which allows for binary discovery but makes orbital characterization challenging. We use a custom Monte Carlo sampler (The Joker) to perform discovery and characterization of binary systems through radial velocities, in the regime of sparse, noisy, and poorly sampled multi-epoch data. We use it to generate posterior samplings in Keplerian parameters for 232,495 sources released in APOGEE Data Release 16. Our final catalog contains 19,635 high-confidence close-binary (P ≲ few years, a ≲ few ) systems that show interesting relationships between binary occurrence rate and location in the color–magnitude diagram. We find notable faint companions at high masses (black hole candidates), at low masses (substellar candidates), and at very close separations (mass-transfer candidates). We also use the posterior samplings in a (toy) hierarchical inference to measure the long-period binary-star eccentricity distribution. We release the full set of posterior samplings for the entire parent sample of 232,495 stars. This set of samplings involves no heuristic “discovery” threshold and therefore can be used for myriad statistical purposes, including hierarchical inferences about binary-star populations and subthreshold searches.