On the Structure of the Orion A Cloud and the Formation of the Orion Nebula Cluster
On the Structure of the Orion A Cloud and the Formation of the Orion Nebula Cluster
复制标题
DOI：
10.1086/509321
复制
发表时间：
2006-09
期刊：
影响因子：
--
通讯作者：
L. Hartmann;A. Burkert
中科院分区：
文献类型：
--
作者：
L. Hartmann;A. Burkert
我们认为猎户座A星云在大尺度上是引力坍缩的，并通过有限的云几何形状内引力的聚焦效应产生猎户座星云团。为了支持这一观点，我们展示了一个椭圆形的旋转气体层，沿着长轴沿着具有适度的密度梯度，它是如何坍缩产生一个定性上类似猎户座A的结构的，一端是扇形结构，沿着扇形沿着是脊或细丝，另一端是一个狭窄的弯曲细丝，让人想起著名的积分形细丝。该模型在狭窄的灯丝内产生了局部的质量集中，原则上可以形成像猎户座星云那样的密集星团。我们认为，全球引力收缩可能是一个更常见的分子云的特征比以前认识到的，和星星集群的形成是一个动态的过程中产生的重力作用于有限的云的几何形状的聚焦效应。
We suggest that the Orion A cloud is gravitationally collapsing on large scales, and is producing the Orion Nebula Cluster through the focusing effects of gravity acting within a finite cloud geometry. In support of this suggestion, we show how an elliptical rotating sheet of gas with a modest density gradient along the major axis can collapse to produce a structure qualitatively resembling Orion A, with a fan-shaped structure at one end, ridges or filaments along the fan, and a narrow curved filament at the other end reminiscent of the famous integral-shaped filament. The model produces a local concentration of mass within the narrow filament, which in principle could form a dense cluster of stars like that of the Orion Nebula. We suggest that global gravitational contraction might be a more common feature of molecular clouds than previously recognized, and that the formation of star clusters is a dynamic process resulting from the focusing effects of gravity acting on the geometry of finite clouds.