A Cool Magnetized Shell Wrapped around the Hot H II Region S106: Geometry, Kinematics, Magnetic Vectors, and Pressure Balance
A Cool Magnetized Shell Wrapped around the Hot H II Region S106: Geometry, Kinematics, Magnetic Vectors, and Pressure Balance
复制标题
包裹在热 H II 区域 S106 周围的冷磁化壳：几何、运动学、磁矢量和压力平衡
DOI：
10.1086/430341
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发表时间：
2005
期刊：
影响因子：
--
通讯作者：
J. Fiege
中科院分区：
文献类型：
--
作者：
J. Vallée;J. Fiege
在光学上，令人兴奋的星星S106 IR位于一个明显的尘埃带中，它在尘埃带的两侧电离了两个明亮，尖锐的气体瓣。包裹在这个热（10，000 K）电离（H II）光学双极星云（两个气体叶）周围，我们看到毫米-亚毫米射电中的冷壳。在冷壳层的外面，有一个更冷（<22 K）、更大（20′ = 4 pc）、密度更低的分子云。在本文中，我们研究了冷气体（三条谱线），冷尘埃（连续成像），并在壳层的磁场（偏振），都取得了近850 μm的波长与相同的角分辨率为14“的詹姆斯克拉克麦克斯韦望远镜（JCMT）。在径向速度为-1 km s-1附近，我们使用J = 3-2线中的12 CO、13 CO和C18 O来映射热腔壁两侧壳峰中的冷（32 K）气体，南北长2'（0.4 pc），东西直径为100“（0.3 pc）。此外，我们还利用尘埃的连续辐射及其线偏振来绘制冷壳层。对于夹在热区域和冷云之间的垂直冷壳层，我们发现壳层的总压力（主要由湍流和总磁场组成）可以承受热电离流出的湍流和热压力，尽管冷气体壳层正在缓慢地被电离过程侵蚀。大尺度磁场沿着大致垂直的气体壳层出现大致垂直的沿着。垂直壳层（远离中心尘埃带）的磁场估计值接近400 μG。在水平尘埃带中，磁场大致水平并平行于包含IR和FIR分量的尘埃带。在这里，从各种方法得出的磁场估计的天平面中值接近570 μG，而先前发表的塞曼数据表明视线强度接近+240 μG。
In the optical, the exciting star S106 IR resides in a conspicuous dust lane and it ionizes two bright, sharp gas lobes on both sides of the dust lane. Wrapped around this hot (10,000 K) ionized (H II) optical bipolar nebula (the two gas lobes), we see a cool shell in the millimeter-submillimeter radio. Outside the cool shell, there is an even colder (<22 K), large (20′ = 4 pc), lower density molecular cloud. In this paper, we study the cool gas (spectroscopy in three lines), the cool dust (continuum imaging), and the magnetic field (polarimetry) in the shell, all made near a wavelength of 850 μm with the same angular resolution of 14'' using the James Clerk Maxwell Telescope (JCMT). Near a radial velocity of -1 km s-1, we used 12CO, 13CO, and C18O in the J = 3-2 lines to map the cool (32 K) gas in the shell peaks on both sides of the hot cavity walls, extending 2' (0.4 pc) in north-south length with a 100'' (0.3 pc) east-west diameter. Also, we used dust continuum emission and its linear polarization to map the cool shell. For the vertical cool shell, sandwiched between a hot region and a colder cloud, we find that the shell's combined pressure (made up mostly of turbulence and total magnetic field) can withstand the turbulent and thermal pressure of the hot ionized outflow, although the cool gas shell is slowly being eroded by the ionization process going on. The large-scale magnetic field appears roughly vertical along the roughly vertical gas shell. The magnetic field in the vertical shell (away from the central dust lane) has an estimated value near 400 μG. In the horizontal dust lane, the magnetic field appears roughly horizontal and parallel to the dust lane encompassing the IR and FIR components. Here the magnetic field derived from various methods has an estimated plane-of-sky median value near 570 μG, while the previously published Zeeman data indicated a line-of-sight strength near +240 μG.