论文标题
猎户座分子云中丝状结构的物理条件和运动学1
Physical Conditions and Kinematics of the Filamentary Structure in Orion Molecular Cloud 1
论文作者
论文摘要
我们已经研究了用N2H+ 3-2线的猎户座分子云1（OMC1）区域中致密分子气的结构和运动学。围绕Orion KL核心周围的6'x9'（〜0.7 x1.1 PC）已与亚毫米阵列（SMA）和亚毫米望远镜（SMT）绘制了映射。分辨率为〜5.4英寸（〜2300 au）的组合SMA和SMT图像揭示了多个细丝，典型的宽度为0.02-0.03 pc。根据非LTE分析，使用N2H+ 3-2和1-0数据，使用细丝的密度和温度估计为〜10^7 cm-3和〜15-15-20 k，分别是〜10^7 cm-3和〜15-15-20 k，分别估计了细丝的密度和温度。细丝，其中一种显示了核心气体运动的速度和强度的振荡，这可能是OMC1东部的气体动力的振荡，这可能是由于纤维中的M42和M43的污染物所致。 OMC1区域由三个子区域，即北部，西部和南部的KL，具有不同的径向速度，具有急剧的速度过渡。
We have studied the structure and kinematics of the dense molecular gas in the Orion Molecular Cloud 1 (OMC1) region with the N2H+ 3-2 line. The 6'x9' (~0.7x1.1 pc) region surrounding the Orion KL core has been mapped with the Submillimeter Array (SMA) and the Submillimeter Telescope (SMT). The combined SMA and SMT image having a resolution of ~5.4" (~2300 au) reveals multiple filaments with a typical width of 0.02-0.03 pc. On the basis of the non-LTE analysis using the N2H+ 3-2 and 1-0 data, the density and temperature of the filaments are estimated to be ~10^7 cm-3 and ~15-20 K, respectively. The core fragmentation is observed in three massive filaments, one of which shows the oscillations in the velocity and intensity that could be the signature of core-forming gas motions. The gas kinetic temperature is significantly enhanced in the eastern part of OMC1, likely due to the external heating from the high mass stars in M42 and M43. In addition, the filaments are colder than their surrounding regions, suggesting the shielding from the external heating due to the dense gas in the filaments. The OMC1 region consists of three sub-regions, i.e. north, west, and south of Orion KL, having different radial velocities with sharp velocity transitions. There is a north-to-south velocity gradient from the western to the southern regions. The observed velocity pattern suggests that dense gas in OMC1 is collapsing globally toward the high-mass star-forming region, Orion Nebula Cluster.
