论文标题
动力自我摩擦:群众损失如何减慢您的速度
Dynamical self-friction: how mass loss slows you down
论文作者
论文摘要
我们研究了动态自我摩擦,这是从subhalo torquers剩余的残留物中剥离的材料的过程,从而导致其失去轨道角动量。通过在分析宿主光环潜能中运行对轨道轨道轨道的理想化模拟,我们将由于宿主光晕引起的传统动力学摩擦的效果隔离开来。虽然在subhalo的轨道上的某些点上,剥离材料的扭矩可以增强残留物的轨道角动量,而长期内的净效应是轨道衰变,无论初始轨道参数或subhalo质量是什么。为了量化自我摩擦的强度,我们运行了一套跨越典型的宿主与苏巴洛质量比和轨道参数的模拟。我们发现,自界的时间尺度被定义为尺骨轨道角动量的指数衰减时间,质量比和轨道圆形的比例与标准动力学摩擦相似。由于自我摩擦而引起的衰减时间大约是一个数量级的时间更长,这表明自差仅在10%的水平上贡献。但是,沿着更多的径向轨道,自摩擦偶尔可能会在接近上十分之一通道的动态摩擦上占主导地位,而质量剥离是强烈的。这也是自我摩擦扭矩在大小和方向上发生巨大和快速变化的时期,表明自摩擦是在建模亚乳子的周围通道及其相关卫星星系时要考虑的重要过程。
We investigate dynamical self-friction, the process by which material that is stripped from a subhalo torques its remaining bound remnant, which causes it to lose orbital angular momentum. By running idealized simulations of a subhalo orbiting within an analytical host halo potential, we isolate the effect of self-friction from traditional dynamical friction due to the host halo. While at some points in a subhalo's orbit the torque of the stripped material can boost the orbital angular momentum of the remnant, the net effect over the long term is orbital decay regardless of the initial orbital parameters or subhalo mass. In order to quantify the strength of self-friction, we run a suite of simulations spanning typical host-to-subhalo mass ratios and orbital parameters. We find that the time-scale for self-friction, defined as the exponential decay time of the subhalo's orbital angular momentum, scales with mass ratio and orbital circularity similar to standard dynamical friction. The decay time due to self-friction is roughly an order of magnitude longer, suggesting that self-friction only contributes at the 10 percent level. However, along more radial orbits, self-friction can occasionally dominate over dynamical friction close to pericentric passage, where mass stripping is intense. This is also the epoch at which the self-friction torque undergoes large and rapid changes in both magnitude and direction, indicating that self-friction is an important process to consider when modeling pericentric passages of subhaloes and their associated satellite galaxies.