GRAPESPH with fully periodic boundary conditions: fragmentation of molecular clouds
GRAPESPH with fully periodic boundary conditions: fragmentation of molecular clouds
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具有完全周期性边界条件的 GRAESPH：分子云的破碎
DOI：
10.1093/mnras/292.1.11
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发表时间：
1997
影响因子：
4.8
通讯作者：
R. Klessen
中科院分区：
文献类型：
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作者：
R. Klessen
提出了一种将周期边界条件下的光滑粒子流体动力学（SPH）方法应用于GRAPE专用设备的方法。GRAPE（GRAvity PipE）通过在专门设计的芯片上直接求和来求解N体系统的泊松方程和力方程，并返回每个粒子的邻居列表。由于其设计，GRAPE不能直接处理周期性粒子分布。GRAPESPH的这种限制可以通过使用PM类方法在主机上计算由于周期性（埃瓦尔德校正）引起的每个颗粒的校正力来克服。
该方案被应用于研究巨分子云的碎裂过程。假设一个纯粹的等温模型，我们遵循的动态演化的内部的分子云开始从高斯初始密度分布的自引力团块的形成，直到大部分的气体被消耗在这些密集的核心。尽管它很简单，但这个模型可以重现观测到的分子云的一些基本性质，比如一个质量分布为$dN/dm \propto m^n$的团块，其中$n ~-1.5$。
A method of adapting smoothed particle hydrodynamics (SPH) with periodic boundary conditions for use with the special purpose device GRAPE is presented. GRAPE (GRAvity PipE) solves the Poisson and force equations for an N-body system by direct summation on a specially designed chip and in addition returns the neighbour list for each particle. Due to its design, GRAPE cannot treat periodic particle distributions directly. This limitation of GRAPESPH can be overcome by computing a correction force for each particle due to periodicity (Ewald correction) on the host computer using a PM-like method.
This scheme is applied to study the fragmentation process in giant molecular clouds. Assuming a pure isothermal model, we follow the dynamical evolution in the interior of a molecular cloud starting from an Gaussian initial density distribution to the formation of selfgravitating clumps until most of the gas is consumed in these dense cores. Despite its simplicity, this model can reproduce some fundamental properties of observed molecular clouds, like a clump mass distribution of the form $dN/dm \propto m^n$, with $n ~ -1.5$.