We present results from the B-type binaries characterization (BBC) programme, a multi-epoch spectroscopic study of 88 early B-type binary candidates in the 30 Doradus region of the Large Magellanic Cloud (LMC). From radial-velocity analysis of 29 observational epochs, we confirm the binary status of 64 of our targets, comprising 50 SB1 and 14 SB2 B-type binaries. A further 20 systems (classified as SB1*) show clear signs of periodicity but with more tentative periods. Orbital solutions are presented for these 84 systems, providing the largest homogeneous sample to date of the binary properties of early B-type stars. Our derived orbital-period distribution is generally similar to those for samples of more massive (O-type) binaries in both the LMC and the Galaxy. This similarity with the properties of the more massive O-type binaries is important as early B-type stars are expected to account for the majority of core-collapse supernovae. Differences in the period distributions of the different samples start to increase above 4 d, and are also present between the earliest (B0-0.7) and later-type (B1-2.5) systems within the BBC sample, although further study is required to understand if this is an observational bias or a real physical effect. We have examined the semi-amplitude velocities and orbital periods of our sample to identify potential candidates that could hide compact companions. Comparing with probability distributions of finding black hole companions to OB-type stars from a recent theoretical study, we have found 16 binaries in the higher probability region that warrant further study.

中文翻译：

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B 型双星表征程序 I. 剑鱼座 30 种群的轨道解

我们展示了 B 型双星表征 (BBC) 计划的结果，该计划是对大麦哲伦星云 (LMC) 剑鱼座 30 区域中 88 个早期 B 型双星候选者的多时期光谱研究。通过对 29 个观测时期的径向速度分析，我们确认了 64 个目标的双星状态，包括 50 个 SB1 和 14 个 SB2 B 型双星。另有 20 个系统（分类为 SB1*）显示出明显的周期性迹象，但具有更多的暂定周期。为这 84 个系统提供了轨道解决方案，为早期 B 型恒星的双星特性提供了迄今为止最大的均质样本。我们推导出的轨道周期分布通常与 LMC 和银河系中更大质量（O 型）双星样本的相似。这种与更大质量的 O 型双星特性的相似性很重要，因为早期的 B 型恒星预计将占核心坍缩超新星的大部分。不同样本的周期分布差异在 4 d 以上开始增加，并且在 BBC 样本中的最早 (B0-0.7) 和较晚类型 (B1-2.5) 系统之间也存在，尽管需要进一步研究才能理解如果这是观察偏差或真实的物理效应。我们已经检查了我们样本的半振幅速度和轨道周期，以确定可能隐藏紧凑同伴的潜在候选者。与最近一项理论研究中发现 OB 型恒星的黑洞伴星的概率分布相比，我们在高概率区域发现了 16 个双星，值得进一步研究。