Dark matter halo merger histories beyond cold dark matter – I. Methods and application to warm dark matter
Dark matter halo merger histories beyond cold dark matter – I. Methods and application to warm dark matter
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DOI：
10.1093/mnras/sts159
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发表时间：
2012-09
影响因子：
4.8
通讯作者：
A. Benson;A. Farahi;S. Cole;L. Moustakas;A. Jenkins;M. Lovell;R. Kennedy;J. Helly;Carlos Frenk Carneg
中科院分区：
文献类型：
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作者：
A. Benson;A. Farahi;S. Cole;L. Moustakas;A. Jenkins;M. Lovell;R. Kennedy;J. Helly;Carlos Frenk Carneg
我们描述了一种使用广义扩展 Press-Schechter 形式主义的自洽处理来准确计算非冷暗物质宇宙中的晕质量函数、祖质量函数、合并率和合并树的方法。我们的方法允许在具有各种不同粒子特性的暗物质模型或具有滚动、截断或更复杂功率谱的宇宙中快速探索星系晕的亚晕群体。我们将分析得出的质量函数和合并历史与最近的暖暗物质宇宙学 N 体模拟进行了详细比较，并发现了极好的一致性。我们表明，一旦考虑到平滑分布物质的吸积，诸如晕的质量吸积历史之类的粗粒度统计数据在冷暗物质情况和暖暗物质情况之间几乎无法区分。然而，晕质量函数和祖质量函数存在显着差异，暖暗物质情况被强烈抑制在暗物质的自由流动尺度以下。我们证明了对暖暗物质中的偏移集势垒首次穿越分布使用正确解的重要性 - 如果改用平坦势垒的解，则晕质量函数的截断速度要慢得多，导致高估低质量晕的数量。
We describe a methodology to accurately compute halo mass functions, progenitor mass functions, merger rates and merger trees in non-cold dark matter universes using a self-consistent treatment of the generalized extended Press–Schechter formalism. Our approach permits rapid exploration of the subhalo population of galactic haloes in dark matter models with a variety of different particle properties or universes with rolling, truncated or more complicated power spectra. We make detailed comparisons of analytically derived mass functions and merger histories with recent warm dark matter cosmological N-body simulations, and find excellent agreement. We show that once the accretion of smoothly distributed matter is accounted for, coarse-grained statistics such as the mass accretion history of haloes can be almost indistinguishable between cold and warm dark matter cases. However, the halo mass function and progenitor mass functions differ significantly, with the warm dark matter cases being strongly suppressed below the free-streaming scale of the dark matter. We demonstrate the importance of using the correct solution for the excursion set barrier first-crossing distribution in warm dark matter – if the solution for a flat barrier is used instead, the truncation of the halo mass function is much slower, leading to an overestimate of the number of low-mass haloes.