A halo expansion technique for approximating simulated dark matter haloes
A halo expansion technique for approximating simulated dark matter haloes
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用于近似模拟暗物质晕的晕扩展技术
DOI：
10.1111/j.1365-2966.2011.19222.x
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发表时间：
2010
影响因子：
4.8
通讯作者：
C. Frenk
中科院分区：
文献类型：
--
作者：
B. Lowing;A. Jenkins;V. Eke;C. Frenk
我们应用基函数展开方法来创建一个模拟N体暗物质晕的后期生长的随时间演化的密度/势近似。我们演示了如何从水瓶座项目的光环的潜力，可以准确地表示由少量的基函数，并表明光环扩展（HEX）方法提供了一种方法来重放模拟。我们探讨了该技术的准确性水平以及它的一些局限性。我们发现，包括在扩展中的条款的数量必须足够大，以解决大规模的分布和形状的晕，但除此之外，额外的条款导致进一步改善。粒子和subhalo轨道可以集成在这个现实的，随时间变化的晕势近似，在成本比原来的模拟低得多，具有高保真度的许多个人的轨道，和一个很好的匹配轨道能量和角动量的分布。统计上，结构subhalo属性的演变，如质量，半质量半径和特征圆速度，是非常好地再现在HEX近似几个陀螺。我们演示了应用程序的技术，通过以下的演化轨道subhalo在更高的分辨率比可以实现在原来的模拟。我们的方法是一个显着的改进，通常使用的技术的基础上静态分析描述的晕势。
We apply a basis function expansion method to create a time-evolving density/potential approximation of the late growth of simulated N-body dark matter haloes. We demonstrate how the potential of a halo from the Aquarius Project can be accurately represented by a small number of basis functions, and show that the halo expansion (HEX) method provides a way to replay simulations. We explore the level of accuracy of the technique as well as some of its limitations. We find that the number of terms included in the expansion must be large enough to resolve the large-scale distribution and shape of the halo but, beyond this, additional terms result in little further improvement. Particle and subhalo orbits can be integrated in this realistic, time-varying halo potential approximation, at much lower cost than the original simulation, with high fidelity for many individual orbits, and a good match to the distributions of orbital energy and angular momentum. Statistically, the evolution of structural subhalo properties, such as mass, half-mass radius and characteristic circular velocity, are very well reproduced in the HEX approximation over several Gyr. We demonstrate an application of the technique by following the evolution of an orbiting subhalo at much higher resolution than can be achieved in the original simulation. Our method represents a significant improvement over commonly used techniques based on static analytical descriptions of the halo potential.
冷暗物质晕中亚结构的命运
DOI：
10.1111/j.1365-2966.2009.15333.x
发表时间：
2009
影响因子：
4.8
作者：
Angulo R
通讯作者：
Angulo R