Observational Constraints on Binary Star Formation

9526034 HeCox将要开展的研究的目标是推导出对双星系统形成理论的可靠的观测约束。目前对与其形成相关的双星系统的整体特征知之甚少。特别是，我们不知道双星系统中次星的质量是否与主星和单星的质量分布相同。关于双星的轨道角动量的数值和范围，人们几乎一无所知。最后一个问题特别重要，因为双星轨道可以作为形成系统的致密云核的原始角动量的储存库，从而有助于形成恒星形成所需的中心集中的物质。为了纠正这些缺陷，需要可靠地估计半长轴和次要/初级质量比的联合分布，作为一个整体来表征双星。推导这种分布的方法是统计建模的方法，其中所需本征特征(半长轴、质量比)的分布与可观测量(轨道周期、速度等)的分布相关。以确定的方式保留数据中的所有信息。将使用数学上严格的方法来建立这种模型，以及使用它们的统计反转的手段，从可观测数据的内在分布中推断出所需的内在分布。将给出所有观测双星类型(光谱、可见光等)的模型轮廓。这些模型将与最近和未来对双星系统进行的无偏观测调查的数据一起使用，以确定表征同质初级类型双星系统的半长轴和质量大鼠IO的联合分布。这些特征的分布可以用来直接确定表征双星系统整体的二次质量函数和轨道角动量值的分布(以及其他动力学特征)。由此产生的分布将构成对恒星形成的主要模式(大多数恒星是双星系统的成员)的第一个真正有意义的观测约束。这将有助于确定当前的双星形成理论在多大程度上是正确的，并促进我们对恒星形成过程的总体理解。***

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. ***