Density waves in the shearing sheet - I. Swing amplification
Density waves in the shearing sheet - I. Swing amplification
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剪切片中的密度波 - I. 摆动放大
DOI：
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发表时间：
2000
期刊：
影响因子：
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通讯作者：
B. Fuchs
中科院分区：
文献类型：
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作者：
B. Fuchs
本文重新研究银盘的剪切片模型。其动力学的理论描述基于三个构建块：恒星轨道，其在周转近似中在此描述;确定恒星在相空间中的分布函数的无碰撞玻尔兹曼方程;以及为了考虑盘的自引力的泊松方程。利用这些工具，我开发了一个新的形式主义来描述扰动的剪切片。将其应用到无界剪切片模型中，我再次证明了盘的扰动如何总是演化成摆动放大的密度波，即螺旋臂状的剪切密度增强，当波峰从引导方向摆动到拖尾方向时，密度增强增长和衰减。文中给出了几个剪切岩片中如何诱发这种摆动放大事件的例子。
The shearing sheet model of a galactic disk is studied anew. The theoretical description of its dynamics is based on three building blocks: stellar orbits, which are described here in epicyclic approximation, the collisionless Boltzmann equation determining the distribution function of stars in phase space, and the Poisson equation in order to take account of the self{gravity of the disk. Using these tools I develop a new formalism to describe perturbations of the shearing sheet. Applying this to the unbounded shearing sheet model I demonstrate again how the disturbances of the disk evolve always into swing amplied" density waves, i.e. spiral{arm like, shearing density enhancements, which grow and decay while the wave crests swing by from leading to trailing orientation. Several examples are given how such swing amplication" events are incited in the shearing sheet.