A new discrete dynamical friction estimator based on N -body simulations
A new discrete dynamical friction estimator based on N -body simulations
复制标题
一种基于N体模拟的新型离散动摩擦估计器
DOI：
10.1093/mnras/stad036
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发表时间：
2023
影响因子：
4.8
通讯作者：
Faucher-Giguère, Claude-André
中科院分区：
文献类型：
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作者：
Ma, Linhao;Hopkins, Philip F;Kelley, Luke Zoltan;Faucher-Giguère, Claude-André
银河系模拟中一个长期存在的问题是当大质量黑洞粒子的质量与背景模拟粒子相当或小于背景模拟粒子时，如何求解作用在大质量黑洞粒子上的动力学摩擦力。许多基于传统的Brachasekhar DF公式的亚网格模型已经被提出，但是当应用于真实的星系时，Brachasekhar公式中的某些项的定义存在根本的模糊性，并且难以从（空间）离散的模拟数据中评估连续的量。在这项工作中，我们提出了一个新的亚网格DF估计的基础上的离散性质的N体模拟，这也避免了含糊定义的数量在Eschrasekhar的公式。我们测试我们的估计在thegizmocode，发现它同意与高分辨率的模拟DF是完全捕获的，可以忽略不计的额外计算成本。我们还比较了它与一个Ekrasekhar估计，并讨论了它在真实的银河系模拟的应用。
A long-standing problem in galactic simulations is to resolve the dynamical friction (DF) force acting on massive black hole particles when their masses are comparable to or less than the background simulation particles. Many sub-grid models based on the traditional Chandrasekhar DF formula have been proposed, yet they suffer from fundamental ambiguities in the definition of some terms in Chandrasekhar’s formula when applied to real galaxies, as well as difficulty in evaluating continuous quantities from (spatially) discrete simulation data. In this work, we present a new sub-grid DF estimator based on the discrete nature ofN-body simulations, which also avoids the ambiguously defined quantities in Chandrasekhar’s formula. We test our estimator in thegizmocode and find that it agrees well with high-resolution simulations where DF is fully captured, with negligible additional computational cost. We also compare it with a Chandrasekhar estimator and discuss its applications in real galactic simulations.