论文标题
嵌入式星形簇中分形和旋转的演变
Evolution of fractality and rotation in embedded star clusters
论文作者
论文摘要
越来越多的观察结果表明，年轻的恒星簇可以保留其形成过程的烙印。特别是，子结构和旋转的程度可能是这些系统形成的母体分子云的崩溃的直接结果。原则上可以洗掉这样的特性，但也可以预计它们会对这些系统的放松产生影响。我们通过湍流巨大的分子云的崩溃，运行并分析了一组十个嵌入式星形簇形成的流体动力学模拟。我们系统地研究了恒星簇的分形，表明它们都是非常基础的（分形维度$ d = 1.0-1.8 $）。我们还发现，随着时间的流逝，分形在小尺度上缓慢降低，而在较长的时间尺度上却持续了大尺度。在演变的每个时间，即使对于稍微进行的监管子结构，旋转的特征都在不同的模拟中发现，证明了父分子气体将其角动量的一部分转移到新的恒星系统中。
More and more observations indicate that young star clusters could retain imprints of their formation process. In particular, the degree of substructuring and rotation are possibly the direct result of the collapse of the parent molecular cloud from which these systems form. Such properties can, in principle, be washed-out, but they are also expected to have an impact on the relaxation of these systems. We ran and analyzed a set of ten hydrodynamical simulations of the formation of embedded star clusters through the collapse of turbulent massive molecular clouds. We systematically studied the fractality of our star clusters, showing that they are all extremely substructured (fractal dimension $D=1.0-1.8$). We also found that fractality is slowly reduced, with time, on small scales, while it persists on large scales on longer timescales. Signatures of rotation are found in different simulations at every time of the evolution, even for slightly supervirial substructures, proving that the parent molecular gas transfers part of its angular momentum to the new stellar systems.
