引力不稳定性在巨分子云的形成和演化中的作用

为了研究引力不稳定性在巨分子云形成中的作用,通过计算机模拟技术建立了星系中分子云的较差自转模型.在演化中除了分子云之间的碰撞外,模型还考虑了分子云在恒星盘的背景引力场中所受的引力和分子云之间的相互自引力.其中分别考虑分子云之间的短程力(随机碰撞模型)和长程力(引力不稳定性模型).通过对计算机模拟的结果进行详细的分析和讨论,得到了以下结果:对于较差自转模型,引力不稳定性在巨分子云的聚合形成中起了关键的积极作用,它能够加速和加大分子云的成团.

THE EFFECT OF GRAVITATIONAL INSTABILITY ON THE FORMATION AND EVOLUTION OF GIANT MOLECULAR CLOUDS IN GALAXIES

In order to study the effect of the gravitational instability in the formation and evolution of giant molecular cloud models (GMCs) in galaxies, the differential rotation models are developed by means of computer simulation methods. In addition to the collision between clouds, both the forces induced by the background potential of star disk and the self-gravity among molecular clouds are involved. As for the self-gravity, the short range (random collision model) and long-range self-gravity (gravitational instability model) among clouds is considered respectively. The results obtained are summarized as follows: The gravitational instability plays a key positive role in the aggregation formation of GMCs for the differential rotation model, and can speed up the clumping of GMC to form more massive GMCs.