Close substellar-mass companions in stellar wide binaries: Discovery and characterization with APOGEE and Gaia DR2
Close substellar-mass companions in stellar wide binaries: Discovery and characterization with APOGEE and Gaia DR2
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恒星宽双星中的紧密亚恒星质量伴星：利用 APOGEE 和 Gaia DR2 进行发现和表征
DOI：
10.1093/mnras/stab2349
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发表时间：
2021
影响因子：
4.8
通讯作者：
Bizyaev, Dmitry
中科院分区：
文献类型：
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作者：
Lewis, Hannah M;Anguiano, Borja;Majewski, Steven R;Nidever, David L;Badenes, Carles;De Lee, Nathan;Hasselquist, Sten;Daher, Christine Mazzola;Stassun, Keivan G;Bizyaev, Dmitry
我们提出了一个搜索密切的，未解决的同伴在一个子集的spatially resolvedGaiawide二进制包含主序星在200 pc的太阳，利用APOGEE-GaiaWide二进制目录。一个包含37个宽联星的目录是通过选择具有几乎相同的Gaia位置、视差和自行的恒星对，然后使用远地点径向速度确认候选者是引力束缚对而创建的。我们确定密切，未解决的恒星和亚恒星的候选同伴在这些多个系统中使用（1）银河系主序星和（2）观测到的周期性径向速度变化的APOGEE测量由于一个密切的亚恒星质量的同伴的影响。研究的宽双星对揭示了四个不同宽双星中的四个恒星质量的近伴星，以及两个宽双星中的四个亚恒星质量的近伴星候选者。因此，后者是四重系统，其中一个亚恒星质量的伴星在S型轨道上绕着每个宽双星组件运行。从表面上看，这些候选系统代表了一个数量级的增强超过预期的发生率的102%的恒星有亚恒星的同伴>2兆在100-d轨道内，我们讨论了这一结果的影响和可能的解释。最后，我们比较了宽双星的组成部分和候选高阶系统的组成部分之间的化学差异，并发现由于宽双星的近伴星的存在，任何化学影响或相关性是不可辨别的。
We present a search for close, unresolved companions in a subset of spatially resolvedGaiawide binaries containing main-sequence stars within 200 pc of the Sun, utilizing the APOGEE–GaiaWide Binary Catalog. A catalogue of 37 wide binaries was created by selecting pairs of stars with nearly identicalGaiapositions, parallaxes, and proper motions, and then confirming candidates to be gravitationally bound pairs using APOGEE radial velocities. We identify close, unresolved stellar and substellar candidate companions in these multiple systems using (1) theGaiabinary main sequence and (2) observed periodic radial velocity variations in APOGEE measurements due to the influence of a close substellar-mass companion. The studied wide binary pairs reveal a total of four stellar-mass close companions in four different wide binaries, and four substellar-mass close companion candidates in two wide binaries. The latter are therefore quadruple systems, with one substellar-mass companion orbiting each wide binary component in an S-type orbit. Taken at face value, these candidate systems represent an enhancement of an order of magnitude over the expected occurrence rate of ∼2 per cent of stars having substellar companions >2 MJupwithin ∼100-d orbits; we discuss implications and possible explanations for this result. Finally, we compare chemical differences between the components of the wide binaries and the components of the candidate higher-order systems and find that any chemical influence or correlation due to the presence of close companions to wide binary stars is not discernible.