Observational Constraints on Binary Star Formation

双星形成的观测限制

• 批准号: 9526034
• 负责人: William Heacox
• 金额: $ 7.44万
• 依托单位: University of Hawaii
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1996
• 资助国家: 美国
• 起止时间: 1996-05-15 至 1998-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9526034&HistoricalAwards=false
• 关键词: Observational; Constraints; Binary; Star; Formation

9526034 Heacox The objective of the research to be carried is to deduce reliable observational constraints on the theories of the formation of binary star systems. There is very little currently known about the overall binary stellar system characteristics which are relevant to their formation. In particular, we do not know whether the masses of the secondary stars in binary systems are distributed in the same manner as those of primary and single stars. There is almost no knowledge of the values and ranges of the orbital angular momenta values characterizing binary stars. This last issue is particularly important, since binary star orbits may act as the repositories of the original angular momentum of the dense cloud cores from which the systems form, thus aiding in the formation of the central concentration of material necessary for star formation. A reliable estimate of the joint distribution of semi-major axes and secondary/primary mass ratios, characterizing binaries as a whole, is needed to correct these deficiencies. The method for deducing this distribution is that of statistical modeling, wherein the distributions of the desired intrinsic characteristics (semi-major axes, mass ratios) are related to those of the observable quantities (orbital periods, velocities, etc.) in a deterministic manner that preserves all the information in the data. Mathematically rigorous methods of developing such models will be used, as well as the use of the means of their statistical inversion, to infer the desired intrinsic distribution from that of the observables. Model outlines will be given for all observational binary star types (spectroscopic, visible, etc.). These models will be used with the data, from recent and future observationally unbiased surveys of binary star systems, to determine the joint distributions of semi-major axes and mass rat ios characterizing binary star systems of homogeneous primary types. These distributions of characteristics may then be used to directly determine the secondary mass function and distribution of orbital angular momentum values (and other dynamic characteristics) characterizing binary star systems as a whole. The resulting distributions will constitute the first truly meaningful observational constraints on the dominant mode of star formation (most stars are members of binary systems). This will help to determine the extent to which any of the current theories of binary star formation are correct, and advance our understanding of the process of star formation in general. ***

小行星9526034 进行研究的目的是推导出对双星星系统形成理论的可靠的观测限制。目前对与它们形成相关的双星系统的总体特征知之甚少。 特别是，我们不知道双星系统中的次级星的质量是否与主星和单星的质量分布相同。 几乎没有人知道 轨道角动量的值和范围 价值表征 双星 最后一个问题 是 特别重要的是，由于双星星星轨道可能充当稠密云核的原始角动量的储存库，系统来自这些云核 形式， 从而有助于形成 的 形成星星所必需的物质的中心集中区。 可靠估计 的 的 半大调联合分布 轴 而二次/一次质量比，作为一个整体来表征双星，则需要纠正这些缺陷。 推导该分布的方法 是 的 统计 建模， 其中 所希望的本征特性（半长轴、质量比）的分布与可观测量（轨道周期、速度等）的分布有关。以确定性的方式保存数据中的所有信息。 将使用数学上严格的方法来开发这种模型，以及使用其统计反演的手段，从可观测量的分布中推断出所需的内在分布。 将给出所有观测双星星星类型（光谱型、可见型等）的模型概要。 这些模型将与最近和将来的观测无偏双星星星系统的调查数据一起使用，以确定表征同质主要类型的双星星星系统的半长轴和质量率的联合分布。 这些特征分布可直接用于确定次级质量函数和轨道角分布 势头 值 (and其他 动态 特征）表征作为一个整体的双星星星系统。 由此产生的分布将构成对星星形成主导模式的第一个真正有意义的观测约束（大多数恒星是双星系统的成员）。 这将有助于确定目前的任何双星星形成理论在多大程度上是正确的，并促进我们对星星形成过程的理解。 ***