A universal density slope - Velocity anisotropy relation for relaxed structures
A universal density slope - Velocity anisotropy relation for relaxed structures
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DOI：
10.1016/j.newast.2005.09.001
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发表时间：
2006-03-01
期刊：
影响因子：
2
通讯作者：
Moore, B
中科院分区：
文献类型：
--
作者：
Hansen, SH;Moore, B
我们确定了平衡结构的径向密度斜率 alpha(r) 和速度各向异性 beta(r) 之间的普遍关系。这种关系适用于各种系统，包括盘状星系合并、球形塌缩以及有或没有冷却的冷暗物质（CDM）晕。我们认为，当假设暗物质或恒星服从 Tsallis 统计时，从基本原理来看，该关系的形状是合理的，在这种情况下，我们仅用一个自由参数拟合 α-β 关系。人们可以利用这一结果来闭合金斯方程，例如根据观测数据构建椭圆星系的质量模型，或者直接为探测实验确定暗物质结构的时间。我们还预测 CDM 晕的渐近中心斜率和各向异性约为 -1 和 0。 (c) 2005 Elsevier B.V. 保留所有权利。
We identify a universal relation between the radial density slope alpha(r) and the velocity anisotropy beta(r) for equilibrated structures. This relation holds for a variety of systems, including disk galaxy mergers, spherical collapses, and cold dark matter (CDM) halos both with and without cooling. We argue that the shape of the relation is reasonable from fundamental principles when the dark matter or stars are assumed to obey Tsallis statistics, and in that case we fit the alpha-beta relation with just one free parameter. One can use this result to close the Jeans equations, for example to construct mass models of elliptical galaxies from observational data or to time dark matter structures directly to detection experiments. We also predict the asymptotic central slope and anisotropy of CDM halos to be approximately -1 and 0. (c) 2005 Elsevier B.V. All rights reserved.