Radial distribution and strong lensing statistics of satellite galaxies and substructure using high‐resolution ΛCDM hydrodynamical simulations
Radial distribution and strong lensing statistics of satellite galaxies and substructure using high‐resolution ΛCDM hydrodynamical simulations
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DOI：
10.1111/j.1365-2966.2005.09976.x
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发表时间：
2005-06
影响因子：
4.8
通讯作者：
A. Macciò;B. Moore;J. Stadel;J. B. U. O. Zurich;University of California at Santa Cruz
中科院分区：
文献类型：
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作者：
A. Macciò;B. Moore;J. Stadel;J. B. U. O. Zurich;University of California at Santa Cruz
我们分析的数量密度和径向分布的子结构和卫星星系使用宇宙学模拟，遵循气体动力学的重子组件，包括冲击加热，辐射冷却和星星形成的层次一致性λ冷暗物质模型。我们发现，重子的耗散大大提高了subhaloes的生存，特别是在星系的核心，导致卫星星系的径向分布，密切遵循整体质量分布。流体动力学模拟是必要的，以解决绝热收缩和致密的核心星系，导致卫星的总数比纯暗物质模拟中发现的大2倍，与观测到的星系和星系团内的卫星星系的空间分布很好地吻合。收敛性测试表明，以前的作者在纯N体模拟中发现的核心分布是由于暗物质结构的物理过度合并。我们继续使用射线拍摄技术来研究这些额外子结构对尖点焦散放大关系违反次数的影响。我们开发了一种新的方法，试图解开子结构的N体模拟的内在离散性的影响。即使星系中心的子结构数量增加，我们也无法重现在多透镜类星体的通量比中观察到的大量差异。
We analyse the number density and radial distribution of substructures and satellite galaxies using cosmological simulations that follow the gas dynamics of a baryonic component, including shock heating, radiative cooling and star formation within the hierarchical concordance Lambda cold dark matter model. We find that the dissipation of the baryons greatly enhances the survival of subhaloes, especially in the galaxy core, resulting in a radial distribution of satellite galaxies that closely follows the overall mass distribution. Hydrodynamical simulations are necessary to resolve the adiabatic contraction and dense cores of galaxies, resulting in a total number of satellites a factor of 2 larger than that found in pure dark matter simulation, in good agreement with the observed spatial distribution of satellite galaxies within galaxies and clusters. Convergence tests show that the cored distribution found by previous authors in pure N-body simulations was due to the physical overmerging of dark matter only structures. We proceed to use a ray-shooting technique in order to study the impact of these additional substructures on the number of violations of the cusp caustic magnification relation. We develop a new approach to try to disentangle the effect of substructures from the intrinsic discreteness of N-body simulations. Even with the increased number of substructures in the centres of galaxies, we are not able to reproduce the observed high numbers of discrepancies observed in the flux ratios of multiply lensed quasars.