论文标题
猎户座的灯丝交叉点和冷致密的岩心
Filament Intersections and Cold Dense Cores in Orion A North
论文作者
论文摘要
我们使用高分辨率N2H+（1-0）光谱立方体（用Atacama大毫米/毫米/亚毫米阵列（ALMA）观察到的高分辨率N2H+（1-0）光谱立方体（ALMA），我们研究了Orion A北分子云中OMC-2,3区域中的细丝结构和致密核。发现总长度为2 PC的细丝网络包含170个交叉点和128个候选密集核。密集的岩心都从红外点源（可能的年轻恒星）中移动，而核心的主要部分（103）位于交叉口周围。朝着交叉点，总柱密度NTOT以及柱密度分布函数（N-PDF）的幂律指数的趋势也越来越大，这表明相交通常比丝状路径的其他部分具有更重要的气体组件。病毒分析表明，密集的核心主要具有alpha_vir的病毒质量比= m_vir/m_gas <1.0，这表明它们是由自重力界定的。同时，只有约23％的核心具有alpha_crit = m_crit/m_gas <1.0的临界质量比，这表明它们在核心崩溃的情况下是不稳定的。结合了这些结果，它表明，在OMC-2,3中，Cold无星和可能的Prestellar核心的主要部分正在交叉点周围，目前处于重力结合的状态。但是，更广泛的核心崩溃和恒星形成仍然可能需要连续的核心生长或其他扰动
We studied the filament structures and dense cores in OMC-2,3 region in Orion A North molecular cloud using the high-resolution N2H+ (1-0) spectral cube observed with the Atacama Large Millimeter/Submillimeter Array (ALMA). The filament network over a total length of 2 pc is found to contain 170 intersections and 128 candidate dense cores. The dense cores are all displaced from the infrared point sources (possible young stars), and the major fraction of cores (103) are located around the intersections. Towards the intersections, there is also an increasing trend for the total column density Ntot as well as the the power-law index of the column-density Probability Distribution Function (N-PDF), suggesting that the intersections would in general have more significant gas assembly than the other part of the filament paths. The virial analysis shows that the dense cores mostly have virial mass ratio of alpha_vir=M_vir/M_gas<1.0, suggesting them to be bounded by the self gravity. In the mean time, only about 23 percent of the cores have critical mass ratio of alpha_crit=M_crit/M_gas<1.0, suggesting them to be unstable against core collapse. Combining these results, it shows that the major fraction of the cold starless and possible prestellar cores in OMC-2,3 are being assembled around the intersections, and currently in a gravitationally bound state. But more extensive core collapse and star formation may still require continuous core-mass growth or other perturbatio
