INFERRING GRAVITATIONAL POTENTIALS FROM MASS DENSITIES IN CLUSTER-SIZED HALOS
INFERRING GRAVITATIONAL POTENTIALS FROM MASS DENSITIES IN CLUSTER-SIZED HALOS
复制标题
从星团大小的光晕中的质量密度推断引力势
DOI：
10.3847/0004-637x/822/1/41
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发表时间：
2016
期刊：
影响因子：
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通讯作者：
N. Kern
中科院分区：
文献类型：
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作者：
C. Miller;Alejo Stark;D. Gifford;N. Kern
我们使用N体模拟来量化星系团大小的晕中的逃逸速度如何映射到ΛCDM宇宙中的引力势。使用球形密度势对和泊松方程，我们发现，物质密度推断的引力势剖面预测逃逸速度剖面内几个百分点的准确性组和集群大小的晕（10 M，相对于临界密度）。从核心外到维里半径外都是准确的。我们明确地将宇宙常数的重要性时，推断潜在的泊松方程。我们认为三个密度模型，并发现Einasto和伽马配置文件提供了一个更好的联合估计的密度和潜在的配置文件比纳瓦罗，弗伦克，和白色配置文件，它不能准确地代表逃逸速度。对于单个晕，测量的逃逸速度和密度推断的电位分布之间的1σ散射很小（<5%）。最后，虽然子晕在粒子速度弥散分布的表示中显示出15%的偏差，但子晕逃逸速度分布与暗物质逃逸速度分布相匹配，精度很高，没有证据表明速度偏差在0.4r200之外。
We use N-body simulations to quantify how the escape velocity in cluster-sized halos maps to the gravitational potential in a ΛCDM universe. Using spherical density-potential pairs and the Poisson equation, we find that the matter density inferred gravitational potential profile predicts the escape velocity profile to within a few percent accuracy for group and cluster-sized halos (10 M , with respect to the critical density). The accuracy holds from just outside the core to beyond the virial radius. We show the importance of explicitly incorporating a cosmological constant when inferring the potential from the Poisson equation. We consider three density models and find that the Einasto and Gamma profiles provide a better joint estimate of the density and potential profiles than the Navarro, Frenk, and White profile, which fails to accurately represent the escape velocity. For individual halos, the 1σ scatter between the measured escape velocity and the density-inferred potential profile is small (<5%). Finally, while the sub-halos show 15% biases in their representation of the particle velocity dispersion profile, the sub-halo escape velocity profile matches the dark matter escape velocity profile to high accuracy with no evidence of velocity bias outside 0.4r200.