论文标题
由细丝碎片形成的分子云核的角动量的演变
Evolution of the Angular Momentum of Molecular Cloud Cores Formed from Filament Fragmentation
论文作者
论文摘要
分子云核的角动量在恒星形成过程中起着至关重要的作用。然而，分子云芯角动量的时间演变尚不清楚。在本文中，我们进行了三维模拟，以研究通过细丝碎片形成的分子云核的角动量的时间演变。结果，我们发现大多数核心旋转垂直于细丝轴。在岩体的初始阶段，岩心的平均角动量仅变化约30％，然后几乎保持恒定。此外，我们分析了核心的内部角动量结构。尽管核心从其父丝的初始湍流速度波动中获得了各种方向，但每个核心中的角动量轮廓会收敛到自相似溶液。我们还表明，芯中角动量结构的复杂程度随时间稍微降低。此外，我们执行合成观察结果，并表明从合成平均速度图测量的角动量曲线与考虑到灯丝倾斜度时的观测值兼容。本研究表明，核心形成理论是从细丝碎片中形成的理论，其中核心的角动量结构取决于沿细丝的速度波动确定，并且两者都与观测值兼容。该理论还提供了有关可以在观察测试的核心特性的新见解。
The angular momentum of molecular cloud cores plays an essential role in the star formation process. However, the time evolution of the angular momentum of molecular cloud cores is still unclear. In this paper, we perform three-dimensional simulations to investigate the time evolution of the angular momentum of molecular cloud cores formed through filament fragmentation. As a result, we find that most of the cores rotate perpendicular to the filament axis. The mean angular momentum of the cores changes by only around 30% during the initial stage of their formation process and then remains almost constant. In addition, we analyze the internal angular momentum structure of the cores. Although the cores gain angular momentum with various directions from the initial turbulent velocity fluctuations of their parent filaments, the angular momentum profile in each core converges to the self-similar solution. We also show that the degree of complexity of the angular momentum structure in a core slightly decreases with time. Moreover, we perform synthetic observations and show that the angular momentum profile measured from the synthetic mean velocity map is compatible with the observations when the filament inclination is taken into account. The present study suggests a theory of core formation from filament fragmentation where the angular momentum structures of the cores are determined by the velocity fluctuation along the filaments and both are compatible with the observations. This theory also provides new insights on the core properties that could be observationally tested.
