High-resolution studies of massive primordial haloes
High-resolution studies of massive primordial haloes
复制标题
大量原始晕的高分辨率研究
DOI：
10.1093/mnras/sts659
复制
发表时间：
2013
影响因子：
4.8
通讯作者：
Niemeyer
中科院分区：
文献类型：
--
作者：
Schleicher;D. R. G;Schmidt;Niemeyer
维里温度Tvir≥104K的原子冷却晕是第一个星系和第一个中等质量黑洞形成的最可能的场所。因此，评估是否能够从数值模拟中获得有关其主要特性的稳健结果非常重要。主要的不确定性是湍流的存在，这在宇宙学模拟中几乎无法解决。我们通过对每条牛仔裤长度多达 64 个单元进行高分辨率模拟以及结合亚网格尺度湍流模型来解释未解析尺度上的湍流压力和粘度来探索后者。我们发现晕中的主要物理量，特别是密度、温度和能量密度分布，近似收敛。然而，随着分辨率的提高，中央 500 个天文单位的形态发生显着变化，并且显得更加混乱。在对三个不同晕的系统比较中，我们进一步发现湍流亚网格尺度模型产生了更紧凑的中心结构并减少了涡量。这种紧凑的形态可能特别有利于中心物体的吸积。
Atomic cooling haloes with virial temperaturesTvir≥ 104K are the most plausible sites for the formation of the first galaxies and the first intermediate-mass black holes. It is therefore important to assess whether one can obtain robust results concerning their main properties from numerical simulations. A major uncertainty is the presence of turbulence, which is barely resolved in cosmological simulations. We explore the latter both by pursuing high-resolution simulations with up to 64 cells per Jeans length and by incorporating a subgrid-scale turbulence model to account for turbulent pressure and viscosity on unresolved scales. We find that the main physical quantities in the halo, in particular the density, temperature and energy density profile, are approximately converged. However, the morphologies in the central 500 au change significantly with increasing resolution and appear considerably more turbulent. In a systematic comparison of three different haloes, we further found that the turbulence subgrid-scale model gives rise to more compact central structures and decreases the amount of vorticity. Such compact morphologies may in particular favour the accretion on to the central object.