Two-point Separation Functions for Modeling Wide Binary Systems in Nearby Dwarf Galaxies
Two-point Separation Functions for Modeling Wide Binary Systems in Nearby Dwarf Galaxies
复制标题
邻近矮星系中宽双星系统的两点分离函数
DOI：
10.3847/1538-4357/ac5b5f
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发表时间：
2021-07
期刊：
影响因子：
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通讯作者：
Christopher Kervick;M. Walker;J. Peñarrubia;Sergey E. Koposov
中科院分区：
文献类型：
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作者：
Christopher Kervick;M. Walker;J. Peñarrubia;Sergey E. Koposov
我们使用的几何方法来获得（二维）分离功能对指定的位置函数dN/dR的人口内的对象。我们提出了一个均匀的表面密度对应的分离函数的解析解在一个圆形的领域，一个普卢默球（投影），和混合物，其中包括两个子群内的二进制对象的贡献。这些结果使推论二进制对象人口通过直接建模的对象位置和对分离数据，而不诉诸于标准的两点相关函数的估计。分析模拟数据集，旨在模仿已知的矮球状星系，我们证明了恢复输入属性的能力，包括宽二元星星系统的数量，以及在分辨二元对的数量假设为几百个的情况下，特征特征（例如，陡峭化和/或截断）。结合即将到来的观测能力，这种方法打开了一个窗口的形成和/或生存的广泛的二元人口在矮星系，并提供了一种新的探测推断暗物质的子结构上的最小的星系尺度。
We use a geometric method to derive (two-dimensional) separation functions among pairs of objects within populations of specified position function dN/dR . We present analytic solutions for separation functions corresponding to a uniform surface density within a circular field, a Plummer sphere (viewed in projection), and the mixture thereof—including contributions from binary objects within both subpopulations. These results enable inferences about binary object populations via direct modeling of object position and pair separation data, without resorting to standard estimators of the two-point correlation function. Analyzing mock data sets designed to mimic known dwarf spheroidal galaxies, we demonstrate the ability to recover input properties including the number of wide binary star systems and, in cases where the number of resolved binary pairs is assumed to be ≳a few hundred, characteristic features (e.g., steepening and/or truncation) of their separation function. Combined with forthcoming observational capabilities, this methodology opens a window onto the formation and/or survival of wide binary populations in dwarf galaxies, and offers a novel probe of inferred dark matter substructure on the smallest galactic scales.