Dynamical friction in constant density cores: a failure of the Chandrasekhar formula
Dynamical friction in constant density cores: a failure of the Chandrasekhar formula
复制标题
等密度岩心中的动摩擦：钱德拉塞卡公式的失败
DOI：
10.1111/j.1365-2966.2006.11022.x
复制
发表时间：
2006
影响因子：
4.8
通讯作者：
J. S. Lake
中科院分区：
文献类型：
--
作者：
J. Read;T. Goerdt;B. Moore;A. Pontzen;J. S. Lake
通过分析计算和 N 体模拟，我们表明，在恒定密度（谐波）核心中，下沉的卫星会经历非常快速（超钱德拉塞卡）动态摩擦的初始阶段，之后它们根本不会经历动态摩擦。对于具有中心幂律分布的密度分布 ρ∝r−α，坠落的卫星会加热背景并导致 α 减小。当 α < 0.5 时，卫星最初会产生一个小的中心恒定密度核心，并像 α= 0 的情况一样失速。
我们讨论了我们的结果在衰变卫星轨道、银河棒和超大质量黑洞双星合并方面的一些天体物理学应用。在一篇配套论文中，我们表明中心恒定密度核心可以为 Fornax 球状星团的计时问题提供自然的解决方案。
Using analytic calculations and N-body simulations we show that in constant density (harmonic) cores, sinking satellites undergo an initial phase of very rapid (super-Chandrasekhar) dynamical friction, after which they experience no dynamical friction at all. For density profiles with a central power law profile, ρ∝r−α, the infalling satellite heats the background and causes α to decrease. For α < 0.5 initially, the satellite generates a small central constant density core and stalls as in the α= 0 case.
We discuss some astrophysical applications of our results to decaying satellite orbits, galactic bars and mergers of supermassive black hole binaries. In a companion paper we show that a central constant density core can provide a natural solution to the timing problem for Fornax's globular clusters.